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PUD, SPR Civil & Stormwater Review q0 ,fTgst Sj. /W5 Truces wul PUO; SP: CA 1 t S+oy,mw Vi eW i if right tab fold 12" INV IN=11/.20 1 ' t �• I 1 { 12" INV OUT=116.95 BOTTOM OF TANK=112.87 1 n PROP ; +1 I t2J5:117.65 tV=t,'3.31 12" INVs=113.10 "''t l - PROP. SHALLOW DMH RIM=119.36 12" INVs=116.00 15 Cd R GA.RAG j 1 } - ` I I { Y 117.715 - +1165� ° -- - -PROPOSED STORMWATER PROP. SHALLOW DMH I' MANAGEMENT AREA 1_ RIM=115.5 / v (INFILTRATION POND 7P) 4 INV IN=113.0 (72) CULTEC 330XL CHAMBERS 12" INVs=112.5 {` TOP OF STONE=1'16.25 TOP OF CHAMBERS=115.75 ----- ".-. 12" INV IN=114.75 ' PROPp SEDIMENT 12" INV OUT=113.50 - & OIL SE TOR" (SOS 15S T BOTTOM OF CHAMBERS-113.21 RIMS=114.2 ,500 GALLQN) BOTTOM OF STONE=109.21 TOP OF TANK _ 7g { INSPECTION PORTS TO FINISH GRADE 12" INV IN=110"20;; 12" INV OUT=109.95 i p t :PROPOSED STORMWATER MANAGEMENT AREA BOTTOM OF TANK=Y05 87 1 ,a �< (INFILTRATION POND 6P) PROP. SHALLOW DMH = C' (50) CULTEC 330XL CHAMBERS RIM=114.0 i { TOP OF STONE-114.50 ° 12 INV IN=108.25 ca' rn ;_. TOP OF CHAMBERS=114.0 12" INVs=108.33 I + �' 12" INV IN=113.00 4" INV OUT=113.67 'PROPOSED STORMWATER u f • MANAGEMENT AREA BOTTOM OF CHAMBERS=111.46 3 I BOTTOM OF STONE=107.46 (INFILTRATION POND 5P) x" I; ® . INSPECTION PORTS TO FINISH GRADE (60) CULTEC 330XL CHAMBERS TOP OF STONE=110.0 k 1, i8"INV.=107.0t TOP OF CHAMBERS=109.50 l _12" INV IN=108.50 �I u ir" i 12" INV OUT=108.50 i BOTTOM OF CHAMBERS=106.96 BOTTOM OF STONE=102.96 { INSPECTION PORTS TO FG I, au PROPOSED SEDIMENT 1D -tl-a & OIL SEPARATOR (SOS 12S) { alrr �j: y RIMs=107.00 (2,000 GALLON) TOP OF TANK=105.79 or Ir 12" INV IN= 104.20 � PRQP.. DMH �1 l 12" INV OUT 103.95 i RIM=107.5 Ij -d BOTTOM OF TANK=99 (2) 8" INV'S=102.58 12" INVs=102.25 �6 FIRE DMH RIM 08.0=.'1 01 12" INVs=104.0 EX C ��P_ERF .NDP I RIM=13---- E>,• DMH RCP INV=100.73 RIM=106.73 ` - 36" RCP_ INV 102 83 _ . fi,�&-= 83--: SS _0 3 � Z �• »� _.._. r �Ip� ERA S 5 d) WATER SMH -� = RAISE PAVED OVER DRAIN TEES-�_ 0 1 MANHOLE TO FINISH GRADE p --- O �RI;M=.>105.23 BBI r w (A R0 RUCTION DURING CONST 15 CIP INV=99 .-a 'WATER"- W ..LOA1. ,.W ff 12, WATER EX SMH -- 0 OA7E . r = -_ to %:n�tas CONNECT TO WATER w MAW � 15 CIP INV=99.69 Response to August 30,2018 Peer Review by NECE 40 First Street/45 Traders Way September 5,2018 impervious surfaces to one acre or less; providing pool storage in the first chamber of 400 cubic feet per acre of impervious surface;making the permanent pool equal to 4 feet deep and providing removal covers that allow observation and maintenance. 2 • Extra water valve We have added a 12"water gate to the north-side of the connection from proposed Building 6 to the existing water main,see attached plan excerpt. Sidewalk demo limits r We have enlarged the demo limits to include the removal and repaving of the sidewalks along First Street and Traders Way,see reduced size copy attached. Should you have any additional questions,comments or concerns please do not hesitate to contact , me or Peter Blaisdell by phone or email. Very Truly Yours, Richard L.Williams,P.E. Principal Cc:David Knowlton,City Engineer William M.Ross,P.E. Peter Lutts&Pavel Espinal t I 3 Y" Response to August 30,2018 Peer Review by NECE 40 First Street/45 Traders Way September 5,2018 The wetlands will be protected by maintaining them in their natural state and by the active management of the apartment community.The wetlands will not be disturbed with the exception of removing trash and debris which is currently littering the area. The wetlands will be enhanced around the edges by planting native species and seeding the area with a native wildflower mix as well as maintaining their natural look and shape as viewing areas. • Drain alteration permit letter to Engineering Dept. See attached. • Calculations on the existing sewer slopes based on your shots on the inverts that were not included in previous version. We have added the pipe slopes of the existing sewer based on our field measurements to the revised plan. See the attached excerpts of the Utility Plan which will be on the final drawing set. AMC trap compliance info from manufacturer. The configuration shown on our plans are the standard tank provided by Shea • Concrete for their Water Quality Inlet units which are designed to meet the 25% TSS removal requirement found in DEP's Stormwater Management Policy(SMP). It is important to note that in Volume 2,Chapter 2,page 6 of the SMP,the last line of the Oil/Grit Separator states"There are other separators that may be used for spill control." It has always been our experience that the exact configuration shown j in the SMP was to be used as a guideline and not a rule as long as the design met the major design considerations.We will explain further below how we meet them. i Due to the sizing requirement of 400 cubic feet of storage in the first chamber,it was necessary for us to modify the standard Shea design with specific dimensions to provide 1,500 gallon,2,000 gallon and 2,500 gallon based on the amount of impervious area tributary to the individual unit. As you can see in the example given in the SMP,there are no specific dimensions given,depths or sizes of the orifice and the inverted pipe.Also,there are no dimensions of the second or third chambers so the example is very vague in terms of , a workable design that you can utilize on a project development. It is our position that the design that we have submitted is an improvement over the example given in the SMP as it refers back to the 2004 MassHighway Stormwater Handbook for Highways and Bridges.Further,it states below the detail in said Handbook that it is an example. The design for the different unit sizes that we have provided meet the most important design considerations in that we are limiting the contributing area of • t t 2 z _ E r Project file: SALE-0036 LWILLIAMS SPARAGES 4 04UNEERS • PLANNERS •SURVEYORS `+ September 5,2018 Ms.Amanda Chiancola, Staff Planner Office of Planning and Community Development S 98 Washington Street,21 Floor Salem,MA 01970 RE: 40 First Street/45 Traders Way, Salem,MA Traders Village Peter Lutts&Paval Espinal,Applicants Response to Peer Review Comments by New England Civil Engineering Corp.(NECE) Dear Amanda, The purpose of this letter is to respond to outstanding items and comments provided to us by William Ross,P.E.of NECE in a letter dated August 30,2018. Since many of the items have been resolved or will be handled with a condition of approval,we have only included those items left to be addressed. The NECE comments are shown below in italics,and,our responses are in the bold text that follows. 4�, Wetland statement about the pre and post runoff volumes and the 5 protection/enhancement statement. i As you can see in the table below from page 1-7 of the Stormwater Report revised through June 27,2018;there will be a slight increase in the rate of stormwater runoff to the wetlands on site in the 2& 10 year storm events but a slight decrease in the 100 year storm. Peak Rate of Runoff Comparison_ Location-_Link 2L Description 2-Year 10-Year 100-Year 24 Hour 24 Hour 24 Hour Type III Type III Type III Storm Event Storm Event Storm Event Existing leak Rate of Runoff(cfs) 6.5 11.3 18.5 Proposed Peak ` Rate of Runoff 7.5 11.9 18.1 (cfs) t Increase/ +1.0 +0.6 -0.4 • Decrease 189 North Main Street, Suite 101 • Middleton, MA 01949 Tel: (978) 539-8088 s www.wsengineers.com { s KIMS=114 Lb .DUU1,1UA UNJ '+ l9� I° uv.Ivia TOP OF TANK 1: 7.9 - INSPECT I 11650 r —r 4 a T' r r6 12" INV IN=110.20 - PROPOE 12" INV OUT=109 95 _ 7 , MANAGE PROS SHALLOWS_CB L �� 1 _ i_ ,_ BOTTOM OF TANK 10587' ca f` !NFl r I I 7U 1 e'III �"" ( LTR f RIMS s 1 1i b . . PROP. SHALLOW DMH 50 CL "t �F — I ( } 1.2p d " `.: RIM=1 0 1:+0 0 I -1- �_ " 14.0 M 1 TOP OF L h` 12" INV IN=108.25 a m TOP OF -r( 5: 12 INVs=108.33 `'' �� 12" INV ! TER �► 4" INV ;< PMANA MANAGEMENT AREA A �.: N ;I BOTTOM �llis— ER - (INFILTRATION POND 5P) :,,�q OTTOM (60) CULTEC 330XL CHAMBERSNSPECl 10>ED IMENT ERS=109.50TOP OF STONE=110.0;SEPARA SOS ,PQ OS RM ATER" TOP OF CHAMB 12 4 ,(i , 0 GAL/ON): 12" INV IN=108.50 T / (INLTRTI"0 I'Ot�ID.` 4P) 1= 12" INV OUT=108.50 1. CULTE. 3 0 L CHAMBERS109.25 �� A 1 o BOTTOM OF CHAMBERS=106.96 � ESOUT=109.00 , i a -, BOTTOM OF STONE=102.96 TOl? OF HAMBS _103.3 3 OF TANK=104.92 .� s fG a1:» �! INSPECTION PORTS TO FG 12, INV,INV IN )42 ". 1 v 4 f IRS �� .tt' T VNECT TO WAFER �`4 I Vs IN=102 7 PROPOSED SEDIMENT t �" �� �- -Il-a 8"x4"x8" TEE (2)ry8 IN\s OUT102 St3 & OIL SEPARATOR (SOS 12S) BOTTOM {S CHA BI:RS 0 7, r m T w -t , RIMs=107.00 (2,000 GALLON) f �3TTOM fOF STON 96 76 ; I, ii q ;0 � j TOP OF TAN =105.7 B 1 �; ii i ;, . . K 9 .;R,ROP: DM NfCT TO WATER INSPECTION RORT T f1NtSlGF1QE 1r T II Ir 12" INV IN= 104.20 1 IM=107.5 8:. c6"x8" TEE /` _ _ i !i, .�_ J 12" INV OUT=103 95 ; 10�1C!0 q U, 1= BOTTOM OF TANK 9 _ (2) 18 s!P w _ 12 NV ?0Q y, APPRO EF—'SOLI OVER GRATE X, Cg. OM f08 OP_! DMF- ., RI RIM-108.0 1 PLANS INV DljT-T 12" INVs=1 .IHDP�F�DRAI(y,; 1.0.6 F :W - Rftu1_ --� —• MH I� i2" RCP 1NV=100.73 = 6.73 i}g-------------- -� --- - 46 - -- ` 2 DP RIM D10 - _ _. . �;:;. - '•. _ �> RCP - RROP. DOUB LEG RA = --• - - -.. - - PROP. DMH TRIM 10.5 T - _--- o; RIMs=107.33 � S 12" iNV 101_z60 FROM` DMH _,� _ _ BBIn , IP gEWER 0IPI-", :12 .INVs OUL=1 3 c� $_ 15 b 12 INV S 101.0 FRAM UDRAI S -_ S Si. '" E1� S '; w36�' 'DETERMINED *U a � CONNECT 2"ATEMANHOLE E r- " o ��� -RAISE PA\ .,, n W/12 --- _ W---- =v Q RIM-S105.23 { �_ DURING. C. FIRS �; 0 2" +: _ 15 CIP INV=99 93 , C� 12, � :I-�E w -� " _. _ — 2� "WATECGATE�NR - Ct}NNECT TO WATER a ,s W/12"x4"x12" TEEEX DMH 10" o w/quw rovFR 'y � �,. =R•��rc .. "".,,,'.,�... ,....w..,.a r. .... .-�.._. .....,,,...- _ ... a..,....�....�.n.;...�......,. .,. •. .s,,. t +m '..e�- r � _ ,. ..... ="e 11 0; 12" INV OUT 0g�g \ x.; 12" 1 OUT-109 0 RIM s � \ I \ 2" MH i 1 RI 1 2 46 8'INV 108c08 -- - - I ` RIM=1 12.50 j SDR35 PV 1s 4"I NV.=108.16 SEWERS 1.0% 1'�: \\ 8"INV.=107.83 1 ! P�OP�QSED r STOR�AWATER (, moo. R G i 3`50 1 MAI�tA EMENT A ESA 6 \ RQP 1 HDP JIM t Co '(56) CULTE�:°33XL CRAM ERS-- -' 1 W IP RAP 0:t a S TOR OF c> ;OP OF CHAMB 1 v' 1;2" INV°1N YO_ 0 J, cn to . �\ w 0 4� INV�S IN 108 75; FROM�OOF `a' `_: NUS QU*' 1:66.4 '" C — :BOTT.OMF CHAMBERS—:1'06.46 I ,_ :_n- i cn I OTTOIyI �,O STONE=102.46-'" —i- u II s J+ ,I _ CP:—-f a ; ECMN ,C�t6llSH- E 1: i L A 1 1 p-_!L JL ta, [NV {}$,s45• `CI', 1 1 8"INV.=1'06.8 t II u tl li " ,� cQ Q. p_i� I 1 H ;NIA & �1ENT �p 1 N' 4" DOMESTIC u Ir„i H�. 1 5t =�� Q O _r FIRE '� n a a q p, _IS a' i': : 4 - ,� `rl • ' �� �� c _ ,l "1 9 I p II (I_II It I - - PROP S a s'INv.=107.6t °,a OUBLE� FA CB (10 II it q a D �Tz � . SMH 'UT RIM=112.00 4 INV 09: 8"INV.=1 07.30 r t— N' ' - � +114'S.' T - - RIM=112.95_ TO.1 (2) 8" INv'S=118.18` - - _ `' -_ •� � I�,dRt �- z 11A1T' 7 NO REFI(9D+€JLTRA ND 2P)`. i I y LlGHT Q - - -TOP 6F :g-TaE 110 25:_ P�zo F=C7F�AKABER Mrir T ARM L 12" INV IN 108.75 S,. � E� M H tr Wal ER/ W - _ III 07 82 G: EX DISH - aca' (2)-8" PVCs OUT 107.75 (To Prop bMH) _x_ V: WO " QPOSE . t� N12" RCP INV IN=101.43 BOTTOM' OF CHAMBERS=107.21 {� $ ' - "iNV. 1 '\ anrrnu nF cmwF=i ni 91 —r 3s: e . G S PVC EX CB G �: _ - l �/ RIM=131,66 P, v RCP INV = , ^ - RCP NV I RCPINV OUyl T . 1 : ::EX. DROP SMH o RIM=132.34 ;, i• -EX 8" PVC INV=12 �49 15" ' \ 18" RCP FIRE _ _ INV.=1 18_76 ALARM 1 - - MANIA( y c 0 \' (INFIL o ;} 32 , TOP TOP a • �, ` ` � ,: ' ,� �� � Born BOTTC INSPE EX DMH RI =124. 9 O 1 RCP INV IN=115.49 . /3G RCP INV OUT=115.49 ,ki� 8�FIQV 6" ,FIR[[ �1, 1 / N; �\ V00 p, Ln Z3 ? ' 89- -C NNE WA6 /8 x6 x6 TEE CbNNECT TO WATER 31. W/6"Wx611 TEE 6 CONNEC =1 .75 V � N W/8 x6 x8;,; TEE. r =10.55 11 0� J \` 35 �GY BC-11F EX. CB G 1 t3 i RIM=116.95 , 1-7 TK T6 � 1511 RCP INV-112.15 \P -� � NV - o CONNECT TxO12"ATEE � , ' r ♦_ PROP. _ at f -` : 1 pQp4 , • • � �� yVA���` `•✓' f ti �etff'�� yi ' at - n..M-•'"`♦ "�" - F �'�'' f.- `'�E �E E E `'' peE`�����i E r , e , I �f ' � � ". �, t Y .... .d E � �ram/ j •, r f.m " r. , ripw 97 ���' � ' ; E�r�� ~� � r`. aim � °' .• f ; . r ✓ +•, ��;. , + �.��s.• ! -:' •! �;E:-f`g ri` A•N`4� f �§+r-fear" ! � i' �' f E�f �avE' � f d ``t? tf•,� i 1 t i I , a, $ '••�µ°.. F '' � f r ���-d���w�er> t E^( ca d � �r scd t {^ I�I ® � � EE xt, c� ,<�ql, �yf � d ,�/�'c, ea y r�� v�F• f '� �` •.� } Y - s'�1� r E F f �d R � f�- E d,, E dd• d �• E `'. ' ;; � + EE!E cd d, .� rF f dE E�• r � EE E ` 'd�E�1E f �1 d YYE+°%d AF ,�. �r� � I ,,.. � yrr E.trfEEF.:E d�,,,,�EE 'd.F• - E�::zrEd �� dr�,. f ! ^,dd d /' e.y ,'''�' I' it ae n da , e n T DEMOLITION PLAN SHOWING CUTS O&'FILLS(+) PROPOSED APARTMENTS TRADERS VILLAGE "R.*-d or•!aw r n Pvituwot.OnlEyx 1 y© SPARAGES sam.YorooDRAWNG.C8.1 =- C On!nphdyyr°y gym.ai ®w.wN mued for varnw f J 'I SHEEP 120F 12 uu!t>t n.top pwdrq nwarueornmKaai srraomm,r ! 1 i }a Response to August 30,2018 Peer Review by NECEX 40 First Street/45 Traders Wayy September 5,2018 impervious surfaces to one acre or less; providing pool storage in the first chamber of 400 cubic feet per acre of impervious surface; making the permanent pool equal to 4 feet deep and providing removal covers that allow observation and s maintenance. } •R f • Extra water valve We have added a 12"water gate to the north-side of the connection from proposed Building 6 to the existing water main,see attached plan excerpt. • Sidewalk demo limits We have enlarged the demo limits to include the removal and repaving of the sidewalks along First Street and Traders Way,see reduced size copy attached. t r Should you have any additional questions,comments or concerns please do not hesitate to contact me or Peter Blaisdell by phone or email. Very Truly Yours, ` g r4 Richard L.Williams,P.E. Principal Cc:David Knowlton,City Engineer William M.Ross,P.E. Peter Lutts&Pavel Espinal . E i 3 j. t L! r. 12" INV IN=11/.20 /+ 12" INV OUT=116.95 R j BOTTOM OF TANK=112.87 r +1 iRVJS:117.65 � 12" INVs=113.10 �'`: 'I _ ' = PROP. SHALLOW DMH RIM=119.36 • 4 I r �' 12" INVa=116.00 �. 15 CdR GARAGIL 117.715 +116.5 ° I aPROPOSED STORMWATER �. PROP. SHALLOW DMH I MANAGEMENT AREA - RIM=115.5�� �' (INFILTRATION POND 7P) °` 4" INV IN=113.0 (72) CULTEC 330XL CHAMBERS 12" INVs=112.5 I` TOP OF STONE=116.25 TOP OF CHAMBERS=115.75 D' SEDIMENT � ;� 12" INV IN=114.75 12" INV OUT=113:50 OIL SE._. TOR (SOS 15S_. I BOTTOM OF CHAMBERS=113.21 RIMs=114.2' ,500 GALLON)' I BOTTOM OF STONE=109.21 TOP OF TANK :.79 ! INSPECTION PORTS TO FINISH GRADE 12" INV IN=110 20:" i .._ PROPOSED STORMWATER 12" INV OUT=109.95 - 110 jam, MANAGEMENT AREA BOTTOM OF TANK=105 87 16 (INFILTRATION POND 6P) -PROP. SHALLOW DMH I' (50) CULTEC 330XL CHAMBERS _ •RIM=114.0 I TOP OF STONE-114.50 �' 12" INV IN=108.25 ' m TOP OF CHAMBERS=114.0 12" INVs=108.33 l 12" INV IN=113.00 - -PROPOSED STORMWATER f' 4" INV OUT=113.67 `MANAGEMENT AREA {,. BOTTOM OF CHAMBERS=111.46 , (INFILTRATION POND 5P) ,` INSPECTION PORTS TO FINISH GRADE (60) CULTEC 330XL CHAMBERS '; _ J TOP OF STONE=110.0 1: _8"INV.=107.0± ,. TOP OF CHAMBERS=109.50 •12" INV IN=108.50 u. o 12" INV OUT=108.50 (r BOTTOM OF CHAMBERS=106.96 BOTTOM OF STONE=102.96 INSPECTION PORTS TO FG �It ` :_.PROPOSED SEDIMENT �. cH.-p-� & OIL SEPARATOR (SOS 12S) 511 yLy RIMs=107.00 (2,000 GALLON) TOP OF TANK=105.79 oU' N 12 INV IN= 104.20 PROP. DMH RIM=107.5 N�h i 12" INV OUT 103.95 (2) 8" INV'S=102.58 , !I°-,1 BOTTOM OF TANK=99 " i� 12 INVs=102.25 _ QM 108 -POOP. DMH RIM. 108.0 " 12 INVs=104.0 4RERF HDP ,I RIM=1 3 6J., DMH RCP INV=100.73 RIM=106.73 36" RCP INV=102.83 . 3 GRATE. ._ .:. •�;` . . - - - S -.`'�� r ... 15.. 0U5" GE # 1, WATER SM�H" - RAISE PAVED OVER DRAIN In'l TEE -� -, 1 MANHOLE TO FINISH GRADE �. RIM=105 23 DURING CONSTRUCTION ' �-= ---=W 15_ CIP INV=99 9'3 rn 12"-- I WA_. -,E W RO l6CATI0N 0 o ear (APP• ): V z 12" WATER Fa4 SMH G#ATEe a .. _CONNECT TO WATER 'i i cv n�au 15 CIP INV=99.69 , i NMING c -- RING cow: 265 ESSEX STREET,SUITE 1Q,P`O BOX 3g26 SALEM,.MA 01970 PH:978,741.7401-WWW.ENGINEERINGCORPORATiON.COM August 30,2- 8 .Ms.Amanda Chiancola. Staff Planner Office of'P.lan-ii ng and Community Developrrlent 120 Washington Street Salem,''MA 01.970 Re: City of Salem RFQ;R 501—, On-Call Civil Engineering Support Services;Task Order No. 36 Peer3Review Service's,40:First Street;and 45 Traders Way;Salem;MA .ear.Amdhda We are pleased'to support the Salem Planning Board with peer;review services for the above referenced project. We understand the project will be presented at your next September 6,201'8 meeting,we have Prepared.this addenda o our June 12;2Q 1.8 and July 17 2018 peer 'review letters.for your use at thaf meeting Project Understanding' • The developer'(PeterLuiz/Paval Espi 11 nal}proposes a redevelopment project(Traders Village)`at the current site of 40,First Street and 45 Traders Way: The project will uivolve construction of new buildings�..parking garages, and related site`work and utilities. • The City of Salem requests an.independent peer review of the proposed development plans and documentation including stgrinwa"ter management, drainage, and on=site,engineering uflity issues covered b,y'the Environrhental Impact Statement, • Included;in the peer review vv111 be considera"tion of existing and proposed;utilities, sewer separation and infiltration issues, water main capacity and water valve status;and adequacy of existing utilities o serve the project: Peer review,will not require compliance with requirements.ofthe Flood Hazard Overlay;Distrct special permit, 40 The City of Salem has xetairied a,traffic engineer.to review the'traffic access;egress; and site circulation issues as well as parking;,so those elements are not included a$part of this peer review. WATER RESOURCES BURIED INFRASTRUCTURE PUBLIC WORKS CONSTRUCTION ADMINISTRATION LANQ.DEVELOPMENT 1 r Project Understanding NECE prepared a peer review letter on June 12 2018;and a,second peer review letter dated July 5 2018: • Applicant prepared a response letter with additional information dated June 27, 2018 with a revised drainage report.and;revised set of'drawings: 6 Applicant prepared a second,response letter with additional information dated July 17,2018 with revision explanation and-revised drainage:calculations. • We met with applicant on Augusta 5,2018.� • Applicant prepared a third response letter°with additional information dated August 1 Z,2018 including a revised set of drawings with revision date 0:8/l5/18 and revision explanations and revisedArainage calculations: ReviewComments(06/12/18jetter) A Original Submittal Package Specific documents ye..v�ewed include a'Planned Unit bev opment Special Permit Application (3 pages), a Site Plan Review Application(3 pages);;permit cover letter,Project Narrative(2 pages),.Environmental Impact Statement(15 pages) S"tormwater Report:dated 2/28/18, Lighting `Plan(4 sheets),and;a set of Design'Drawings dated 3/27/1:8 (,10 sheets), Landscape Plan(5 p` s),June 272018p e r revi ew response letter and supporting documents,July ,17, 2018 peer. review response letter and supporting documents, and August 15, 2018 peer review response letter and.supporting documents: Existing Conditions Plans'—Sewer Drain Easement The plans appear to indicate a private utility easement crossing the project along the eastern property line. The project proposes to utilize the;sewer'pipe but not the drain pipe as part of this project.. Not clear on ownership, contributing catchment areas, or use restrictions on this easement or utilities that would impact the project: Status=Resolved,Applicant,provided eadditional'information n;06/27/18 letter. Watershed:Maps Watershed maps are;provided.to:delineate pre-and post-development drainage catchment areas. (C2.l `and C222) Basis for breaks between catchments`are not clear on existing conditions. drawings, including breaks between catchments�.1 S and 3 S and,limits of existing contributing area from shopping complex and roofs in 1 S.. Request:clarification that existing complex lot& and buildings do not contnhute drainage to site beyond delineated IS'. Existing catchment areas 4S.and SS appear to be mislabeled on plans versus the stormwater report,as are catchment 8S and,78 ; model should confird correct catchments are accounted for. Flow paths corresponding to the time of concentration(Tc)are indicated on mosVcatebrhent areas, but should be added to proposed 4S and building catchments:: Status=Resolved,Applicant provided additional information in 06/27/181etter. NEW ENGLAND civrr FavcnvEExuvG cozy. Page 3 of 9 r + Existing Conditions.Plans:Drainage The drainage infrastructure on First Street;is shown with incomplete connectivity, including a catch basin and manhole that do not iconnedt,jo closed;drainage on first street and"approximate" locatton of a catch basin and 36"dram pipe on the site; Since the project proposes to connect to City drainage n several locations, we,recommend the.connectivity b'complete in the vicinity of the propose.'d cbnnections.. Status Unresolved. Applicant provided.,addtional:information in:06/27/18 letter.but cannot confirm the connectivity of drainage on First$treetand.acknowledged that there appears,lo be two buried or paved over drain structures that will`require pipeline cleaning and CCTV inspection to locate antd excavation to raise:structures and confirm connectivity, A h pp cant has added a note:to the plans describing this work in 08/1711.8 submission. Recommend condition of approval that Applicant complete pipe and structure cleaning and CCTV inspecft'on to:confirm'dfain connectivity on First Street and Eubmit results and P g g p p ' p P revised "lans to En ineerin De artment rior to recei,t of foundation`ertnit. Proposed Grading and Drainage Existing contours are shown on existing condttion"s plan and watershed map C2.1, Proposed contours are shown on watershed map CI Neither plan shows both pre and post contours. Proposed Utility Plan(Sheet*of 11)provides gradesrfor castings but.no contours"or spot,grades Status=Resolved. Applicant provided additional information'and revised draings its • 07/17/18 and-08/17/18 submittals: w Site Plan Review Application:and Planned Unit Development Special Permit, Plans required to include: Location and dimensions of utilities; gas,telephone,communication; water, drainage, sewer;and other waste disposal;,external lighting; landscaping and screening; snow removal: _. p p g , p ( _ Plans do not identify locations of ro osed as tcle hone communication "or electric service and for lighting)utilities. Status Unresolved. Recommend condition of.approval,-that Applicant provide revised utility plans with. proposed utilities,including:gas,telephone,communication;.electric service and lighting; And gas meter and electric in aocations; prior to receipt of foundation permit. • Irrigation Plan An irngat on plan is not provided'on utility, drawings: Status Unresolved. Applicant has confirmed there,.will be irrgation;and it will be metered separately with appropriate backflow. 1lTE "ENGL AND CIVEL ENGINEERING;CORD, Page 3of9 ll ;Y Recommend condition of;'approval that Applicant provide revised utility pl'ais with irrigation piping, connection to City water.main,and backil prevention and inetering. prior to receipt offoundation permit: o Proposed Lighting Plans identify proposed exteior lighting;but do not identify the buried electric`lines toAhe lights or the buildings. Status=Unresolved. Recommend condition ofapproval that.Applicant provide revised;plans with locations of proposed transformers and buried electric utilities to serve Buildings and exterior lghts,- Existing Conditions Plans—Waterr and. :Sewer Existing conditions plans do not identify.the number;size,or location of existing-water mains on, _. Traders Way, and do not clarify the size of-the, main on First Street(1.2"or: 5"); :Existing sewer in utility easerent from;theahopping center does not include''invert'elevat ohs,with the upstream elevation labeled V6 h a"? and the downstream invert elevation labeled with"verify". It`is not clear how much of'the adjacent.commerciallresdential'complexes utilize the existing. sewer in the easement; so the available capacity is unknown: Status Resolved. Apphcani has collected,additional information in the field and incorporated into."revised plans dated 0,8/15/17. Demolition Plan A,demolition plan has not'been provided for review. While the demolition onsite is primarily limited to site work, it will be,useful to depict the proposed cut and fill areas,limits of tree removal onsite and along City right=of--way, and proposed work to City curbs and sidewalks for curb cuts: Status=..Parta(l Res A Lcant has rovidedadditonalnfoolved rmation;in the 07/17/18° and 68/17/18 submissions and has addednotes on 08%15/18 plans. Applicant to revise demolition plan (Sheet 12)to include the limits of curb and sidewalk work to`be removed and replaced;on First Street and Traders Way. Proposed Utilities- Sewer The plan proposes to utilize existing sewer manholes for connections on First;Street and Traders Way, and tapped connections on private sewer in the easement. Request additional,information on existing sewer size and slopes to confirm capacity(see Existing Conditions Plan—Water and Sewer.comment). Status=Resolved: Refer to previous comments. • Proposed Utilities Water The plan identifies connecting to existing City water mains at two locations on First Street and fy one location on Traders Way: The plans do not identi the locations of the:existing water mains NEW ENGLAND CIVIL ENGINEERING COIYP , Page 4 of 9 a 1 r on both streets or include connectivity of wafer mains with observed water valves. The.,plan identifies three tapping sleeves with-6 inch valves. The City prefers full bodied tee connections With triple'valves unless there are existing`operab`le valves inclose proximity to the point of connection.- Applicant has proposed to extend a 6 mch water nto the:'site at.three;locations,_and reduce to ay 4.4nch domestic service,connection for each.building. The City does:not all fire service and domestic service to share the same water.line without separate ahutoff valves;the plans do not 1. identify any valves on domestic or,f re sere Mt_'. feeds or at any junctions throughout,the$ite. The City requests Applicant consider looping water feed through the site connecting the First Street and Traders Way connections to improve isolation and.limit service interruptions in the future. Status=,Partially Resolved':. Applicant revise plans to include a looped:8-inch water,main to; erve the maority of the buildings and separate domestic and,:fire feeds for Building_G Applicant has incorporated.-tripie;gate connections on First;Street and Traders Way. Applicant to revise Sheet 5 to include another 12 mcli gate"to the East side of the Building 6 connections on First Street ao isolate°the project:from the rest of First.,Street • Proposed Utilities:'-Drainage. The design includes increased runoff to Traders Way;catchment 3 S includes discharge from 13,000 SF of rmpervious areas to Traders Way without being intercepted by edtch'basins within the project lunits,raisingcern aboushee'flwn toin the traveld'wayndapact fyo exstirig,drainage.at First Street intersection. Status .Resolved. Applicant has revised the alignment of the curb cuts and ,nt-an road on Traders Way'to reduce the.;runoff directed;to Traders;Way; Proposed Utilities -Drainage The design includes a limited :number of catch basins to 'serve large and fragmented parking lot It is difficult to:observe how the drainage from the larger parking lots Niih parking islands) will drain to single locations without spot grades, contours;and flow arrows if necessary. In addition,runoff received by catch basins may.exceed their capacity due to the large catchment, areas served (catchment 195,205, and 23S`for example each discharge 15,000 to 20,000 SF of impervious area.to single locations)and r- dundant catch'basins;the drainage system may become overwhelmed As stretched capacity is reduced due to trash and vegetation;and may result in surface flooding.or pending; Status=Resolved. Applicant has provided additional drainage calculations to demonsfrate the catch basins provide adequate capacity with 50% clogging to aceoue for vegetation blockage,and has revised the catch.basin details to include"open throat" curb inlets on catch'basins to provide additional un-modeled capacity to account for potential vegetation clogging. NEW E1VGY AND CI vIL ENG3NEERING CORPi Page5of5 Y • Proposed Utilities Gas Project narrative We ',natural gas as a fuel-source for the;buildi gs but gas piping is not identified on the plans: ;Status=Resolved.,"Refer to previous recommended condition of;approval Garage Drainage and Roof Drainage gr parking garages The garages do not includedra'a, or Plan includes several small at-grade ,ar oil/wafer separators,prior to connection to sanitary sewer. Status ResoledApplicant has.confirmed the proposed,open air garages do not meet the requirements:for covered garages and require oil/water separators per tho,,Plumbing,Cod'e. Revised plan(08/15/18)combines=buildigs3d4andi vedgagtgdnann r ae: Applicant has added an oil/water separator for the covered parking garage under'building:'/4 but has novprovided plumbing plan to demonstrate how drainage from:entire garage will be collected by the single discharge, Status'=Unresolveds _ Recommend condition of approval that the Applicant provide:a plumbing plan to demonstrate the number and location of floor drains and piping:'in�thg garage discharging to the oiUwater separator`and the location of vent piping for the separator in the building and submit it to Engineering Department; prior to.receiptof foundation;permit: Revised plan(0$/15/1;8)'includes six roof drain downspouts;three of which,discharge to_an. additional sub-surface infiltration system that was added to the plans; and three of which discharge directly to the wetlands iA rthout outlet protection tq,prevent scour and erosion. Status=Unresolved. Applicant i revise plans and include outlet protectiomfor all proposed roof drains that discharge to the wetlands or,on! rqqnd. Stornrwater management design require roof drainage from all buildings to be collected and discharged to,subsurface infiltration and detention systems., The majority of the.huild'ng identify a single roof drain,discharge point to collect the,runoff from the entire building;without a plumbing and;final;_roof plan it is not clear if.the entire roof drainage cari be collected at single points of:discharge as shown. Status Unresolved: Recommend condition of approval that the Applicant provide a plumlbing,plan with final architectural plans to,Engineering Dept:that demonstrate the entire roof drainage,can. be, collected and conveyed to the subsurface syste receipt of foundatio permi ms as shown on the civil drawings;'prior to' n t. NEW ENGLAND CIVIL ENGINEERING CORP: Page 6 of r �k Y Drainage Alteration Periit(Engineering Dept.) Project includes a numbei of cutand fill areas, including Proposed fills m excess of three vertical feet. Asa result,the project.requi%s a drainage alteration permit.from Salem Engineering Department. Status Resolved. Applicant to prepare lip- r,requesting permit with reference to 018/15/18 plans. • Stormwater Management;Permit:'(Planmng,Dept) Applicant's'Siormwater Report dated.February 28: 20l8 meets requirements of Stormwater. Management Permit: States=Resolved, Stormwater Management!Report;Drainage"Analysis New Drainage Outfalls Design includes.three new stormwater outfalls. Two of the outfalls discharge to a wetland resource area,zn one discharges above grade on First Street. These outfalls do not appear to provide 8Q%removal of total suspended solids (TSS)in accordance with the Mass Stormwater.Policy for new:development projects,as described in the Stormwater Report the outfalls;propose 446%TSS removal. The outfall that<.discharges to grade on First Street.provides the required treatment and TS;S removal,but f$40sitioned m a location that discharge must flow over sidewalk and roadway to reach the;modeled discharge location 4L;to.6L Status=.Resolved Applicant has revised plans to utilize different stormwater.treatment, devices with impr,.oved TSS:removal.on the two wetl"and outfalls,-;and has relocated the proposed First Street outfall to make connection to closed"drainage instead of discharge at sidewalk: Pre and Post..Runoff Design incorporates nine sub-surface infiltrate on systems to detain runoff and increase groundwater recharge Design"incorporates connections to the=City.drainage on First Street: pP Wage Analysis dated Jetne:27, Status-Resolved...Applicant has provided a revised.Drat 2018 and a su lement to the Drainage Analysis on July 1.7 and Augpst`.17;2018. Water Quality^'Design incorporates deep sump catch basins'and oil/sediment separators for pre= treatment prior to discharge to nine sub=surface infiltration systems. The Mass Stormwater Policy allows for infiltration if pre=treatment,provides 44%removal of total suspended solids (TSS). The treatment chain proposed does provide 44%:TSS removal;however.the proposed catch"basins are identified as"shallow CB W',and oil/sediment separa"tors to not match the configuration and design considerations of the Oit/Sediment Separators in the MassStormwatcr Handbook(V61ume,Z Chapter 2, Page 7), sped ifcally the discharge orifices m the1irst chamber and the inverted elbow discharge"n the second chamber.. NEW, ENGLAND OVIL FWGINEERING CORI': Page 7 ofi9 Status Resolved. Applicant has provided additional construction.details.demonstrating shallow Iasins have 446.0tsumps.and has confirmed the;sgparators meet MassStormwater' Policy requirements°for water quality structures'. Design incorporates eleven 1,500.g4llon oil/sediment separators of the same size,serving catchments of vanous.sizes. Plans provide two details for,the:same size"separator. Status=Resolved, •Applicant has deleted the-duplicate detail for the 1560 gallon tank and -has revised plans and details to show the size.of the..separator proposed in each location (1,500,2,00,0,and 2,500 gallons) as applicable: Design.includes a.hm'ited.number of catch basins to collect the runoff from the park ng.lots. The catchment areas served by some wof the catch basins is too large to provide adequate treatment? and TSS removal-per the'Mass Stormwatei Standards which recommend impervious areas b. lrnited'to 1/4 acre for each basin-and flows be restncted to less than 3 cubic feet per second. $,weral basms;serve much larger impervious areas, for,example the single double=grate catch basin is intended to serve a catchtnent area of over 26,000 sf;(over 20,000 sf impervious)and is predicted to convey flows of3.67 CFS during a 00 year storri , Statics-=Resolved: AppLcra'nt has provided additional drainage calculations to.demonstrate the catch basins provide adequate capacity.with 50'% CIO$" 9.1"gtor vegetation blockage,:and has revised the,catch basin details to include"open throat' curb inlets on catch basins to provide additional.un modeled capacity to account for potenttal vegetation clogging. Infiltration-Applicant has provided soil boringfpit information in four locations but has not provided sub-surface soil information for most of the.nine proposed.infiltration systems. Soil uiforrnation'prov.'ided identif es ledge 2-3' deep in three ofthe.four locations-and depth to groundwater is not identified: It appears likely that blastmgwll.be<requiied in most of the locations of proposed infiltration;eight of the nine units identify the bottom of the.system as stone,while one unif proposes the bottom°of the system "bro as ken ledge"; Status='Unresolved. Applicant to complete remaining sub-surface investigations. Recommend condition•of approval that.Applicant complete remaining;sub-surface investigations and submit results to City Engineer along with design changes;to configuration or location of sub.-surface storage and infiltration units; prior`to receipt of a foundation permit: Review Comments (07/05/181etter)• City Engineering Department Feedback The Salem City Engineer requests confirmation that.the existing collector sewers on Traders Way and First Street have adequate capacity acid condition to accept the peak flows generated from,the development. In addition to the previous requests for information about existng.pipe sizes and slopes, and"the service area and flows conveyed by sewer in the easement,the City"requests the, applicant confirm that there is adequate capacity in the • i NEW ENGI.AATd)CIVIL.ENGINEERING CORP. Page 8 of 9 existing sewer during peak flows tO receive the peak hour flows io be:generated by the pr"oposed development. The City also requests the.conditionbf the pipe to receive additional flows be confumed through closed circuit televised pipeline inspection from the points of proposed connection'to.the downstream,interceptor sewer atlVlooney,and Highland Avenue: Status=Unresolved. Applicant to complete pipeline cleaning and CCTV inspection and:submit resulting report to Engineering Department, Recommend condition of approval that can complete,cleaning and CCTV inspection of City sewers from points of connection on'Tradef-Way and First Street to the tnterceptor sewer.at.Mooney and Highland Avenue,submit"report and videos to City Engineer,and address capacity,condition,;:or infiltration issues identified in this line as part of fhe project as drected'by the City Engineer; prior to receipt of:a building permit; • Wetland L�ipacts The City requests additional information to,consider potential impacts to the wetland resource area. The applicant has provided pre and post development flow rate projections for flows leaving the project site The,City requests the Apphcarit provide additional data relative to the pre and post-development flows entering the wetland resource area within the projec"t site,,including both peak flows and total.volume for the design storms: In addition, the City requests additional information about,the dog park proposed on the project site g p g? adjacent to the wetland resource.area,;melud n s of ages and:drainage patterns and operations acid maintenance plan to<<prevent�dog waste or runoff from entering the resource area. _ y Status=Partially Resolved. Applicant has:revised the configuration of the dog park with curbing and grad ngto:minimiie any potenhal.impact to wetland resource. Applicant.to provide narrative t'o Planning Dept. regarding protection/enhancement of wetland resource and calculations on pre and post-development flows entering the Wetland,resource. if you have an require _ y y questions or re uare additional information,please do.not hesitate to contact me at any time on my celhphone,at 978.767-5415'or at thy;S'alem office at 978=741-740i. Sincerely, , William M Ross,P.E. Project Manager/Principal Engineer New England Civil Engineering Corp: Ce:David Knowlton, City Engineer ClieriYs/Salem/Traderswayl080320I8rep ieiv:letter NEW ENGY VD CYVTL ENGI NEERING.C®RP. Page 9 of 9 Project file: SALE-0036 WILLIAMS SPARAGES August 17,2018 cc ENGINEERS . PLANNERS .SURVEYORS Ms.Amanda Chiancola, Staff Planner TIRECEIVED Office of Planning and Community.Development S 120 Washington Street AUG 2® 201� Salem,MA 01970 H P`' DEPT. OF PLANNING & RE: 40 First Street/45 Traders Way, Salem,MA;Peter Lutts&Paval EspinatI 1) D Ev E LO P M E N T Response to Peer Review Comments by New England Civil Engineering Corp. Dear Amanda, The purpose of this letter is to inform the Board that we have responded to the original comments received by New England Civil Engineering Corp.(NECE)with a letter dated June 271,2018 and two(2)supplemental packets of information to NECE in Memorandums dated July 17,2018 and August 17,2018.We have also included the site plans revised through August 15,2018 for your review,see attached. We met with Mr.Ross at NECE on August 15,2018 to discuss the revisions and we look forward to presenting the modifications in greater detail at the next Planning Board hearing scheduled for September 6,2018. • Should you have any additional questions,comments or concerns please do not hesitate to contact Rich Williams or me by phone or email. Very Truly Yours, Peter M.Blaisdell,Jr.,P.E.,P.L.S. Project Engineer Cc:David Knowlton,City Engineer William M.Ross,P.E. Peter Lutts&Pavel Espinal y • 189 North Main Street, Suite 101 • Middleton; MA 01949 • Tel: (978) 539-8088 • www.wsengineers.com e m o r a n d u m WILLIAMS & SPARAGES ENGINEERS Y PLANNERS SURVEYORS C T S To: William M. Ross, New England Civil Engineering Corp. From: Richard L. Williams, P.E. Date: August 17, 2018 Subject: Fist Street/Traders Way Water & Sewer demand .job Number: SALE-0036 Based on the expected bedroom count,and retail space for the First Street/Traders Way project,we expect the Sewer&Water demand to be as follows: SEWER Residential flow: 375±bedrooms @ 100 GPM: =41,250 GPD Commercial flow: 5,000 s.f.@ 50GPD/1000 s.f. =250 GPD Total peak flow(peaking factor of 5)= 0.32 CFS WATER- Total demand for residential and commercial flow is 41,500 GPD Estimated landscape irrigation flow during peak months is 4,500 GPD 189 North Main Street, Suite 101 • Middleton, MA 0194.9 • Tel: (978) 539-8088 • www.wsengineers.com WILLIAMS SPARAGES • Memorandum KAMM . To: William Ross, P.E. T s From: Peter M. Blaisdell,Jr., P.E., P.L.S. Date: August 17, 2018 Subject: Fist Street/Traders Way 2^d Supplemental Information Package Project Number: SALE-0036 Bill, Here is a summary of the changes to the site plan set and supplemental calculations that have been performed since our meeting on August 15th,2018 for your review.Rich Williams has also calculated the water &sewer demand as requested and is attached under separate cover. 1. A revision date of August 15,2018 has been added to all 12 sheets,in the revision block it will state"No changes to this sheet"if there were no revisions as a result of our meeting. 2. We have added a note that the existing paved walk along Traders Way and First street is to be repaved on sheet 4 of 12. 3. The dog park has been relocated slightly,calls for a curbing to contain any pet waste and we . have amended the proposed grade and shown a walkway leading up to the proposed gate on sheet 4 of 12. 4. We have added a note that the water connections to the mains in Traders Way and First Street will have triple gates installed on sheet 5 of 12. 5. We have looped the water from Traders Way to the connection on First Street on sheet 5 of 12. 6. We have added a note"Raise paved over drain manhole to finish-grade during construction' for the buried structure we discussed located at the southeast property coiner on First Street on sheet 5 of 12. 7. The detail of the shallow catch basin has been modified to include a granite throat curb inlet to increase capacity on sheet 9 of 12. 8. The details for the precast double grate catch basin and precast catch basin have been modified to include a granite throat curb inlet to increase capacity on sheet 10 of 12. 9. We have included the length and area of the existing sidewalk removal at the proposed entrances to First Street and Traders way on sheet 12 of 12. 10. We have added a note to"Determine location/condition of drain pipe"at the proposed end of pipe from the original layout of First Street on the south side of Building 5 on sheet 12 of 12. 11. We have added a note to"Clean sediment from manhole to determine function'for the structure located at the proposed First Street entrance on sheet 12 of 12. 12. We have re-calculated the catch basin grate capacities assuming 50% dogging as requested at our meeting,and,they are attached here for your review. Please let me know if you have any questions. •Peter 2- �r, , wi®� ... .s Pam' - ~• {.,mot' '4q....,..-. . 10 e1 --- — — --- ;- rV GRATE OPENING RATIO i 1 6 P-1.7/8-4 0.8 — P-1-7/6 0.9 5 P-1-1/8 0.6 "� I 4 Reliculine 0.8 _ o- h Curved vant 0.35 rO A, (b 30° lilt-bar 0.34 0)0 3 . • Ttattd ' 2 i ' i 6 I � 1 0.6 0.6 �. 0.5 CURB 0.4 T W 0.3 5 p-— L --i d ;O '' 0.2 A=CLEAR OPENING AREA P= 2W+ L (WITH CURB) •P =2(W+L) (WITHOUT CURB) 0.1 I 2 3 .4 5 6 8 10 20 30 40 5^0 60 60 100 DIZCHME Q (FT 3/sl dam/®/p CHART 11. Grate inlet capacity in sump conditions. Vr 0. may, L ®• ' f\NAV,-- QT- okwu ?N\)4D � 71 CA 0 �c -.1100C rr,'f7( j1 � I `ACCv��`•f_..:!..ti"�e pig!` � �` t ��({.1 Io RAT QPENING RATIO I ; Q i 6 P-1-7/8-4 0.8 — — P-1-7/6 0.9 5 P-1-1/8 0.6 ° ! 4 Reticuline 0.8 Cutvid vane 0.35 �O 0 30' tilt-bar 0.34_ 0)a 3 • Tested 2 I I � t 0.8 0.6 •. 0.5 CURB 0.4 W 0.3 , 1 -- L --1 0 A=CLEAR OPENING AREA P = 2W+ L (WITH CURB) •P =2(W+L) (WITHOUT CURB) 0.1 1 2 3 4 .5 6 8 10 20 30 40 50 60 80 100 DIUMME a (FT 3iai 50 13 0/4. � ��. pt CHART 11. Grate inlet capacity in sump conditions. 4 0.IblD < ®.So 71 r 10 8 ' 1--i--- — — -- ------ - -i— GRATE OPENING RAT IQ ( ti 6 P-1-7/8-4 0.8 — P-1-7/6 0.9 Q' 5 P-1-1/8 0.6 "� I 4 Reticuline 0.8 —_ a �o • Curved vane 0:35 m 30° filt-bar 0.34 3 • Tested - 2 7 R i F 1 I t 0.6 0.6 0.5 CURB 7 0.4 �' = I . F(. W d I--- L - 0.2 A=CLEAR OPENING AREA ar- �� P= 2W + L (WITH CURB) •P =2(W+L) (WITHOUT CURB) 0.1 1 2 3 4 5 6 8 10 20 30 40 50 60 8'0 100 INSCHME a (FT 3/sl 0 fie® �/•'e b CHART 11. Grate inlet capacity in sump conditions. a �Ae C --12.. 'N(A►.1uP,u 0,5, D.o,-'" ®.I's o< ®.so 71 jz t C.A L,s°'�. ,off "••,.✓' e — - - - GRATE OPENING RATIO + ti Q 6 P-1.7/8-4 .0.8 P-1-7/8. 0.9 5 P-1-1/8 0.6 "� I 4 Reficuline 0.8 Curved vane 0.35 0 30° fill-bar 0-34 °j o 3 Tested 2 I — i ' 7 • i { � 0.8 0.5 CURB 0.4 T 3 � W 0.3 ? A 0.2 A=CLEAR OPENING AREA. �} P = 2 W + L (WITH CURB) -P =2(W+L) (WITHOUT CURB) 0.1 1 2 3 4 5 6 8 10 20 30 40 50 60 80 100 DISCHAME a (FT 3/s1 ® �O CHART 11. Grate inlet capacity in sump conditions. OS - z Mew UA u 71 ✓a�a����". �,:a`,'_/.'e c,.: I �--��, "�`"��.-�'"`�.- �`^`Ir J 11(i�,�1i 70, e 1 GRATE OPENING RATIO I rV 6 P-1-7/8-4 0.8 P-1-7/8 0.9 5 P-1-I/8 0.6 i Reficuline 0.8. 4 v, • Curved vane 0.35 300 tilt-bar 0.34, 0OP0 3 • Tested 2 i F I $ 0.8 0.6 LF 0.5 CURB 7 0.4 Q I 0.3 ? a 4 r-- L --, 0.2 A=CLEAR OPENING AREA P= 2W+ L (WITH CURB) •P =2(W+L) (WITHOUT CURB) 0.1 1 2 3 4 5 6 8 10 20 30 40 50 60 80 100 DISCH ME Q (FT 3/S) CHART 11. Grate inlet capacity in sump conditions. 71 50 to O o i I � 8 RAT OPENING RATIO ti 1 6 P-1-7/8-4 0.8 P-1-7/8 0.9 5 P-1-1/8 0.6 Q ti ,� 1 Reliculine 0.8 4 v� Curved vane 0.35 to 300 tilt-bar 0.34 0� 3 0 • Tested I V E i I l 0.8 0.6 - 0.5 CURB 7 • 0.4 Q 1 W 0.3 6 L — 1 0.2 A=CLEAR OPENING AREA P= 2W+ L (WITH CURB) -P=2(W+L) (WITHOUT CURB) 0.1 1 2 3 4 5 6 8 10 20 30 40 50 60 80 100 INSCHME a (FT 3/3) (J O CHART 11. Grate inlet capacity in sump conditions. 0. 60 71 WILLIAMS r & SPARAGES Memoandum ENGINEERS . PLMNERS i SURVEYORS T To: Richard Williams, P.E. s From: Peter M. Blaisdell,Jr., P.E., P.L.S. RECEIVED, . Date: July 17, 2018 AUG 20 2010 Subject: Fist Street/Traders Way DEPT. OF PLANNING & COMMUNITY DEVELOPMENT Explanation of Revisions/Calculations made in response to NECE comments Job Number: SALE-0036 Rich, Here is a summary of the changes and calculations that have been performed since the June 27th response letter to NECE and are reflected on the June 29th Plan Set with attachments 1. A cuts and fills have been added to sheet 12 of the set and a volume report was generated using 2 0 surface volumes 2. A Demolition Plan has been added as sheet 12 which shows limit of clearing,silt fence,street openings for water and sewer. 3. A revised utility plan was generated that shows an updated water line system and separates the 4" and 6" lines with their own shutoff valves and eliminated tapping sleeves and gates. 4. We have a revised watershed map based on the realignment of the driveways and openings 5. A drainage capacity analysis was performed on all of the proposed catch basins using a nomograph,Chart 11 of the HEC-12 US DOT manual for sump conditions and the Federal Highway Administrations Hydraulic Toolbox version 4.2,see attached. 6. We have added an MDC Gas Trap for the floor drains of proposed building 3/4 7. We will be requesting a Drainage Alteration Permit from the Salem Engineering Department,I do not have a copy of the permit application form yet. 8. See revised TSS removal calcs and Weighted Average demonstrating that the project will remove in excess of 80% 9. A detail of a shallow catch basin with a 4' sump has been added to the plans 10..Updated details of the Sediment and Oil Separator units for 1500,2000&2500 gallons have been added. 11. Added HDPE underdrain atbottom of the hill above First Street 12. Revised Cultec details for depth and size of stone beneath systems 13. Increase size of sewer line to 8" diameter 14. Added Clay Collars to drain lines for Anti Seep Please let me know if you have any questions. "eter PROJECT NUMBER Cut_Fill(180712) .txt Volume Report Comparing Grid: P:\SALE-0036(First Street & Trader's Way)\Drawings\EXISTING.grd and Grid: P:\SALE-0036(First Street & Trader's Way) \Drawings\Proposed.grd Grid corner locations: 6309.58,5521.25 to 7319.58,6471.25 Grid resolution X: 101, Y: 95 Grid cell size X: 10.00, Y: 10.00 Area in Cut : 174,567.8 S.F., 4.01 Acres Area in Fill: 154, 644.7 S.F. , 3.55 Acres Total inclusion area: 329,212.5 S.F. , 7.56 Acres Cut to Fill ratio: 2.16 Average Cut Depth: 6.16 Average Fill Depth: 3.21 Max Cut Depth: 16.77 Max Fill Depth: 11.56 Cut (C.Y.) / Area (acres) : 5273.46 Fill (C.Y. ) / Area (acres) : 2435.86 Cut volume: 1,076,087.5 C.F., 39,855.09 C.Y. �� C.N Fill volume: 497,055.2 C.F., 18,409.45 C.Y. vow C •� v Page 1 Sediment & Oil Separator (SOS) Sizing Calculations — DEP Criteria • Limit the contributing area to 1.0 acre or less or impervious cover • Provide pool storage in the first chamber to accommodate the required water quality volume or 400 cu. Ft. per acre of impervious surface • Water quality for the project development will be improved through the use of nine (9) Sediment & Oil Separator Units varying in sizes from 1,500 gallon to 2,500 gallon as shown in the calculations found below SOS 9S Impervious Areas= 16,652 s.f. =0.382 Acres(Roof not included) 0.382 Acres< 1.0 Acres; Okay 400 cu. Ft./Acre x 0.382 Acre= 152.8 cu. Ft(Volume Required in First Chamber) 152.8 cu. Ft.x 7.48 gallons/cu. Ft. = 1,143 gallons;Therefore use a 2,500 gallon Tank SOS IOS Impervious Areas= 11,617 s.f. 0.267 Acres(Roof not included) 0.267 Acres< 1.0 Acres; Okay 400 cu. Ft./Acre x 0.267 Acre = 106.8 cu. Ft(Volume Required in First Chamber) 106.8 cu. Ft.x 7.48 gallons/cu. Ft. =799 gallons;Therefore use a 1,500 gallon Tank SOS 12S Impervious Areas= 14,148 s.f. =0.325 Acres (Roof not included) 0.325 Acres< 1.0 Acres;Okay 400 cu. Ft./Acre x 0.325 Acre= 129.9 cu. Ft(Volume Required in First Chamber) 129.9 cu. Ft. x 7.48 gallons/cu. Ft. =972 gallons;Therefore use a 2,000 gallon Tank SOS 15S Impervious Areas= 16,431 s.f. =0.377 Acres(Roof not included) 0.377 Acres< 1.0 Acres; Okay 400 cu. Ft./Acre x 0.377 Acre = 150.9 cu. Ft(Volume Required in First Chamber) 150.9 cu. Ft. x 7.48 gallons/cu. Ft. = 1,129 gallons;Therefore use a 2,500 gallon Tank SOS 18S Impervious Areas=8,105 s.f. =0.186 Acres (Roof not included) 0.186 Acres< 1.0 Acres;Okay 400 cu. Ft./Acre x 0.186 Acre=74.4 cu. Ft(Volume Required in First Chamber) 74.4 cu. Ft.x 7.48 gallons/cu. Ft. =557 gallons;Therefore use a 1,500 gallon Tank SOS 21S Impervious Areas=2,830 s.f. =0.065 Acres(Roof not included) 0.065 Acres< 1.0 Acres; Okay 400 cu. Ft./Acre x 0.065 Acre=26.0 cu. Ft(Volume Required in First Chamber) 26.0 cu. Ft.x 7.48 gallons/cu. Ft.= 194 gallons;Therefore use a 1,500 gallon Tank SOS 16S&22S Impervious Areas= 6,057 s.f.=0.139 Acres(Roof not included) 0.139 Acres< 1.0 Acres; Okay 400 cu. Ft./Acre x 0.139 Acre=55.6 cu. Ft(Volume Required in First Chamber) 55.6 cu. Ft.x 7.48 gallons/cu. Ft. =416 gallons;Therefore use a 1,500 gallon Tank SOS 23S Impervious Areas=9,572 s.f. =0.220 Acres(Roof not included) 0.220 Acres< 1.0 Acres; Okay 400 cu. Ft./Acre x 0.220 Acre=88.0 cu. Ft(Volume Required in First Chamber) 88.0 cu. Ft.x 7.48 gallons/cu. Ft. = 658 gallons;Therefore use a 1,500 gallon Tank SOS 19S Impervious Areas= 13,367 s.f. =0.307 Acres (Roof not included) t r 0.307 Acres< 1.0 Acres; Okay 400 cu. Ft./Acre x 0.307 Acre= 122.7 cu. Ft(Volume Required in First Chamber) 122.7 cu. Ft. x 7.48 gallons/cu. Ft. =918 gallons;Therefore use a 2,000 gallon Tank ` II PROJECT NO.'Shu=—Cz>--56 �1 r� ,:WILLIAMS 189 North Main Street, Suite 101 V V SPARAGES Middleton, MA 01949 ENCNEERS I KMINM SURVEYOR.' (978) 539-8088 Office T (978) 539 8200 Fax s poor \jo� a ,, www.wsengineers.com S' tA2154 TES: 5s 20 2 �� �q► .. L -► s 9 . 1oS j 85 1 S>_. . It S : �4 The �. _. o ► v : _............. 25 ..... . - 0 aSG�. ;Zo2a3 2�s + + <2�� CJ®® - t Stormceptor (SVV-'O!rV— -7s; - Brief Stormeeptor Sizing Report -1 0111 s 4x ; . Proje t Name First Street/Traders Way oectNu eC SALE-0036 Salem � t�tel 1'r�o ce Massachusetts Coun�y United States of America te a 7/15/2018 IRV ame �LL :� Peter Blaisdell `{ ompany Williams&Sparages 978-539-8088 Y Phone �; pblaisdell@wsengineers.com email NIT", Stormwater Treatment Recommendation The recommended Stormceptor Model(s)which achieve or exceed the user defined water quality objective for each site within the project are listed in the below Sizing Summary table. _ PRA R Q 80 g 99 STC 450i The recommended Stormceptor Model achieves the water quality objectives based on the selected inputs, historical rainfall records and selected particle size distribution. Stormceptor Model %TSS Removal Provided v 1 STC 900 99 �►'�['� STC 1200 99 CO VAL STC 1800 100 STC 2400 100 STC 3600 100 STC 4800 100 STC 6000 100 STC 7200 100 STC 11000 100 STC 13000 100 STC 16000 100 StormceptorMAX Custom Stormceptor Brief Sizing Report—Page.1 of 2 Stor mcc to e MA�,�M - Ps- s �. ems: .?aa�ti-ti ,.�ree� .ac' . .F`�a,< ' +.e...,.,. 80.0 - ofa Area ac ss 0.53 � ) m erviousness o 0.6 un �i ��me p re Flo v� v_ atll Ca tr�Volume f � Coe eF1Q RafCF 3.23 on#dame BOSTON WSFO AP �: ��--�-� � � � lA►f�`�Q�raiity�Fto -Rafe��CF�� fate] ,rot ce Massachusetts Statlh 1 # € 0770 Ufa e a�ft �h y�e fs 58 LatifudE 42°21'38"N 0.000 0.000 71°0'38"W g _ € PRIME �z ARM g ;` �or IMIN 3• y " EcT, s rR IMM 'lie �efribuffn 20.0 20.0 1.30 60.0 20.0 1.80 • 150.0 20.0 2.20 400.0 20.0 2.65 2000.0 20.0 2.65 •Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor,which uses the EPA Rainfall and Runoff modules. •Design estimates listed are only representative of specific project requirements based on total suspended solids(TSS)removal defined by the selected PSD,and based on stable site conditions only,after construction is completed., •For submerged applications or sites specific to spill control, please contact your local Stormceptor representative for further design assistance. For Stormceptor Specifications and Drawings Please Visit: hftp://www.imbriumsystems.com/technical-specifications Stormceptor Brief Sizing Report-Page 2 of 2 Stormceptore 66,&C W- 120S rna�rnu„ Brief t r ee tot° Sizing Report - itStreet/Traders Way y -. INE&ct Name 5� First Street/Traders Way ON"ect�Tl+ mber SALE-0036 Grty� Salem pz� t a ro nce Massachusetts you t United States of America x ate 7/15/2018 Name Peter Blaisdell „y. � ompany, Williams&Sparages S w,y�� 978-539-8088ME �Phn z� M' pblaisdell@wsengineers.com Stormwater Treatment Recommendation The recommended Stormceptor Model(s)which achieve or exceed the user defined water quality objective for each site within the project are listed in the below Sizing Summary table. F First Street/Traders Way :r IIY a . s 80 _ 100 Vd STC 450i - The recommended Stormceptor Model achieves the water quality objectives based on,the selected inputs, historical rainfall records and selected particle size distribution. Stormceptor Model %TSS Removal Provided STC 900 100 "' STC 1200 100 'STC 1800 -100 STC 2400 100 STC 3600 100 STC 4800 100 STC 6000 100 STC 7200 100 STC 11000 100 STC 13000 100 STC 16000 100 StormceptorMAX Custom Stormceptor Brief Sizing Report—Page 1 of 2 Stormceptor- mh,.r So- y Cbtal rea{acres 0.43 �SSR�moual(�a) 80.0 r � . �. �mpemtagae Ste%s 0.5 U�nOff�OlUf17eap feo�a s S aflc�n��me BOSTON WSFO APk Ca�iyelFiow tteGF S 2.66 Sfa e/P o)rin e, Massachusetts „ „ 0770 e 58 to a e mac !�ha 9e� w� L a it de 42°21'38"N 0.000 0.000 Long tad - 71°0'38"W - I � rttc�e�l�lanaeter � _ strlb tlOi� �- Spec fic� rave ' 20.0 20.0 1.30 60.0 20.0 1.80 150.0 20.0 2.20 400.0 20.0 2.65 2000.0 20.0 2.65 •Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor,which uses the EPA Rainfall and Runoff modules. •Design estimates listed are only representative of specific project requirements based on total suspended solids(TSS)removal defined by the selected PSD,and based on stable site conditions,only,after construction is completed. •For submerged applications or sites specific to spill control, please contact your local Stormceptor representative for further design assistance. For Stormceptor Specifications and Drawings Please Visit: http://www.imbriumsystems.com/technical-specifications Stormceptor Brief Sizing Report-Page 2 of 2 INSTRUCW: 1. Sheet is nonautomated. Print sheet and complete using hand calculations. Column A and B: See MassDEP Structural BMP Table Non-automated:Mar.4,2008 2.The calculations must be completed using the Column Headings specified in g p Chart and Not the Excel Column Headings 3.To complete Chart Column D, multiple Column B value within Row x Column C value within Row 4.To complete Chart Column E value, subtract Column D value within Row from Column C within Row 5.Total TSS Removal =Sum All Values in Column D Location 6-W A B C D E TSS Removal Starting TSS Amount Remaining BMP' Rate' Load* Removed B*C Load C-D ®1�S >� F e'..ae..- A8X i 3Z3' a. �F ✓a' S ., vY isPa fr, z, v+ Y 1.00 o O m g� a r' O �r � a�. a,r � sd pK d„� eft� „z�.'° � ,.� �� '� z � v t Separate Form Needs to be Completed for Each Total TSS Removal = outlet or BMP Train Project i". D! :C" 3 if� Prepared By E *Equals remaining load from previous BMP (E) Date: which enters the BMP Non-automated TSS Calculation Sheet must be used if Proprietary BMP Proposed 1. From MassDEP Stormwater Handbook Vol. 1 Mass.Dept. of Environmental Protection } 10 8 RAT OPENING RATIO I � 6 P-1-7/8-4 0.8 P-1-7/8 0.9 5 P-1-1/8 0.6 Q I A,4 Reticuline 0.8 ° q Curved vane 0.35 rO m 30° lilt-bar 0.34 �p 3 i• Tested i 2 i ` Q i F 1 0.8 0.6 0.5 CURB 0.4 '� W 1 o I 0.3 Q�. A 0 1 5 ham— L 6 O 0.21 A=CLEAR OPENING AREA P = 2W+ L (WITH CURB) •P =2(W+L) (WITHOUT CURB) 0.1 1 2 3 4 5 6 8 10 20 30 40 50 60 80 100 CISCHME a IFT 3/3) CHART 11. Grate inlet capacity in sump conditions. 71 I a\Je ('Y' ©r- C�% 10 I I B GRATE ry OPENING RATIO 6 P-1-7/8-4 0.8 P-1-7/8 0.9 5 P-1-I/8 0.6 4 Reliculine 0.8 h Curved vom 0.35 �O A, 30° tilt-Dar 0.34 00)a 3 • Tested 2 i Q i F 1 49 I 0.8 0.6 0.5 CURB r 0.4 W i 0 0.3 Q-. A 5 L 6 0.2 A=CLEAR OPENING AREA P = 2W+ L (WITH CURB) •P =2(W+L) (WITHOUT CURB) 0.1 I 2 3 4 5 6 8 10 20 30 40 50 60 80 100 INSCUME a (FT 3ia1 CHART 11. Grate inlet capacity in sump conditions. A A.. v Nth kg 71 G �s4c, k os l O® �-f t ( 7l:= 21 z , 10 I I 8 rV GRATE OPENING RATIO 6 P-1-7/8-4 0.8 P-1-7/8 0.9 5 ITP-1-1/8 0.6 V- ,,) 4Reticuline 0.8Curved vane 0.35 � 30° tilt-bar 0.34 . °jO 3 Tested 2 Q i F I , t I 0.8 0.6 0.5 CURB 7 0.4 Q 0.3 T a 0 1 5 �--- L --1 0 0 A=CLEAR OPENING AREA CI rD ��01 Pn 2W + L (WITH CURB) •P =2(W+L) (WITHOUT CURB) OA I 2 3 4 5 6 8 10 20 30 40 50 60 80 100 CISCHME a (FT 3/E) CHART 11. Grate inlet capacity in sump conditions. ��,�C•.-12 1vtP��1 Val. V.5. �•���"` � l�.w, �. M fit•-� �� - 71 C 16 - No --r�0W1 10 "mac 8 I I RAT OPENINGrV RATIO i I 1 6 P-1-7/8-4 0.8 P-1-7/8 0.9 P' 5 P-1-1/8 0.6 1 4 Reticuline 0.8 a h Curved vane 0.35 rO ^ O 30° tilt-bar 0.34 05 3 • Tested 2 qM it 0.8 06 0.5 CURB 7- 0.4 Q b Q W 0.3 9 a � h � 17— 1 r--- L --{ 0 0.2 A=CLEAR OPENING AREA P = 2W + L (WITH CURB) y1 1�✓ -P =2(W+L) (WITHOUT CURB) C% 0.1 1 2 3 4 5 6 8 10 20 30 40 50 60 80 100 INSCHME . Q (FT 3/3) CHART 11. Grate inlet capacity in sump conditions. ��,-�Z ���U�l�. V.S. �•C�:`T"' 71 goo y�. Q✓ c: Io 8 GRATEQPENING RATIO ti I 6 P-1-7/8-4 0.8 P-1-7/8 0.9 i 5 P-1-I/8 0.6 v ti ti 4 Reficuline 0.6 a h • Curved vane 0.35 ro 30° tilt-bar 0.34 Ca 0 o 3 • Tested 2 i i 1 t I 0.8 0.6 0.5 CURB T 0.4 �� I W 0.3 Q a1b �7 1 L —+ 0.2 A=CLEAR OPENING AREA P= 2W + L (WITH CURB) •P =2(W+L) (WITHOUT CURB) 0.1 1 2 3 4 5 6 8 10 20 30 40 50 60 80 100 cISCUME a (FT 3/S) CHART 1 1'. Grate inlet capacity in sump conditions. t : e kg 71 1 0 '"�-�G'✓ �.^ sue+ O 8 RAT OPENING RATIO `V I P-1-7/8 0.9 5 P-1-1/8 0.6 � Q' ti 4 Reticuline 0.8 a` h • Curved vane 0.35 �0 3 30° tilt-bar 0.34 CO0� 0 • Tested 2 i I t I 0.8 0.6 0.5 CURB 0.4 T W 0.3 17- L 0.2 A=CLEAR OPENING AREA P= 2W + L (WITH CURB) P =2(W+L) (WITHOUT CURB) 0.1 1 1 1 1 . 1 2 3 4 5 6 8 10 20 30 40 50 60 80, 100 DItQII ME Q (FT 3/3) CHART 11. Grate inlet capacity in sump conditions. `S � k9 71 Hydraulic Analysis Report • Project Data J � Project Title: SALE-0036 First Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis Notes: Subcatchment 23S Gutter Input Parameters Longitudinal Slope of Road: 0.0140 ft/ft Cross-Slope of Pavement:0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 9.3560 ft Gutter Result Parameters • Design Flow: 2.5300 cfs Gutter Depression: 0.0000 in Area of Flow: 0.8754 ft^2 Eo (Gutter Flow to Total Flow): 0.4738 Gutter Depth at Curb: 2.2454 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow:2.0100 cfs Bypass Flow: 0.5200 cfs Approach Velocity: 2.8903 ft/s Splash-over Velocity: 5.9184 ft/s Efficiency. 0.7945 Project Data Hydraulic Analysis Report Project Title: SALE-0036 First Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 2 Notes: Subcatchment 23S (Single Catch Basin for Bypass of double grate CB) Gutter Input Parameters Longitudinal Slope of Road: 0.0140 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 5.1692 ft Gutter Result Parameters Design Flow: 0.5200 cfs Gutter Depression: 0.0000 in Area of Flow: 0.2672 ft^2 Eo (Gutter Flow to Total Flow): 0.7292 Gutter Depth at Curb: 1.2406 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 2.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 0.4025 cfs Bypass Flow: 0.1175 cfs Approach Velocity: 1.9461 ft/s • Splash-over Velocity: 5.9184 ft/s Efficiency: 0.7739 Hydraulic Analysis Report Project Data Project Title: SALE-0036 First Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 3 Notes: Subcatchment 20S Gutter Input Parameters Longitudinal Slope of Road: 0.0400 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 7.8300 ft Gutter Result Parameters Design Flow: 2.6600 cfs Gutter Depression: 0.0000 in Area of Flow: 0.6131 ft^2 Eo (Gutter Flow to Total Flow): 0.5450 Gutter Depth at Curb: 1.8792 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 2.2834 cfs Bypass Flow: 0.3766 cfs Approach Velocity: 4.3386 ft/s • Splash-over Velocity: 5.9184 ft/s Efficiency: 0.8584 Project Data Hydraulic Analysis Report • Project Title: SALE-0036 First Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 4 Notes: Subcatchment 20S (Single Catch Basin for Bypass of Double grate CB) Gutter Input Parameters Longitudinal Slope of Road: 0.0400 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 3.7744 ft Gutter Result Parameters • Design Flow: 0.3800 cfs Gutter Depression: 0.0000 in Area of Flow: 0.1425 ft^2 Eo (Gutter Flow to Total Flow): 0.8667 Gutter Depth at Curb: 0.9059 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane , Grate Width: 2.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 0.3345 cfs Bypass Flow: 0.0455 cfs Approach Velocity: 2.6673 ft/s iSplash-over Velocity: 5.91.84 ft/s Efficiency: 0.8802 Hydraulic Analysis Report • Project Data Project Title: SALE-0036 First Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 5 Notes: Subcatchment 15S CB Left Gutter Input Parameters Longitudinal Slope of Road: 0.0500 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 7.2923 ft Gutter Result Parameters • Design Flow: 2.4600 cfs Gutter Depression: 0.0000 in Area of Flow: 0.5318 ft^2 Eo (Gutter Flow to Total Flow): 0.5751 Gutter Depth at Curb: 1.7501 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 2.1775 cfs Bypass Flow:, 0.2825 cfs Approach Velocity: 4.6260 ft/s • Splash-over Velocity: 5.9184 ft/s Efficiency: 0.8851 Hydraulic Analysis Report • Project Data Project Title: SALE-0036 Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 6 Notes: Subcatchment 15S CB Right Gutter Input Parameters Longitudinal Slope of Road: 0.0500 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 . Gutter Width: 2.0000 ft Width of Spread: 5.9810 ft Gutter Result Parameters • Design Flow: 1.4500 cfs Gutter Depression: 0.0000 in Area of Flow: 0.3577 ft^2 Eo (Gutter Flow to Total Flow): 0.6627 Gutter Depth at Curb: 1.4354 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 1.3779 cis Bypass Flow: 0.0721 cfs Approach Velocity: 4.0534 ft/s • Splash-over Velocity: 5.9184 ft/s Efficiency: 0.9503 Hydraulic Analysis Report Project Data Project Title: SALE-0036 First Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 7 Notes: Subcatchment 18S CB Left Gutter Input Parameters Longitudinal Slope of Road: 0.0500 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 5.4471 ft Gutter Result Parameters • Design Flow: 1.1300 cfs Gutter Depression: 0.0000 in Area of Flow: 0.2967 ft^2 Eo (Gutter Flow to Total Flow): 0.7053 Gutter Depth at Curb: 1.3073 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 1.0990 cfs Bypass Flow: 0.0310 cfs Approach Velocity: 3.8084 ft/s . Splash-over Velocity: 5.9184 ft/s Efficiency: 0.9726 Hydraulic Analysis Report • Project Data Project Title: SALE-0036 First Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 8 Notes: Subcatchment 18S CB Right Gutter Input Parameters Longitudinal Slope of Road: 0.0500 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread:4.2961 ft Gutter Result Parameters • Design Flow: 0.6000 cfs Gutter Depression: 0.0000 in Area of Flow: 0.1846 ft^2 Eo (Gutter Flow to Total Flow): 0.8123 Gutter Depth at Curb: 1.0311 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 0.5996 cfs Bypass Flow: 0.0004 cfs Approach Velocity: 3.2510 ft/s Splash-over Velocity: 5.9184 ft/s Efficiency: 0.9993 I Hydraulic Analysis Report Project Data Project Title: SALE-0036 First.Street/Traders Way Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis q Notes: Subcatchment 22S Gutter Input Parameters Longitudinal Slope of Road: 0.0480 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 5.2822 ft Gutter Result Parameters Design Flow: 1.0200 cfs Gutter Depression: 0.0000 in Area of Flow: 0.2790 ft^2 Eo (Gutter Flow to Total Flow):.0.7193 Gutter Depth at Curb: 1.2677 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width: 4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 0.9981 cfs Bypass Flow: 0.0219 cfs Approach Velocity: 3.6557 ft/s Splash-over Velocity: 5.9184 ft/s Efficiency: 0.9785 r Hydraulic Analysis Report Project Data Project Title: SALE-0036 Designer: PMB Project Date: Monday, July 16, 2018 Project Units: U.S. Customary Units Curb and Gutter Analysis: Curb and Gutter Analysis 10 Notes: Subcatchment 16S Gutter Input Parameters Longitudinal Slope of Road: 0.0480 ft/ft Cross-Slope of Pavement: 0.0200 ft/ft Uniform Gutter Geometry Manning's n: 0.0150 Gutter Width: 2.0000 ft Width of Spread: 4.4351 ft Gutter Result Parameters Design Flow: 0.6400 cfs Gutter Depression: 0.0000 in Area of Flow: 0.1967 ft^2 Eo (Gutter Flow to Total Flow): 0.7983 Gutter Depth at Curb: 1.0644 in Inlet Input Parameters Inlet Location: Inlet on Grade Inlet Type: Grate Grate Type: Curved vane Grate Width:4.0000 ft Grate Length: 2.0000 ft Local Depression: 0.0000 in Inlet Result Parameters Intercepted Flow: 0.6388 cfs Bypass Flow: 0.0012 cfs Approach Velocity: 3.2536 ft/s . Splash-over Velocity: 5.9184 ft/s Efficiency: 0.9981 NEW ENGLAND CIVIL ENGINEERING CORP. 265 ESSEX STREET,SUITE 102,P.O.BOX 3026,SALEM,MA 01970 • PH:978.741.7401-WWW.ENGINEERINGCORPORATION.COM d . July 5, 2018 Ms. Amanda Chiancola Staff Planner Office of Planning and Community Development 120 Washington Street Salem, MA 01970 Re: City of Salem RFQ R-50—Od-Call Civil Engineering Support Services, Task Order No. 36 - Peer Review Services, 40 First Street and 45 Traders Way, Salem, MA Dear Amanda: We are pleased to support the Salem Planning Board with peer review services for the above referenced project. We understand the project will be presented at your next July 5, 2018 meeting, we have prepared this addenda to our June 12, 2018 preliminary peer review letter for your use at that meeting. We have not completed our review of the Applicant's June 27, 2018 response letter and supporting plans and documents, and anticipate having to revisit a number of areas for review following receipt of additional information from the Applicant. Project Understanding_ • The developer(Peter Lutz/Paval Espinal)proposes a redevelopment project(Traders Village) at the current site of 40 First Street and 45 Traders Way. The project will involve construction of new buildings,parking garages, and related site work and utilities. • The City of Salem requests an independent peer review of the proposed development plans and documentation including stormwater management, drainage, and on-site engineering utility issues covered by the Environmental Impact Statement. • Included in the peer review will be consideration of existing and proposed utilities, sewer separation and infiltration issues, water main capacity and water valve status, and adequacy of existing utilities to serve the project. • Peer review will not require compliance with requirements of the Flood Hazard Overlay District special permit. • Specific documents to be reviewed include a Planned Unit Development Special Permit Application(3 pages), a Site Plan Review Application(3 pages),permit cover letter, Project Narrative(2 pages), Environmental Impact Statement(15 pages), Stormwater Report dated 2/28/18, Lighting Plan(4 sheets), and a set of Design Drawings dated 3/27/18 (10 sheets), Landscape Plan (5 pages), June 27, 2018 peer review response letter and supporting documents, WATER RESOURCES - BURIED INFRASTRUCTURE-PUBLIC WORKS - CONSTRUCTION ADMINISTRATION - LAND DEVELOPMENT • The City of Salem has retained a traffic engineer to review the traffic access, egress, and site • circulation issues as well as parking; so those elements are not included as part of this peer review. Review Comments: • NECE prepared a peer review letter dated June 12, 2018. • The following peer review comments to be appended to the June 12,2018 letter: • City Engineering Department Feedback The Salem City Engineer requests confirmation that the existing collector sewers on Traders Way and First Street have adequate capacity and condition to accept the peak flows generated from the development. In addition to the previous requests for information about existing pipe sizes and slopes, and the service area and flows conveyed by sewer in the easement, the City requests the applicant confirm that there is adequate capacity in the existing sewer during peak flows to receive the peak hour flows to be generated by Cne proposed development. The City also requests the condition of the pipe to receive additional flows be confirmed through closed circuit televised pipeline inspection from the points of proposed connection to the downstream interceptor sewer at Mooney and Highland Avenue. • Wetland Impacts The City requests additional information to consider potential impacts to the wetland resource area. The applicant has provided pre and post-development flow rate projections for flows leaving the 0 project site. The City requests the Applicant provide additional data relative to the pre and post- development flows entering the wetland resource area within the project site, including both peak flows and total volume for the design storms. In addition, the City requests additional information about the dog park proposed on the project site adjacent to the wetland resource area, including spot grades and drainage patterns and operations and maintenance plan to prevent dog waste or runoff from entering the resource area. If you have any questions or require additional information,please do not hesitate to contact me at any time on my cell phone at 978-767-5415 or at my Salem office at 978-741-7401. Sincerely, William M. Ross, P.E. Project Manager/Principal Engineer New England Civil Engineering Corp. Cc: David Knowlton, City Engineer Clients/Salem/TradersWay06l22018 review letterAmend NEW ENGLAND CIVIL ENGINEERING CORP. Page 2 of 2 Project file:SALE-0036 WILLIAMS SPARAGES [NUM. f1ANNM •SMVEYM June 27,2018 Ms.Amanda Chiancola,Staff Planner Office of Planning and Community Development 120 Washington Street Salem,MA 01970 RE: 40 First Street/45 Traders Way,Salem,MA;Peter Lutts&Paval Espinal,Applicants Response to Peer Review Continents by New England Civil Engineering Corp. Dear Amanda, The purpose of this letter is to respond to comments received from New England Civil Engneering Corp.(NECE)as a result of their peer review of Site Plan set and attachments in a letter dated June 12,2018 by Mr.William M.Ross.,P.E. The NECE comments are shown below in italics,and,the Williams&Sparages responses are in the bold text that follows. •Existing Conditions Plans—Sewer Drain Easement The plans appear to indicate.a private utility easement crossing the project along the eastern property line. The project proposes to utilize the sewer pipe but not the drain pipe as part_of this project. Not clear on ownership, contributing catchment areas, or use restrictions on this easement or utilities that would impact the project. Request additional information about the utility easement and private utilities in the easement to understand the contributing catchment areas and any potential impacts on the project. The easement reference is found in Deed Book 36250 Page 432 recorded at the Southern Essex District Registry of Deeds(ESRD)and is shown on Plan Book 287 Plan 45.The easement rights Were to benefit Parcel A and was to be used in common with the Grantee and those lawfully entitled thereto. The drainage and sewer contributing to the existing lines are generated from the property owned now or formerly by Second Pickwick Trust located at 227 Highland Avenue to the best of our knowledge. The current project will not connect into the existing drain line but the sewer connections for buildings 6&7 will connect into the existing ten(10")main as shown on the accompanying site plan set. • Watershed Maps Watershed maps are provided to delineate pre and post-development drainage catchment areas(C2.1 and C2.2).Basis for breaks between catchments are not clear on existing conditions drawings, including breaks between catchments IS and 3S and limits of existing contributing area from shopping complex and roofs in IS. Request clarification that existing complex lots and buildings do not contribute to site beyond delineated IS. Existing catchment areas 4S and SS appear to be mislabeled on plans versus the stormwater report, as are catchment 8S and 7S, model should confirm correct catchments are accounted for. Flow paths corresponding to the time of concentration(Tc)are indicated on most catchment areas, but should be added to proposed 4S and building catchments.Request additional information to facilitate review ofstormwater management plan. • 189 North Main Street,Suite 101 • Middleton, MA 01949 • Tel: (978) 539-8088 • www.wsen9 ineers.com r i Response to Peer Review by NECE 40 First Streetl45 Traders Way June 27,2018 The basis for the break between subcatchments IS&3S is due to our observations in the field and the existing spot grades from our topographic survey. We were fortunate enough that on the day of our site visit it was warm enough to cause snowmelt from the piles located in this area and we were able to determine the direction of surface flow into the existing catch basins shown on our existing condition plan. The.break between 1S&3S is the existing ridge that runs from the southeast to the northwest along Traders Way.The area shown to the south of this ridge flows directly towards Traders Way.There is a watershed divide on the shopping plaza site that sends water to the south and Traders Way and to the north and the existing catch basin which then discharges directly into the wetlands. The contributing area of roof shown in 1S is an estimate based on our field observation and aerial photos of the roof surface and the approximate location of drains. This number is estimated but it is a consistent number in both the existing and proposed conditions for comparison. Based on our topography and our field observation we found that no other areas on the adjacent lots contributed surface runoff directly to our site. We found no other pipes or discharge points from that area that would lead us to believe otherwise. The typos have been corrected on the existing condition watershed map for 4S &SS to match the HydroCAD model.We have double-checked subcatchments 7S&8S on the proposed watershed map and they appear to be correct and are accounted for with the HydroCAD model,see revised map. The Tc for 4S was inadvertently left off and has been added to the revised watershed map. We typically do not add Tc's for buildings as they are such short lengths and the time required for runoff to travel from the most hydrologically distant point of the watershed to the point of collection is almost instantaneous.In this case this will either be a drain or a scupper but we have added them here as requested. •Existing Conditions Plans-Drainage The drainage infrastructure on First Street is shown with incomplete connectivity, including a catch basin and manhole that do not connect to closed drainage on First Street and "approximate"location ofa catch basin and 36"drain pipe on the site. Since the project proposes to connect to City drainage in several locations, we recommend the connectivity be complete inn the vicinity of the proposed connections. Request additional information on existing drainage and connectivity on First Street abutting project. The drain manhole shown on First Street that is not connected to the closed drainage system is a manhole with a Drain Manhole cover and is full of sediment,we are not certain of the function of this structure. We opened the catch basin at the southeast corner of the property and it clearly has a twelve(12")inch diameter reinforced concrete pipe(RCP)discharging to the north but the outlet of this pipe was not found in either the drain manhole of the southeast corner of the 2 Response to Peer Review by NECE . 40 FirstStr-eet/45 Traders Way June 27,2018 premises or the drain manhole with the sewer manhole cover. We presume that there is a connection to the drainage system in First Street through a paved-over structure. The City records show an approximate catch basin where we have shown on our plans and . there is a 36"RCP discharging at the existing headwall on the eastern side of First Street. However,we observed no flow coming out of it at the time of our topographic survey. We presume that the structure is buried or was not installed according to plan.The line will be videoed from the south-side to determine if it exists and if so,it's exact location. •Proposed Grading and Drainage Existing contours are shown on the existing conditions plan and watershed map C2.1. Proposed contours are shown on watershed map C2.2. Neither plan shows both pre and post contours. Proposed Utility Plan(Sheet 4 of 11)provides grades for castings but no. contours or spot grades. Request spot grades, including top and bottom of curb elevations, be included on the plans. Request plans with(cuts and fills)areas identified or highlighted to facilitate review of drainage alteration and flood hazard overlay permits. The reason that we separate pre and post contours on the individual watershed maps as well as breakout existing condition,utility and grading plans are for readability. We will provide a separate sheet that combines all of these features. Typically,top of curb and bottom of curb grades are labeled on the construction set once the design has been finalized. We will provide a cut and fill sheet. •Irrigation Plan An irrigation plan it not provided on utility drawings. Request confirmation if irrigation is proposed and provide additional information about irrigation plan piping, connection to City water main, and backflow prevention and metering. The Applicant will provide an Irrigation Plan prior to the start of construction. •Lighting Plan Plans identify proposed exterior lighting, but do not identify the buried electric lines to the lights or the buildings. Request additional information about proposed buried electric utilities to serve buildings and exterior lights. The Applicant/or utility provider will provide an Electric Layout Plan prior to the start of construction. •Existing Conditions Plans—Water and Sewer Existing conditions do not identify the number,size,or location of existing water mains on Traders Way, and do not clarify the size of the sewer main on First Street(12"or 13').Existing sewer in utility easement from the shopping center does not include invert elevations, with the upstream elevation labeled with a "?"and the downstream invert elevation labeled with "verify".It is not clear how much of the adjacent • 3 Response to Peer Review by NEC1 E • 401=irst Street/45 Traders Way June 27,2018 commercial/residential complexes utilize the existing sewer in-the easement, so the capacity is unlcnown. Request Applicant provide additional information about the number, size, and location of existing water and gas utilities abutting project on First Street and Traders Way, and additional information about the service area served by the sewer easement and existing slopes of the sewer in the easement. The sizes of the water mains and sewer mains are shown on the utility plan.The invert is labeled with a"?"as it was difficult to obtain in the field with a rod due to the amount of flow that was observed in the basin. The"verify"was added as a note that the invert was not attainable in the field. We requested all of the City's records regarding sewer in the area and it is unknown exactly how much sewer flow is tributary to this section. However,the 15"sewer main in First Street is labeled with inverts and a capacity analysis of that pipe can be performed if desired. It is important to note that the City does not have accurate records of all the utilities in this area and that further exploratory work may be required prior to construction to obtain them. Demolition Plan A demolition plan has not been provided for review. While the demolition onsite is primarily limited to site work, it will be useful to depict the proposed cuts and fill areas, limits of tree removal onsite and along City right-of-way,and proposed work to-City curbs and sidewalks for curb cuts. Request Applicant provide additional information about proposed demolition on the site and within street layout. We will provide a Demolition Plan that provides the requested information. •Proposed Utilities-Sewer The plan proposes to utilize existing sewer manholes for connections on First Street and Traders Way, and tapped connections on private sewer in the easement. Request additional information on existing sewer size and slopes to confirm capacity(See Existing Conditions Plan—Water and Sewer comment). See prior response. •Proposed Utilities- Water The plan identifies connecting to existing City water mains at two locations on First Street and one location on Traders Way. The plans do not identify the locations of the existing water mains on both streets or include connectivity of water mains with observed water valves. The plan identifies three tapping sleeves with 6-inch valves. The,City prefers full bodied tee connections with triple valves unless there are operable valves in close proximity to the point of connection. Applicant has proposed to extend a b--inch water into the site at three locations, and reduce to a 4-inch domestic service connection for each building The City does not allows fire service and domestic service to share the same water line without separate shutoff valves, the plans do not identify any valves on 4 fi Response to Peer Review by NFCE 40 First Streed45 Traders Way June 27,2018 domestic or fire service feeds or at any junctions throughout the site. The Cityrequests the Applicant consider looping the waterfeed.through the site connecting the First Street and Traders Way connections to improve isolation and limit service interruptions in the future. Request Applicant.revise plans to eliminate tapping sleeve and valve connections, include additional isolation valves in the City Street following review of revised existing conditions plan by City Engineer,add isolation valves on the site including separate fire and domestic shutoff valves for each building, and consider looping the mainn through the site between First Street and Traders Way. We will provide a revised Utility Plan. •Proposed Utilities-Drainage The design includes increased runoff to Traders Way, catchment 3S includes discharge from 13, 000 sf of impervious areas to Traders Way without being intercepted by catch basins within the project limits,raising concerns about sheet flow in the traveled way and capacity of existing drainage at First Street intersection.Request applicant review road shape and existing drainage capacity at proposed curb cuts on Traders Way and revise drainage design to include catch basins onsite or modem street drainage if necessary to prevent drainage problems on Traders Way. See revised plan and calculations which demonstrate that this is no longer the case due to the realignment of the driveway and drainage systems and there will be a reduction in the rate of runoff to Traders Way. • •Proposed Utilities-Drainage The design includes a limited number of catch basins to serve large and fragmented parking lot.It is difficult to observe how the drainage from the larger parking lots(with parking islands)will drain to single locations without spot grades, contours, and flow arrows if necessary.In addition, runoff received by catch basins may exceed their capacity due to the large catchment areas served(catchment 19S, 20S,and 23Sfor example each discharge 15,000 to 20,000 s f. of impervious area to single locations). Without redundant catch basins, the drainage system may become overwhelmed as stretched capacity is reduced due to trash and vegetation, and may result in surface flooding or ponding.Request Applicant provide additional information to demonstrate how runoff will travel in the parking lots and review the number and location ofproposed drainage catch basins to make sure review proposed drainage catch basin locations and confirm adequate number of structures is provided with consideration for redundancy for reduced inlet capacity due to trash and vegetation. A capacity analysis will be provided demonstrating that the system is adequately designed to handle the proposed stormwater runoff. •Proposed Utilities-Gas Project narrative identifies natural gas as a fuel source for the buildings but gas piping is not identified on the plans.Request additional information about location and size of proposed gas piping. The Applicant/or utility provider will provide a Gas Layout Plan prior to construction. 5 Response to Peer Review by NECE 40 First Street/45 Traders Way June 27,2018 • Garage Drainage and Roof Drainage Plan includes several small at-grade parking garages. The garages do not include drainage or oiUwater separators prior to connection to sanitary sewer.Request Applicant clarify ifgarages require floor drains and connections to sanitary sewer per plumbing code. The six(6)small parking garages will discharge their roof runoff directly into the subsurface system and do not require pretreatment under the DEP Standards for certain roof-types.door drains are required in proposed Building 3/4 but are not required in the small parking garages. •Drainage Alteration Permit(Engineering Dept.) Project includes a number of cut and fill areas, including proposed.fills in excess of three vertical feet.As a result, the project requires a drainage alteration permitfrom Salem Engineering Department. The Applicant will request a Drainage Alteration Permit from the Salem Engineering Department. •Stormwater Management Permit(Planning Dept.) Applicant's Stormwater Report dated February 28,2018 meets requirements.of Stormwater Management Permit. No further response required(see Revised Stormwater Report dated June 27,2018 that reflects revisions to plans). •Stormwater Management Report,Drainage Analysis New Drainage Ou alls—Design includes three new stormwater ou falls. Two of the ou falls discharge to a wetland resource area and one discharges above grade on First Street. These outfalls do not appear to provide 80%removal of total suspended solids (TSS)in accordance with the Mass Stormwater Policy for new development projects, as described in the stormwater Report the outfalls propose 44%TSS removal. The outfall that discharges to grade on First Street provides the required treatment and TSS removal, but it is positioned in a location that discharge must flow over sidewalk and roadway to reach the modeled discharge locate 4L to 6L. Request Applicant confirm the two ou falls provide treatment and TSS removal in accordance with Mass Stormwater Policy and identify how discharge from outfall adjacent to First Street will.reach the drainage system in the street without traveling over the sidewalk and roadway. See revised plans for new outfall locations.We will provide calculations demonstrating compliance with the DEP standards. •Pre and Post Runo11"—Design incorporates nine sub-surface infiltration systems to detain runoff and increase groundwater recharge.Design incorporates connections to City drainage on First Street.Detailed review of Stormwater Report not yet complete. • 6 A Response to Peer Review by NECL' 40 First Street/45 Traders Way June 27,2018 ---- ------------------ No further response required(see Revised Stormwater Report dated June 27,2018 that reflects revisions to plans). • Water Quality—Design incorporates deep sump catch basins and oil/sediment separators for pretreatment prior to discharge to nine sub-surface infiltration systems. The Mass Stormwater Policy allows for infiltration if pre-treatment provides 44%removal of total suspended solids (TSS). The treatment chain proposed does provide 44%TSS removal,however the proposed catch basins are identified as "shallow CB's", and oiUsediment separators in the Mass Stormwater Handbook(Volume 2, Chapter 2,Page 7),specifically the discharge orifices in the first chamber and the inverted elbow discharge in the second chamber. Request Applicant confirm the proposed catch basins will provide 4-foot deep sediment sumps, and proposed separators meet the Mass Stormwater Policy requirements for offline configuration and design considerations. The shallow CB's have a 4'sump,a detail will be provided on the revised plans. It is our understanding that there are other separator units that may be used for spill control(see Volume 2,Chapter 2,Page 7)and that the detail referenced is from the MassHighway 2004 design manual used as an example. The model shown on our site plans details is a Shea Concrete design and is a suitable equivalent that is accepted by DEP. Design incorporates eleven 1,500 gallon oilsediment separators of the same size serving catchments of various sizes. Plans provide two details for the same sized separator.Request Applicant confirm all oillwater separators are proposed to be the same size. . The duplicate detail of the 1,500 gallon oil/sediment has been removed from the plan. We will provide calculations demonstrating compliance with the DEP standards for the sizing of the oil/water separator units with the final drainage design. Design includes a limited number of catch basins to collect the runoff from the parking lots. The catchment areas served by some of the catch basins is too large to provide adequate treatment and TSS removal per the Mass Stormwater Standards which recommend impervious areas be limited to'/z acre for each basin and flows be restricted to less than 3 cubic feet per second. Several basins serve much larger impervious areas,for example the single double grate catch basin is intended to serve a catchment area of over 26,000 sf. (over 20,000 sf impervious)and is predicted to convey flows of 3.67 cfs during a 100 year storm.Request Applicant confirm adequate catch basins are provided to meet the requirements for TSS removal and treatment per Mass Stormwater Standards. We will provide calculations demonstrating the catch basin grate capacities are capable of handling the stormwater runoff with the final drainage design. In cltration—Applicant has provided soil boring/pit information in four locations but has not provided sub-surface soil information for most of the nine proposed infiltration systems. Soil information provided identifies ledge 2-3'deep in three of the four locations and depth to groundwater is not identified. It appears likely that blasting will be required in most of the locations ofproposed infiltration, eight of the nine units identijy the bottom of the system as stone, while one unit proposes the bottom of the system as "broken ledge".Request additional information about the soil,ledge, and groundwater where the subsurface infiltrators are proposed and clarification on how-the infiltration systems will operate..(stone vs. broken ledge).. 7 I .r MIT, Mow kJ s � 00 u9j. d YY'i'y rll rrov�fle'uS�(1 ua .�Qrt M` + ' '� a x'Fh �L�n l Q Q�u �1 th sub R W 1rut fatbiidbo � er rrw�btt pbareiy ' g f isac ©ry ? d F le addia anal wits,ailao ^° ^ 11 'S,ov. AnR 1 i• y » ziP• x s CI�at�' ee AQ Wy 07 R >..-.. .... X- g � , fl1 £ nr » r a Ater tCe1 EspYnaJVA 'a a . 0.7 WAS! .: g h I ? b .. y . ofRz "IM OWN All kilo � ��•, fix` _� ''�' #'s x '.'•�'%° Y C � s �M� �'*. � a° a , „t it ZT; s „�" 4 b R 'fir t � sills 1 E l ylost!V 1. M E lox $3 f . ms Y- 3 1 t ' r W & x Nam ill ° xi PAS 1 Fz An A I s � 5 3 a,, Y .^ ' a `' a.' # «,r s Ap +. Y ,,r I t £ �„5 iy,k � _� � � .z� .�. £ , .�• 5 '4 {� ...t fss° -s�y�,. k � f �. � &; ,P` ;J � 9 .: I '�' t�,. 3,'3'�6t � 'x a•�, �` ?' rr� a r� ws rx � .. � 11 �a,g'�s � k i'�q�, N� � � ° 3, z - r f � Project file: SALE-0036 WILLIAMS SPARAGES ENGNEERS Y PLANNERS .SURVEYORS .. June 27,2018 Ms.Amanda Chiancola,Staff Planner Office of Planning and Community Development 120 Washington Street Salem,MA 01970 RE: 40 First Street/45 Traders Way, Salem,MA;Peter.Lutts&Paval.Espinal,Applicants E Response to Peer Review Comments by New'-England Civil Engineering-Corp. Dear Amanda, The purpose of this letter is to respond to comments received from New England Civil Engineering Corp.(NECE)as a result of their peer review of Site Plan set and attachments in a letter dated June 12,2018 by Mr.William M.Ross.,P.E. The NECE comments are shown below in italics,and,the Williams&Sparages responses are in the bold text that follows. •Existing Conditions Plans-Sewer Drain Easement The plans appear to indicate a private utility easement crossing the project along the eastern property line. The project proposes to utilize the sewer pipe but not the drain pipe as part of this project. Not clear on ownership, contributing icatchment areas, or use restrictions on this easement or utilities,that would impact the project. Request additional information about the utility easement and private utilities in the easement to understand the contributing catchment areas and any potential impacts on the project. The easement reference is found in Deed Book 36250 Page 432 recorded at the Southern Essex District Registry of Deeds(ESRD)and is shown on Plan Book 287 Plan 45.The' easement rights were to benefit Parcel A and was to be used in common with the Grantee and those lawfully entitled thereto. The drainage and sewer contributing to the existing lines aregenerated from the property owned now or formerly by Second Pickwick Trust located at 227 Highland Avenue to the best of our knowledge. The current project will not connect into the existing drain line but the sewer connections for buildings 6&7 will connect into the existing ten(10")main as shown on the accompanying site plan set. • Watershed Maps Watershed maps are provided to delineate pre and post-development drainage catchment areas(C2.1 and C2.2).Basis for breaks between catchments are not clear on existing conditions drawings, including breaks between catchments IS and 3S and limits of existing contributing area from shopping complex and roofs in IS. Request clarification that existing complex lots and buildings do not contribute to site beyond delineated IS. Existing catchment areas 4S and SS appear to be mislabeled on plans versus the stormwater report, as are catchment 8S and 7S, model should confirm correct catchments are accounted for Tlow paths corresponding to the time of concentration(Tc)are indicated on most catchment areas, but should be added to proposed 4S and building catchments.Request additional information to facilitate reviewof stormwaler management plan. 189 North Main Street,Suite 101 • Middleton, MA 01949 • Tel: (978)539-8088 • www.wsengingers.com Response to Peer Review by NECE 40 First Street/4'5 Traders Way June 27,2018 The basis for the break between subcatchments 1S&3S is due to our observations in the field and the existing spot grades from our topographic survey. We were fortunate enough that on the day of our site visit it was warm enough to cause snowmelt from the piles located in this area and we were able to determine the direction of surface flow into the existing catch basins shown on our existing condition plan. The break between 1S&3S is the existing ridge that runs from the southeast to the northwest along Traders Way.The area shown to the south of this ridge flows directly towards Traders Way.There is a watershed divide on the shopping plaza site that sends water to the south and Traders Way and to the north and the existing catch basin which then discharges directly into the wetlands. The contributing area of roof shown in 1S is an estimate based on our field observation and aerial photos of the roof surface and the approximate location of drains. This number is estimated but it is a consistent number in both the existing and proposed conditions for comparison. Based on our topography and our field observation we found that no other areas on the adjacent lots contributed surface runoff directly to our site. We found no other pipes or discharge points from that area that would lead us to believe otherwise. The typos have been corrected on the existing condition watershed map for 4S &5S to match the HydroCAD model.We have double-checked subcatchments.7S&8S on the proposed watershed map and they appear to be correct and are accounted for with the HydroCAD model,see revised map. The Tc for 4S was inadvertently left off and has been added to the revised watershed map. We typically do not add Tc's for buildings as they are such short lengths and the time required for runoff to travel from the most hydrologically distant point of the watershed to the point of collection is almost instantaneous.Li this case this will either be a drain or a scupper but we have added them here as requested. •Existing Conditions Plans-Drainage The drainage infrastructure on First Street is shown with incomplete connectivity, including a catch basin and manhole that.do not connect to closed drainage on First Street and "approximate"location ofa catch basin and 36"drain pipe on the site. Since the project proposes to connect to City drainage in several locations, we recommend the connectivity be complete in the vicinity of the proposed connections. Request additional information on existing drainage and connectivity on First Street abutting project. The drain manhole shown on l+irst.Street that is not connected to the closed drainage system is a manhole with a Drain Manhole cover and is full of sediment,we are not certain of the function of this structure. We opened the catch basin at the southeast corner of the property and it clearly has a ✓H twelve 12" inch diameter reinforced concrete pipe RCP discharging to the north but the � ) p�p (RCP) �� g outlet of this pipe was not found in either the drain manhole at the southeast corner of the 2 Response to Peer Review by N£CG 40 First Street/45 Traders Way June 27,2018 premises or the drain manhole with the sewer manhole cover. We presume that there is a connection to the drainage system in First Street through a paved-over structure. The City records show,an approximate catch basin where we have shown on our plans and . there is a 36"RCP discharging at the existing headwall on the eastern side of First Street. However,we observed no flow coming out of it at the time of our topographic survey. We presume that the structure is buried or was not installed according to plan.The line will be videoed from the south-side to determine if it exists and if so,it's exact location. •Proposed Grading and Drainage Existing contours are shown on the existing conditions plan and watershed map C2.1. Proposed contours are shown on watershed map C2.2. Neither plan shows both pre and post contours. Proposed Utility Plan(Sheet 4 of 11)provides grades for castings but no contours or spot grades. Request spot grades, including top and bottom of curb elevations, be included on the plans.Request plans with (cuts and fills)areas identified or highlighted to facilitate review of drainage alteration and flood hazard overlay permits. The reason that we separate pre and post contours on the individual watershed maps as well as breakout existing condition,utility and grading plans are for readability. We will provide a separate sheet that combines all of these features. Typically,top of curb and bottom of curb.grades are labeled on the construction set once the design has been finalized. We will provide a cut and fill sheet. •Irrigation Plan An irrigation plan is not provided on utility drawings. Request confirmation f f irrigation is proposed and provide additional information about irrigation plan piping, connection to City water main, and backflow prevention and metering. The.Applicant will provide an Irrigation Plan prior to the start of construction. •Lighting Plan Plans identify proposed exterior lighting,but do not identify the buried electric lines to the lights or the buildings. Request additional information about proposed buried electric utilities to serve buildings and exterior lights. The Applicant/or utility provider will provide an Electric Layout Plan prior to the start of construction. •Existing Conditions Plans— Water and Sewer Existing conditions do not identify the number,size,or location of existing water mains on Traders Way, and do not clarify the size of the sewer main on First Street(12"or I S'). Existing sewer in utility easement from the shopping center does not include invert elevations, with the upstream elevation labeled with a "?"and the downstream invert elevation labeled with "verify".It is not clear how much of the adjacent . 3 , Response to Peer Review by NECE 401=irst"Street/45 Traders Way June 27,2018 commercial/residential.complexes utilize the existing sewer in the easement, so the capacity is unknown. Request Applicant provide additional.information about the number, size, and location of existing water and gas utilities abutting project on First Street and 7 raders Way, and additional information about the service area served by the sewer easement and existing slopes of the sewer in the easement. The sizes of the water mains and sewer mains are shown on the utility plan.The invert is labeled with a "T'as it was difficult to obtain in the field with a rod due to the amount of flow that was observed in the basin. The"verify"was added as a note that the invert was not attainable in the field. We requested all of the City's records regarding sewer in the area and it is unknown'exactly how much sewer°flow is tributary to this section. However,the 15"sewer main in rirst Street is labeled with inverts and a capacity analysis of that pipe can be performed if desired. It is important to note that the-City does not have accurate records of all the utilities in this area and that further exploratory work may be required prior-to construction to obtain them. Demolition Plan A demolition plan has not been provided for review. While the demolition onsite is primarily limited to site work, it will be useful to depict the proposed cuts and fill areas, limits of tree removal onsite and along City right-of-way, and proposed work to City curbs and sidewaW for curb cuts. Request Applicant provide additional information about proposed demolition on the site and within street layout. We will provide a Demolition Plan that provides the requested information. ° •Proposed Utilities-Sewer The plan proposes to utilize existing sewer manholes for connections on First Street and Traders Way, and tapped connections on private sewer in the easement. Request additional information on existing sewer size and slopes to confirm capacity(See Existing-Conditions Plan— Water and Sewer comment). See prior response. •Proposed Utilities- Water The plan identifies connecting to existing City water mains at two locations on First Street and one location on Traders Way. The plans do not identify the locations of the existing water mains on both streets or include connectivity of water mains with observed water valves. The plan identifies three tapping sleeves with 6-inch valves. The'City prefers full bodied tee connections with triple valves unless there are operable valves in close proximity to the point of connection. Applicant has proposed to extend a 6-inch water into the site at three locations, and reduce to a 4-inch domestic service connection Z for each building. The City does not allow fire service and domestic service to share the same water line without separate shutoff valves, the plans do not identify any valves on 4 t Response to Peer Review by N) CE 40 First Streed45 Traders Way June 27,2018 domestic or fire service feeds or at any junctions throughout,the site. The City requests the Applicant consider looping the waterfeed through the site connecting.the First Street and Traders Way connections to improve isolation and limit service interruptions in the future. Request Applicant revise plans to eliminate tapping.sleeve and valve connections, include additional isolation valves in the City Street following review of revised existing conditions plan by City Engineer, add isolation valves on the site including separate fire and domestic shutoff valves for each building, and consider looping the main through the site between First Street and Traders Way. We will provide a revised Utility Plan. •Proposed Utilities-Drainage The design includes increased runoff to Traders Way, catchment 3S includes discharge from 13, 000 sf of impervious areas to Traders Way without being intercepted by catch basins within the project limits, raising concerns about sheetflow in the traveled way and capacity of existing drainage at First Street intersection. Request applicant review road shape and existing drainage capacity at proposed curb cuts on Traders Way and revise drainage design to include catch basins onsite or modify street drainage if necessary to prevent drainage problems on Traders Way. See revised plan and calculations which demonstrate that this is no longer the case due to the realignment of the driveway and drainage systems and there will be a reduction in the rate of runoff to'Traders Way. •Proposed Utilities-Drainage The design includes a limited number gI'catch basins to serve large and fragmented parking lot. It is difficult to observe how the drainage from the larger parking lots(with parking islands)will drain to single locations without spot grades, contours, and flow arrows if necessary.In addition, runoff received by catch basins may exceed their capacity due to the large catchment areas served(catchment 19S,20S, and 23Sfor example each discharge 15,000 to 20,000 sf of impervious area to single locations). Without redundant catch basins, the drainage system may become overwhelmed as stretched capacity is reduced due to trash and vegetation, and may result in surface flooding or ponding.Request Applicant provide additional information to demonstrate how runoff will travel in the parking lots and review the number and location ofproposed drainage catch basins to make sure review proposed drainage catch basin locations and confirm adequate number of structures is provided with consideration for redundancy for reduced inlet capacity due to trash and vegetation. A capacity analysis will be provided demonstrating that the system is adequately designed to handle the proposed stormwater runoff. •Proposed Utilities-Gas Project narrative identifies naturalgas as a fuel source for the buildings but gas piping is not identified on the plans.Request additional information about location and size of proposed gas piping. The Applicantlor utility provider will provide a Gas Layout Plan prior to construction. Response to Pcer Review by NEC 40 First Street/45 Traders Way June 27,2018 r Garage Drainage and Roof Drainage Plan includes several small at-grade parking garages. The garages do not include drainage or oil/water separators prior to connection to sanitary sewer. Request Applicant.clarify ifgarages require floor drains and connections to sanitary.sewer per plumbing code. The six(6)small parking garages will discharge their roof runoff directly into the subsurface system and do not require pretreatment under the DEP Standards for certain roof-types.Floor drains are required in proposed Building 3/4 but are not required in the small parking-garages. •Drainage Alteration Permit(Engineering Dept) Project includes a number of cut and fill areas, including proposed fills in excess of three vertical feet.As a result, the project requires a drainage alteration permat from.Salem Engineering Department. The Applicant will request a Drainage Alteration Permit from the Salem Engineering Department. •Stormwater Management Permit(Planning Dept.) Applicants Stormwater Report dated February 28, 2018 meets requirements of Stormwater Management Permit. No further response required(see Revised Stormwater Report dated June 27,2018 that reflects revisions to plans). •Stormwater Management Report,Drainage Analysis New Drainage Outfalls—Design includes three new stormwater outfalls. Two of the ou falls discharge to a wetland resource area and one discharges above grade on First Street. These outfalls do not appear to provide 80%removal of total suspended solids (TSS)in accordance with the Mass Stormwater Policy for new development projects, as described in the stormwater Report the outfalls propose 44%TSS removal. The outfall that discharges to grade.on First Street provides the required treatment and TSS removal, but it is positioned in a location that discharge must flow over sidewalk and roadway to reach the modeled discharge locate 4L to 6L. Request Applicant confirm the two ou falls provide treatment.and TSS removal in accordance with Mass Stormwater Policy and identify how discharge from outfall adjacent to First Street will reach the drainage system in the street without traveling over the sidewalk and roadway. See revised plans for new outfa111ocations.We will provide calculations demonstrating compliance with the DEP standards. Pre and Post Runoff—Design incorporates nine sub-surface infiltration systems to detain runoff and increase groundwater recharge.Design incorporates connections to City drainage on First Street.Detailed review of Stormwaler Report not yet complete. 6 I Response to Peer Review by NLCE_ 40 First St eet/4'5 Traders Way June•27,2018 No further response required(see Revised Stormwater Report dated June 27,201.8 that reflects revisions to plans). • Water Quality—Design incorporates deep sump catch basins and oil/sediment separators for pretreatment prior to discharge to nine sub-surface infiltration systems. The Mass Stormwater Policy allows for infiltration ifpre-treatment provides 44%removal of total suspended solids (TSS). The treatment chain proposed does provide 44%M removal,however the proposed catch basins are identified as "shallow CB's", and oil/sediment separators in the Mass Stormwater Handbook(volume 2, Chapter 2, Page 7),specifically the discharge orfices in the first chamber and the.inverted elbow discharge in the second chamber. Request Applicant confirm the proposed catch basins will provide 4-foot deep sediment.sumps, and proposed separators meet the Mass Stormwater Policy requirements for offline configuration and design considerations. The shallow CB's have a 4' sump,a detail will be provided on the revised plans.It is our understanding that there are other separator units that may be used for spill control(see Volume 2,Chapter 2,Page 7)and that the detail referenced is from the MassHighway 2004 design manual used as an example. The model shown on our site plans details is a Shea Concrete design and is a suitable equivalent that is accepted by DEP. Design incorporates eleven 1,500 gallon oil/sediment separators of the same size serving catchments of various sizes. Plans provide two details for the same sized separator.Request Applicant confirm all oil/water separators are proposed to be the same size. The duplicate detail of the 1,500 gallon oil/sediment has been removed from the plan. We will provide calculations demonstrating compliance with the DEP standards for the sizing of the oil/water separator units with the final drainage design. Design-includes a limited number of catch basins to collect the runofffrom the parking lots. The catchment areas served by some of the catch basins is too large to provide adequate treatment and TSS removal per the Mass Stormwater Standards which recommend impervious areas be limited to %acre for each basin and flows be restricted to less than 3 cubic feet per second. Several basins serve much larger impervious areas,for example the single double-grate catch basin is intended to serve a catchment area of over 26,000 s,f. (over 20,000 sf impervious)and is predicted to convey flows of 3.67 cfs during a 100 year storm.Request Applicant confirm adequate catch basins are provided to meet the requirements for TES removal and treatment per Mass Stormwater Standards. We will provide calculations demonstrating the catch basin grate capacities are capable of handling the stormwater runoff.with the final drainage design. In filtration—Applicant has provided soil boring/pit information in four locations but has not provided sub-surface soil information for most of the nine proposed infiltration systems. Soil information provided identifies ledge 2-3'deep in three of the four locations and depth to groundwateris.not identified It appears likely that blasting will be required in most of the locations ofproposed infiltration, eight of the nine units identify the bottom of the system as stone, while one unit proposes the bottom of the system as "broken ledge". Request additional information about the soil, ledge, and groundwater where the subsurface infiltrators are proposed and clarification on how the infiltration systems will.operate(stone vs. broken ledge). 7 �av � "t ,r� � E" ���r� ..,�,,,d as -�tt r�� ... .` � a�x Sx , y •i " LZ VON d0 Tirst Streff �eUl skim Ll � A �4'C'c; s���l prnv�dec�it►oz�ato►l tetxtt atrc�n� kuaw the final 1ort;tto`As of tt saki �s�i�face sj�stecr►s � n �Px � . ,. , We;tr zst that o w�1T find; e aboV�xespolases tQ the peer re i&w-R) d tits oar�ded by F( E. x� x z Satls �ctor Should you have any addltlbnal quson commehis,oroiaeenls;please do now, o €' » hesitat'�.to.cont��t,r�����tione r5>�etnail tt tt xw p .VY .1 H� Vl11 Sf.fi ° " H ;; tt isAM, a 1chaTd�1:W31�1$111S, • x A HI ' RxMMW L Y"_W its {3 ` �1O�q Kim dnF U' ET1Tlg1C1c T N x ctCL I UttS BL aVC�EOini1 € x S 7-m x , gAj .« dr av go $ #x sue : g � a t a - _ ° ITO ' k �, "+ 8 x, ' x ax t Al 1 r. a e i. „.. nil, yjn%, r e lots? &M r a F 3Mrr} � r TWOnow g 3L• .y 2 � `��•,�»�, ��� } �s .���� �� �t� x � ������,» �a � k, „�x�� °` � � �' „ate ��< °� '� I ✓ 3 Y � Sg 'N� b�;� r '� ks �' R e io z STt T M TER REP�I�T 'xoposed Apartm,en C mplex `T"rad4er' Vxlae # o=First 5- of&#45 TYrid s. a) % 0 _j ua y 2 , 201 ' ev :sect jbm, 2 , 201 ' #� = 036 ' ymax�,fealty Trust, A:ppficaft ' F�w Lofts&Navel,nspxr al' 7�origxess.tC', $4W 414:. fr �'"repared�y; M� ?s&Sparage��LLB ' 1 9 N&&'m'a�n' freet,Site 101 Mid-d MAM9V ' Ph 97843,94088 �aSCA 97 5�9�$20�' www.wsenne�rs,com: ` ' I�Qrtna is frnr,Sft�rtnwaE �r'IZ� orb , �► Xti��f�FXI�TIN� R1���{IVIaxC�1,27,2DI�x�va"sad Ju .e 2 � 0�:.8)` WSDS . �LAlt DVt. Jf, utv WILL ,ass�3 �� �P�?►1Z�G�S Mitigative Drainage Analysis 40 First Street &45 Trader's Avenue ' Salem, Massachusetts February 28,2018 ' Revised: June 27, 2018 1.0 Purpose: 1 The purpose of this analysis is to compare the existing condition to the proposed condition or the post-development condition for the proposed development by analyzing the surface runoff rates to the limit of the watershed analysis shown on the accompanying maps.The results of this analysis are presented in the summary table that follows. 2.O Introduction: The site is an 8.95±acre parcel located northeasterly of the intersection of Traders Way,First Street and Whalers Lane in Salem MA.The property is bounded to the north by an existing shopping center known n/f as Highlander Plaza and to the east by existing apartment buildings known n/f as ' Pequot Highlands.The majority of the property is covered with woods in good condition with large areas of ledge outcroppings and areas where boulders have been placed. There has been some drainage improvements on the lot as a result of the construction of First Street and Traders Way as can be seen by the existing drainage features that were located during our topographic survey. The Applicant plans to improve the site by constructing a Clubhouse with pool,patio and recreation area along with six(6)apartment buildings,two (2) of which will have first floor retail space,eight (8) parking garages which can contain six(6)vehicles,surface parking,walkways and utility installation. The paved driveway will be accessed from both Traders Way and First Street with subsurface Stormwater management areas for peak runoff rate mitigation,landscaping,water, sewer,gas and electric. ' It should be noted that there are no direct wetland alteration associated with this project. However, a Notice of Intent filing will be required with the City of Salem Conservation Commission under the Massachusetts Wetland Protection Act. 3.0 Existing Condition Soils Analysis: (No Change-This section not reprinted) In order to model the excess runoff for both the existing and proposed watershed condition,the parent soils on site were mapped using the Web Soil Survey(WSS)made available on the United States Department of Agriculture(USDA)National Resources Conservation Service(NRCS)website. The WSS provides vital soil data and information such as Hydrologic Soil Group(HSG)which is ' then input into a mathematical model to generate runoff curve numbers. The user inputs the soil cover type as well as the hydrologic soil group to generate a weighted curve number(CN)and also uses the topography of the land to generate a time of concentration(Tc)from which the stormwater .runoff rate as well as volume may be calculated for a certain watershed for comparison. The-soils present on site are comprised of 102E,Chatfield-Hollis-Rock Outcrop Complex,15-35% slopes,with a hydrologic soil group of"D";73A,Whitman Fine Sandy Loam,0-3%slopes, ' Page 1.1 r'. #F �`� �.e r f ► Mitigative Drainage Analysis ' 40 First Street&45 Traders Way,'Salem, MA February 28, 2018 Revised:June 27, 2018 extremely stony,with hydrologic soil group"D";and 602,Urban Land,not rated wil-h a hydrologic soil.group of"D" (assumed based on surrounding soils&previous test pits). 4.0 Stormwater Modeling Methodology: The mathematical model used in this analysis was provided using the HydroCAD,V 10.00-20, developed by HydroCAD Software Solutions LLC. HydroCAD is a program used to model the hydrology and hydraulics of stormwater runoff and is based largely on programs and techniques developed by the NRCS,specifically TR-20 and TR-55 as well as other hydraulic calculation methods. HydroCAD allows the user,for a given rainfall event,to generate runoff hydrographs for single or multiple watersheds and is used to determine if a given drainage system is adequate under the desired conditions and to predict flooding or other hydraulic impacts at specified locations such as erosion. Three(3)design storm events were analyzed and the results presented in the Total Peak Rate of Runoff Comparison Table that follows for the 2,10,and 100 year storm events for comparison. 5.0 Existing Condition Watershed: (No Change-This section not reprinted I The selected edge of comparison is the property boundary lines and the up-gradient areas tributary thereto for comparison with the proposed condition.The area tributary to this selected edge of comparison is shown on the accompanying watershed&soils map. Subcatchment EX-CB includes roof and parking lot runoff from the shopping plaza and flows towards the existing drainage system north of the site and then discharges into the existing. bordering vegetated wetlands on site.EX-TRADERS is the westerly portion of the site that is tributary to the existing municipal drainage system on Traders Way. EX-CULVERT is the central ' and northwest portion of the site that is tributary to the existing bordering vegetated wetlands which then discharges via 30"reinforced concrete pipe culvert to the existing land owned N/f City of Salem Conservation Commission. EX-FIRST is the northeast and southeast portion of the site that 1 is tributary to the First Street drainage system which also is conveyed to the City of Salem land.EX- PARK is the paved parking area owned by the shopping plaza and is tributary to the site in the northerly corner which combines with EX-EAST to flow towards the existing property occupied by the apartment buildings known as Pequot Highlands. Using the methods described in the stormwater modeling methodology above,runoff curve numbers and times of concentration are generated for each watershed for the existing condition to be used for comparison with the proposed condition described below.A schematic of the mathematical model and the results of the calculations for the 2 year,10 year,and 100 year Type III, 24-hour storm events are included in this report. 'It is important to note that there was no change in the Existing Condition watershed analysis from the February 28,2018 report,therefore,we have not included the hydrocad output or existing . conditions watershed map in order to reduce the amount paper and size of the report. Page 1-2 Mitigative Drainage Analysis ' 40 First Street&45 Traders Way,Salem, MA February 28, 2018 Revised:June 27,2018 6.0 Proposed Condition Watershed: Similar to the existing condition,the selected edge of comparison is the property boundary Pules and the up-gradient areas tributary thereto for comparison with the existing condition.All the stormwater runoff from within the limit of watershed analysis flows to this selected edge of comparison. Surface runoff has been divided into multiple subcatchments which are intercepted by deep sump catch basins with hoods for pre-treatment then conveyed to oil/water separator units for further treatment prior to being discharged either to grade or to a subsurface structure where topograplucally feasible. The subsurface structures will consist of either Cultec 10OHD units or Cultec 330XL units or,their approved equivalent with 4'of broken ledge below the bottom of the chambers for additional storage volume. A schematic of the mathematical model and the results of the calculations for the 2 year,10 year,and 100 year,Type III,24-hour storm events are included in this report along with performance summaries of the subsurface structures. 7.0 Compliance with DEP Stormwater Management Standards: • Standard 1: No neu)stormwater conveyances(e.g. outfalls)may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. r New stormwater runoff requiring treatment as well as existing paved areas will be treated prior to being discharged towards any wetlands or waters. • Standard 2: Stormwater management systems shall be designed so that post-development peak discharge rates do not exceed pre-development peak discharge rates. This Standard may be waived for discharges to land subject to coastal storm flowage as defined in 310 CMR 10.04. See the summary table that follows which demonstrates the post-development peak discharge rates are less than the existing peak discharge rates. 1 Standard 3: Loss of annual recharge to groundwater shall be eliminated or minimized through the use of infiltration measures including environmentally sensitive site design,low impact development techniques,stormwater best management practices,and good operation and maintenance. At a minimum, the annual recharge from the post-development site shall approximate the annual recharge from the pre-development conditions based on soil type. This Standard is met zvhen the stormwater management system is designed to infiltrate the required recharge volume as determined in accordance 1 with the Massachusetts Stormwater Handbook. 1 -page 1-3 I Mitigative Drainage Analysis 40 First Street&45 Traders Way,Salem, MA February 28, 2018 Revised:June 27, 2018 Groundwater recharge is provided in the volume below the outlets of both the surface and subsurface Stormwater management areas. • Standard 4: Stormwater management systems shall be designed to remove 80% of the average annual post- construction load of Total Suspended Solids(TSS). This Standard is met when: a. Suitable practices for source control and pollution prevention are identified in a long-term pollution prevention plan,and thereafter are implemented and maintained; b. Structural stormwater best management practices are sized to capture the required water quality volume determined in accordance with the Massachusetts Stormwater Handbook;and c.Pretreatment is provided in accordance with the Massachusetts Stormwater Handbook . . The project will utilize deep-sump catch basins,oil/grit separators,and sub-surface i infiltration structures to provide treatment.See attached calculations that demonstrate that the project meets this standard. . • Standard 5: For land uses with higher potential pollutant loads,source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate or reduce the discharge of stornaoater runoff from such land uses to the maximum extent practicable. If through source control and/or pollution prevention all land uses with higher potential pollutant toads cannot be completely protected from exposure to rain, snow melt,and stormwater runoff, the proponent shall use specific structural stornavater BMPs determined by the Department to be suitable for such-uses as provided in the Massachusetts Stormwater Handbook. Stormwater discharges from land uses with higher potential pollutant loads shall also comply with the requirements of the Massachusetts Clean Waters Act,M.G.L.c.21,§§26-53 and the regulations promulgated there under at 314 CMR 3.00, 314 CMR 4.00 and 314 CMR 5.00. This project is not being considered as a LUHPPL. • Standard 6: Stormwater discharges within the Zone H or Interim Wellhead Protection Area of a public water supply,and stornawater discharges near or to any other critical area, require the use of the specific source control and pollution prevention measures and the specific structural stornavater best management practices determined by the Department to be suitable for managing discharges to such areas,as provided in the Massachusetts Stormwater Handbook. A discharge is near a critical area if j there is a strong likelihood of a significant impact occurring to said area, taking into account site- specific factors. Stormwater discharges to Outstanding Resource Waters and Special Resource Waters shall be removed and set back from the receiving water or wetland and receive the highest and best ' practical method of treatment. A "storm water discharge"as defined in 314 CMR 3.04(2) (a) (1 or(b) to an Outstanding Resource Water or Special Resource Water shall comply with 314 CMR 3.00 and 314 CMR 4.00. Stormwater discharges to a Zone 1 or Zone A are prohibited unless essential to the operation of public water supply. The property and associated development does not lie within an Interim Wellhead Protection Area(IWPA) of a public water.supply,a Zone I or a Zone II. Page°1-4 I • 1 Mitigative Drainage Analysis 40 First Street&45 Traders Way, Salem, MA February 28, 2018 Revised:June 27, 2018 • Standard 7: A redevelopment project is required to meet the following Stornuvater Management Standards only to the maximum extent practicable:Standard 2, Standard 3,and the pretreatment and structural best management practice requirements of Standards 4,5,and 6. Existing stormwater discharges shall comply with Standard 1 only to the maximum extent practicable. A redevelopment project shall also comply with all other requirements of the Stormwater Management Standards and improve existing conditions. This project is not being considered as a redevelopment. • Standard 8: A plan to control construction-related impacts including erosion,sedimentation and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation,and pollution prevention plan)shall be developed and implemented. A Stormwater Pollution Prevention Plan(SWPPP)will be submitted prior to land disturbance. • Standard 9: A long-term operation and maintenance plan shall be developed and implemented to ensure that . stormwater management systems function as designed. A Long Term Operation and Maintenance Plan(O&M)will be provided in the SWPPP. • Standard 10: All illicit discharges to the stormwater management system are prohibited. There are no proposed illicit discharges into the Stormwater Management Systems to be 1 constructed as shown on the site plan. 8.0 Conclusion: tAs can be seen by examining the following summary&performance tables,the proposed stormwater management system revisions are still effective for mitigating the peak flow rates of runoff from the limit of the watershed analysis for the 2,10,and 100 year storm events. Although there is a negligible increase for the 2 and 10 year storm events to the existing 30"culvert;there is an overall decrease in the amount of runoff generated from within the fin-lit of the watershed analysis according to the mathematical model for all three design storms to the downstream point of comparison. It should be noted that many of the sections presented in the first Stormwater Report did not change with the latest'revisions,therefore,in order to conserve on the amount of paper and the size of the report to review,we have left out the duplicitous information.Namely,Existing Conditions HydroCAD printout,Stormwater Checklist,USGS Locus Map,O&M,LTPPP,CPPPP,Soil Logs, NRCS Soil Survey,Snow disposal guidelines&Deicing Chemical Storage. 1 -Page 1-. Mitigative Drainage Analysis 40 First Street&45 Traders Way, Salem, MA February 28, 2018 Revised:June 27, 2018 iTotal Peak Rate of Runoff Comparison Location (Total Flow from within limit of analysis) Link 6L 2-Year 10-Year 100-Year 24 Hour 24 Hour 24 Hour Description Type III Type III Type III Storm Event Storm Event Storm Event Existing Peak Rate of Runoff 12.6 23.1 39.0 (cfs) Proposed Peak tRate of Runoff 11.3 17.9 31.6 (cfs) Increase/ Decrease -1.3 -5.2 -7.4 Peak Rate of Runoff Comparison Location (Flow to City of Salem Conservation Land) Link 4L 2-Year 10-Year 100-Year 24 Hour 24 Hour 24 Hour Description Type III Type III Type III Storm Event Storm Event Storm Event Existing Peak ' Rate of Runoff 11.3 20.9 35.6 (cfs) I Proposed Peak 9.7 15.6 28.7 Rate of Runoff (cfs) Increase/ -1.6 -5.3 -6.9 Decrease Page 1-6 u e' iF4 it �� gi i Mitigative Drainage Analysis ' 40 First Street&45 Traders Way, Salem, MA February 28,2018 Revised:June 27, 2018 Peak Rate of Runoff Comparison Location (Surface Flow to Traders Way) Link 1L 2-Year 10-Year 100-Year 24 Hour 24 Hour 24 Hour Description Type III Type III Type III Storm Event Storm Event Storm Event Existing Peak Rate of Runoff 1.1 2.1 3.7 (Cfs) Proposed Peak 0.6 1.0 1.7 Rate of Runoff (cfs) Increase/ -0.5 -1.1 -2.0 Decrease Peak Rate of Runoff Comparison Location (Surface Flow to Existing 30" RCP Culvert) Link 2L i 2-Year 10-Year 100-Year 24 Hour 24 Hour 24 Hour ' Description Type III Type III Type III Storm Event Storm Event Storm Event Existing Peak Rate of Runoff 6.5 11.3 18.5 (cfs) Proposed Peak 7.5 11.9 18.1 Rate of Runoff (cfs) Increase/ +1.0 +0.6 -0.4 Decrease Page 1-7 Mitigative Drainage Analysis 40 First Street&45 Traders Way, Salem, MA February 28, 2018 Revised:June 27, 2018 Peak Rate of Runoff - Comparison Location (Surface Flow to First Street) Link 3L 2-Year 10-Year 100-Year 24 Hour 24 Hour 24 Hour Description Type III Type III Type III Storm Event Storm Event Storm Event Existing Peak Rate of Runoff 3.8 7.6 13.6 (cf s) Proposed Peak 1.8 3.1 4.9 Rate of Runoff ' (cfs) Increase/ -2.0 -4.5 -8.7 Decrease Peak Rate of Runoff Comparison Location (Surface Flow to the east) Link 5L 2-Year 10-Year 100-Year 24 Hour 24 Hour 24 Hour Description Type III Type III Type III Storm Event Storm Event Storm Event Existing Peak Rate of Runoff 1.6 2.6 4.1 (cfs) 1 Proposed Peak Rate of Runoff 1.6 2.5 3.7 (cfs) Increase/ Decrease 0.0 -0.1 -0.4 Page 1-8 1 . Mitigative Drainage Analysis 40 First Street&45 Traders Way, Salem, MA February 28,2018 Revised:June 27, 2018 Pond 1P - Subsurface Infiltration Basin-rear parking lot of Bldg. 1 (For 1/2 of roof runoff only - Subcat 8S) Performance Table ' Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration Type III Runoff in (discarded) Total Peak Water ' Storm Event (cfs) (cfs) (cfs) Level(ft) 2 0.3 0.0 0.0 113.80 10 0.4 0.0 0.0 115.12 100 0.6 0.0 0.0 116.34 (32)Cultec Recharger 100 HD Units-4 rows of 8 units Top of Stone=117.0 Top of Chambers=116.50 I 4" Inverts In=115.96 From Roof Drains Bottom of Chambers=115.46 Bottom of 48" Broken Ledge bed=111.46 Pond 2P - Subsurface Infiltration Basin located in parking area adjacent to First Street (Subcats 9S &10S) Performance Table Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration (2)8" HDPE Type III Runoff in (discarded) Culverts Total Peak Water Storm Event (cfs) (cfs) (cfs) (cfs) Level(ft) 2 1.0 0.0 0.00 0.00 107.00 ' 10 1.5 b.0 0.26 0.27 107.95 100 4.0 0.0 2.33 2.33 108.56 (56)Cultec Recharger 330XL Units-7 rows of 8 units Top of Stone=110.25 Top of Chambers=109.75 E12" Inv in=108.75 (2)8" Inv s In=107.95 From Pond 3P (2)8" Inverts out=107.75 To proposed Drain Manhole Bottom of Chambers=107.21 Bottom of 48".Broken Ledge bed=103.21 ' Page 1-9 Mitigative Drainage Analysis 40 First Street&45 Traders Way,Salem, MA February 28, 2018 Revised:June 27, 2018 j ! Pond 3P - Subsurface Infiltration Basin located in parking area adjacent to First Street (Subcat 11S & Flow from Pond 2P) Performance Table Peak Rate of Runoff out(cfs) ' 24 Hour Peak Rate of *Exfiltration (2)8" HDPE Type III Runoff in (discarded) Culverts Total Peak Water Storm Event (cfs) (cfs) (cfs) (cfs) Level(ft) ' 2 1.9 0.0 0.02 0.02 108.38 10 2.8 0.0 0.40 0.40 108.58 100 4.1 0.0 2.37 2.38 109.16 (56)Cultec Recharger 330XL Units-7 rows of 8 units . Top of Stone=109.5 Top of Chambers=109.0 12" Inv's in=108.00 1 4" Inv's in=108.75(From Roof) (2)8" Inverts out=108.33(To Pond 2P) Bottom of Chambers=106.46 Bottom of 48" Broken Ledge bed=102.46 Pond 4P - Subsurface Infiltration Basin located in parking area adjacent to ' First Street (Roof runoff from Building 5 &parking- Subcats 12S &13S) Performance Table Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration Type III Runoff in (discarded) (2)8"HDPE Total Peak Water Storm Event (cfs) (cfs) Culverts(cfs) (cfs) Level(ft) 2 2.2 0.01 0.10 0.11 102.12 10 3.3 0.01 1.23 1.24 102.47 100 4.8 0.01 3.30 3.31 103.30 (54)Cultec Recharger 330XL Units-2 rows of 27 units Top of Stone=103.8 Top of Chambers=103.3 ' 12" inv in=102.3 from Oil/Sediment Separator 4" Inv's in=102:76 from roof drains (2)8" Inv's out=102.50 to Proposed DMH ' Bottom of Chambers=100.76 Bottom of 48" Broken Ledge bed=%.76 1 Page 1-10 t Mitigative Drainage Analysis 40 First Street&45 Traders Way,Salem,MA February 28, 2018 Revised:June 27, 2018 Pond SP - Subsurface Infiltration Basin located in parking area north of Bldg. 5 (Roof runoff from garages &parking- Subcats 14S &15S) Performance Table Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration Type III Runoff in (discarded) 12" HDPE Total Peak Water Storm Event (cfs) (cfs) out (cfs) Level(ft) 2 1.8 0.0 0.0 0.0 108.04 10 2.8 0.0 0.16 0.16 108.69 100 4.3 0.0 1.73 1.73 109.21 (60)Cultec Recharger 330XL Units-4 rows of 15 units Top of Stone=110.0 Top of Chambers=109.50 12" Inv in=108.50 from Oil/Sediment Separator 4" Inv s in=108.96 from roof drains 12" Inv out=108.50 out to Proposed DMH Bottom of Chambers=106.96 Bottom of 48" Broken Ledge bed=102.96 Pond 6P - Subsurface Infiltration Basin located in parking area northwest of Bldg. 6 (Roof runoff from garages &parking- Subcats 17S,18S &21S) Performance Table Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration Type III Runoff in (discarded) 4" HDPE Total Peak Water Storm Event (cfs) (cfs) Culvert(cfs) (cfs) Level(ft) 2 1.3 0.0 0.0 0.0 111.97 10 1.9 0.0 0.0 0.0 113.61 100 2.9 0.0 0.22 0.22. 114.11 (50)Cultec Recharger 330XL Units-5 rows of 10 units Top of Stone=114.50 Top of Chambers=114.0 12"Inv in=113.0 from Oil/Sediment Separator 4" Invs in=113.46 from roof drains 4" Inv out=113.67 Bottom of Chambers=111.46 Bottom of 48" Broken Ledge bed=107.46 Page 1-11 Mitigative Drainage Analysis 40 First Street&45 Traders Way,Salem, MA February 28, 2018 Revised:June 27,2018 Pond 7P - Subsurface Infiltration Basin located in parking area southwest of Bldg. 7 (Runoff from parking- Subcats 16S, 22S &23S) Performance Table Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration Type III Runoff in (discarded) Total Peak Water Storm Event (cfs) (cfs) 12" HDPE (cfs) Level(ft) 2 1.8 0.01 0.02 0.03 113.57 10 2.8 0.01 0.36 0.36 113.79 100 4.2 0.01 2.02 2.02 114.29 (72)Cultec Recharger 330XL Units-12 rows of 6 units Top of Stone=116.25 Top of Chambers=115.75 12" Inv in=114.75 from Oil/Sediment Separators 12" Inv out=113.50 to Proposed DMH Bottom of Chambers=113.21 Bottom of 48" Broken Ledge bed=109.21 Pond 8P Bordering Vegetated Wetlands (Runoff from Shaw's drainage system & proposed parking Subcats 1S, 2S,3S, 7S, &20S) Performance Table. 24 Hour Peak Rate of Peak Rate of Peak Water Level Type III Runoff in Runoff out (ft) Storm (cfs) (cfs) Event * 30" RCP Total Exist. Prop. Exfiltration (cfs) (cfs) (discarded) (cfs) Exist. Prop. Exist. Prop. Exist. Prop. 2 6.5 7.6 0.0 6.45 7.51 6.45 7.51 109.35 109.43 10 11.4 12.1 0.0 11.44 11.89 11.27 11.90 109.67 109.71 100 18.9 18.6 0.01 18.90 18.12 18.47 18.13 110.08 110.06 Top of Earth Berm--110.50 1 30"RCP Inv out=108.45 to First Street drainage system(Pipe will act under inlet control) Page 1-12 Mitigative Drainage Analysis 40 first Street&45 Traders Way,Salem, MA February 28, 2018 Revised:June 27, 2018 II ' Pond 9P - Subsurface Infiltration Basin located in parking area north of Bldg. 7 (Runoff from garages, portion of bldg. 7 & parking- Subcat 19S) Performance Table Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration Type III Runoff in (discarded) Total Peak Water Storm Event (cfs) (cfs) 4" HDPE (cfs) Level(ft) 2 1.6 0.01 0.0 0.01 116.77 10 2.4 0.01 0.0 0.01 118.15 100 3.6 0.01 0.15 0.016 119.47 (70)Cultec Recharger 330XL Units-10 rows of 7 units Top of Stone=120.00 Top of Chambers=119.50 12" Inv in=119.00 from Oil/Sediment Separator ' 4" Inv out=119.17 to drain Iine Bottom of Chambers=116.96 Bottom of 48" Broken Ledge bed=112.46 Pond 28P -Subsurface Infiltration Basin-rear parking lot of Bldg. 1, ' (For NW corner of BLDG 3/4 of roof runoff only- Subcat 27S) Performance Table Peak Rate of Runoff out(cfs) 24 Hour Peak Rate of *Exfiltration Type III Runoff in (discarded) Total Peak Water Storm Event (cfs) (cfs) (cfs) Level(ft) 2 0.3 0.0 0.0 111.88 ' 10 0.4 0.0 0.0 112.74 100 0.6 0.0 0.0 113.98 (48)Cultec Recharger 100 HD Units-3 rows of 16 units Top of Stone=114.0 Top of Chambers=113.50 ' 4".Inverts In=112.96 Bottom of Chambers=112.46 .Bottom of 24" Broken Ledge bed=110.46 Page 1-13 Mitigative Drainage Analysis ' 40 First Street&45 Traders Way, Salem, MA February 28, 2018 Revised:June 27,2018 *Calculated infiltration rate and peak water levels are based upon a rate of 0.09 inches per hour for Hydrologic Soil Group"D"as found in Table 2-1 of the Hydrology Handbook of Conservation Commissioners,March 2002 using Rawls,Brakensiek and Saxton,1982. 9.0 HydroCAD,Data: ' See following pages II t ' i Page 1-14 i OA PRNWM Ciaeo tOWD _ c�wae.sae.. oeReoEeaew M"126 of Ct"10" . aeoe GMAMasae / ewsR i � TWrbSbWn OS PRdRet O No. Pb Skw Bu010-wet" MM . Imm 1 �� �•TRAGER9e Intta aroetown .GG//� . Iwe..R,.emm. gefrp.gaan MTRU EREE M-U I M-M e.m Tp Ca a�i6amten0 NOwiumhoEW FM PIM G i2iR 6dAnpeNV' RRrwRW CPpIC&rI Tae lw'IWmYtli1 MloMot� naa.a..na M� E>kBA eR4Mr 1 RoutingDiagram ia ram for Pro ed R1 9 i� _ =HydroCA pared by Williams&Sparages, Printed 7/1/2018 1 10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street Traders Wa i� y J / y Proposed_RI Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 2. Area Listing(all nodes) Area CN Description (sq-ft) (subcatchment numbers) I 127,427 80 >75%Grass cover,Good,HSG D (1S,2S,3S,4S,SS,6S,7S,9S,10S,12S,15S,16S,18S,19S,20S, 21S,22S,23S) 180,837 98 Paved parking,HSG D (1S,2S,3S,4S,5S,6S,7S,9S,10S,12S,15S,16S,18S,19S,20S,21S,22S, 1 23S) 103,065 98 Roofs,HSG D (1S,2S,5S,7S,8S,11S,12S,13S,14S,15S,17S,18S,19S,20S,21S,22S,23S,24S, 25S,27S) I 41,350 77 Woods,Good,HSG D (1S,2S,6S,19S,26S) 452,679 91 TOTAL AREA I 1 � 1 1 1 , 1 1 1 1C . = 1 , 1 1 1 1 - 1 m41t �. bA 64.w �bt 0 OWAMSGASSB mat MOM T-R MOR NOAD MIMUDa rb. R,taa,t O mat Fw7R 1 . mm M-muFxs. m-TPACO 0 �A mdR PI4l11 Nbub6YlROn A �b d 6uC A.Sx—n PR4R\ MMS 0 / mat / FiToY— 14dRCPCWM7P Q�\ miARK 1. bra..N w *-b except FRf" Routing Diagram for Proposed_R1 Ppared by Williams&Sparages, Printed 7/1/2018 FHyd:CZ10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Proposed Condition Watershed Analysis-Revised June 27 2018-First Street Traders Wa Po Y J ,./ Y Proposed_111 Prepared by Williams&Sparages Printed 7/1/2018 HydroCADO 10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 22 Area Listing(all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 127,427 80 >75%Grass cover,Good,HSG D (IS,2S,3S,4S,5S,6S,7S,9S,10S,1.2S,15S,16S,18S,19S,20S, 21S,225,23S) 180,837 98 Paved parking;HSG D (1S,2S,39;4S,5S,6S,7S,9S,10S,12S,1SS,16S,18S,19S,20S,21S,22S, 23S) 103,065 98 Roofs,HSG D (1S,2S,5S,7S,8S,11S,12S,13S,14S,15S,17S,18S,19S,20S,21S,-22S,235,24S, 25S,27S) 41,350 77 Woods,Good,HSG D (1S,2S,6S,19S,26S) 452,679 91 TOTAL AREA 1 1 IProposed Condition-Watershed Analysis-Revised June 27,2018-First Street/Traders Way i roposed_RI Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 ' HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC page 3 Summary for Subcatchment IS: EX-CB_R Runoff = 3.54 cfs Q 12.13 hrs, Volume= 13,127 cf, Depth= 2.55" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" 1 Area(sf) CN Description 23,719 98 Roofs,HSG D 28,112 98 Paved parking,HSG D 8,545 80 >75%Grass cover,Good,HSG D 1,469 77 Woods,Good,HSG D t 61,845 95 Weighted Average 10,014 16.19%Pervious Area 51,831 83.81%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) ' 8.7 60 0.0100 0.11 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.5 85 '0.0190 2.80 Shallow Concentrated Flow, Paved Kv=20.3 fps 9.2 145 Total i Proposed Condition Watershed Analysis-Revised June 27 2018-First Street/Traders p y J Way Proposed_R1 Type II124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 ._ HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pare 4 Summary for Subcatchment 2S: PR-CULVERT_R Runoff = 1.96 cfs® 12.21 hrs, Volume= 8,045 cf, DeP th= 1.39" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(so CN Description 33,000 77 Woods,Good,HSG D 2,936 98 Paved parking,HSG D 28,532 80 >75%Grass cover,Good,HSG D 4,945 98 Roofs,HSG D 69,413 81 Weighted Average 61,532 88.65%Pervious Area 7,881 11.35%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) ' 9.6 100 0.1560 0.17 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.6 125 0.0500 3.60 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 4.3 390 0.0090 1.53 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 14.5 615 Total aProposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Pa eg5 Summary for Subcatchment 3S: PR-TRADERSb Runoff = 0.49 cfs @ 12.09 hrs, Volume= 1,559 cf, Depth= 1.53" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description ' 10,228 80 >75%Grass cover,Good,HSG D 2,023 98 Paved parkin,HSG D 12,251 83 Weighted Average 10,228 83.49%Pervious Area 2,023 16.51%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.2 60 0-13W 0.46 Sheet Flow, Grass:Short n=0.150 P2=3.10" 2.2 60 Total, Increased to minimum Tc=6.0 min 1 i i 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_RI Type III24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Pade 6 Summary for Subcatchment 4S:PR-PARK ' Runoff = 1.19 cfs® 12.09 hrs Volume= 4 037 cf Dep th= 2.65" Runoff by SCS TR-20 method,UH--SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall--3.10" Area(so CN Description ' 16,283 98 Paved parking,HSG D 1,996 80 >75`Yo Grass cover,Good,HSG D 18,279 96 Weighted Average 1,996 10.92%Pervious Area 16,283 89.08%Impervious Area Tc Length Slope Velocity Capacity Description Oman) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0400 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" ' 1.0 255 0.0400 406 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.3 280 Total, Increased to minimum Tc=6.0 min w Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_tl Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 - HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC paw Summary for Subcatchment 5S: PR-FIRST- Runoff = 1.51 cfs® 12.09 hrs, Volume= 4,780 cf, DeP th= 1.67 Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description ' 2,681 98 . Roofs,HSG D 6,917 98 Paved parking,HSG D 24,696 80 >75%Grass cover,Good,HSG D 34,294 85' Weighted Average 24,696 72.01%Pervious Area 9,598 27.99%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftjsec) (cfs) 2A 40 0.1100 0.28 Sheet Flow, ' Grass:Short n=0.150 P2=3.10" 1.9 290 0.0250 2.55 Shallow Concentrated Flow, _ Unpaved Kv=16.1 fps 4.3 330 Total, Increased to minimum Tc=6.0 min II Proposed Condition Watershed Analysis-.Revised June 27,2018-.First Street/Traders Way Proposed_R1 'Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed .7/1/2018 H,ydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pa E 88 Summary for Subcatchment 6S:PR-EAST Runoff 0.40 cfs @ 12.09 hrs, Volume-- 1,273 cf, Depth= 1.60" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description t 1,500 77 Woods,Good,HSG D 5,885 80 >75%Grass cover,Good,HSG D 2,170 98 Paved parking,HSG D 9,555 84 Weighted Average 7,385 77.29%Pervious Area 2,170 22.71%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.5 50 0.0700 0.24 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.3 100 0.1200 5.58 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 3.8 150 Total, Increased to minimum Tc=6.0 min M Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" j ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC paM99 Summary for Subcatchment 7S: PR-1R I ' Runoff = 1.43 cfs® 12.09 hrs, Volume= 4,731 cf, Depth= 2.45" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description ' 14,215 98 Paved parking,HSG D 4,545 80 >75%Grass cover,Good,HSG D 4,440 98 Roofs,HSG D 23,200 94 Weighted Average 4,545 19.59%Pervious Area 18,655 80.41%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.5 25 0.0100 0.78 Sheet Flow,. ' Smooth surfaces n=0.011 P2=3.10" 1.1 130 0.0100 2.03 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.6 155 Total, Increased to minimum Tc=6.0 min - Proposed Condition Watershed Analysis-Revised June 27 2018-First Street/Tra e rs Way Proposed_R1 Type III24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HvdroCAD Software Solutions LLC Page 10 Summary for Subcatchmen#8S: PR-1/2 BLDG 1 Runoff = 0.30 cfs 0 12.09 hrs, Volume= 1,064 cf, Depth= 2.87' Runoff by SC5 TR-20 method,UH=SCS,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(so CN Description ' 4,452 98 Roofs,HSG D 4,452 100.00%Impervious Area Tc Length Slope Velocity "Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, r r _ S f- Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Spar-ages Printed 7/1/2018 HydroCAD®10.00-20 sjn 06611 ®2017 HydroCAD Software Solutions LLC Pam Summary for Subcatchment 9S:PR-2R Runoff = 1.27 cfs® 12.09 hrs, Volume= 4,261 cf, Depth= 2.55" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(so CN Description 16,652 98 Paved parking,HSG D 3,422 80 >75%Grass cover,Good,HSG D 20,074 95 Weighted Average 3,M 17.05%Pervious Area 16,652 82.95%Impervious Area Tc Length Slope Velocity Capacity Description' ' (min) (feet) (ft/ft) (ftlsec) (cfs) 3.3 25 0.0200 0.13 Sheet Flow, Grass:Short n=0.150 P2=3.10" 1 1.0 125 0.0100 2.03 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.3 150 Total, Increased to minimum Tc=6.0 min 1 t I Proposed Condition Watershed Analysis-Revised June 27,2018-First Street Traders Wa Po ys J / y Proposed_R1 Type H124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pagg 12 Summary for Subcatchment 10S:PR-3R Runoff = 0.99 cfs @ 12.09 hrs, Volume= 3,239 cf, DeP th= 2.35" Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Tame Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" A_rea(sf) CN Description 11,617 98 Paved parking,HSG D 4,923 80 >75%Grass cover,Good,HSG D 16,540 93 Weighted Average ' 4,923 29.76%Pervious Area 11,617 70.24%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) {cfs) 2.6 50 0.1400 0.32 Sheet Flow, Grass:Short n=0.150 P2=3.10" 1A 160 0.0090 1.93 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.0 210 Total, Increased to minimum Tc=6.0 min a 1 Proposed Condition Watershed Analysis-.Revised June 27,2018-First Street/Traders Way Proposed R1 Type 11124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 sln 06611 02017 HydroCAD Software Solutions LLC Page 13_ Summary for Subcatchment 11S: PR-BLDG 2 Runoff = 0.60 cfs® 12.09 hrs, Volume= 2,128 cf, 'Depth= 2.87" ' Runoff by SCS TR-20 method,UH=GCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 8,905 98 Roofs,HSG D 8,905 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, I 1 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD@ 10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Paa 14 Summary for Subcatchment 12S: PR4R Runoff 1.48 cfs @ 12.10 hrs Volume= 5 078 cf Dep th= 2.55" . ' Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs . Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 5,363 98 Roofs,HSG D 14,148 98 Paved parking,HSG D 4,411 80 >75%Grass cover,Good,HSG D 23,922 95 Weighted Average 4,411 18.44%Pervious Area 19,511 81.56%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Sheet Flow,1 6.3 40 0.0100 0.11 Grass:Short n=0.150 1`2=3.10" 0.1 20 0.0200 2.87 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.6 175 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 7.0 235 Total Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders'Way Proposed_R1 Type.III24-hr 2yrRainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 sjn 06611 02017 H,ydroCAD Software Solutions LLC Pag15 Summary for Subcatchment 13S:PR-BLDG 5 _ ` Runoff 0.72 cfs® 12.09hrs, Volume= 2,563 cf, Depth= 2.87" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 10,725 98 Roofs,HSG D 10,725 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 1 I Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Wa Po Y Y Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Page_16 Summary for Subcatchment 14S: GARAGES 5A &5B ' Runoff = 0.16 cfs @ 12.09 hrs, Volume= 578 cf, DeP th= 2.87" ' Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 2,420 98 Roofs,HSG D 2,420 100.00%Impervious Area ' Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 1 I ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Pam Summary for Subcatchment 15S:PR-SR Runoff = 1.67 cfs® 12.09 hrs, Volume= 5,395 cf, Depth= 2.26" Runoff by SCS TR-20 method,UH=SC:.S,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(so CN Description 2,676 98 Roofs,HSG D 16,431 98 Paved parking,HSG D 9,593 80 >75%Grass cover,Good,HSG D ' 28,700 92 Weighted Average . 9,593 33.43%Pervious Area 19,107 66.57%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.0 50 0.0500 0.21 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.1 20 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.7 190 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.8 260 Total, Increased to minimum Tic=6.0 min r i ► 1. r , Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 16S: PR-6R Runoff = 0.25 cfs®1 12.09 hrs, Volume= 804 cf, DeP th= 1.99" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" ' Area(so CN Description 2,384 98 Paved parking,HSG D 2,465 80 >75%Grass cover,Good,HSG D 4,849 89 Weighted Average 2,465 50.84%Pervious Area 2,384 49.16%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0500 1.48 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.6 175 0.0500 454 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.9 200 Total, Increased to minimum.Tc=6.0 min ?t4 #j $t { Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Y Proposed_R1 Type III24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 17S: GARAGES 6A&6B Runoff 0.16 cfs @ 12.09 hrs, Volume= 578 cf, Depth= 2.87" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(so CN Description ' 2,420 98 Roofs,HSG D 2AM 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, r Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Wa Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10y Prepared by Williams&Sparages Printed 7/1/2018 HYdroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 18S:PR-7R Runoff = 0.75 cfs @ 12.09 hrs, Volume= 2,456 cf, DeP th= 2.35" Runoff by SCS TR-20 method,UH=SC5,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 8,105 98 Paved parking,HSG D 3,736 80 >75%Grass cover,Good,HSG D 700 98 Roofs,HSG D 12,541 93 Weighted Average 3,736 29.79%Pervious Area 8,805 70.21%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.9 40 0.5000 0.23 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.6 140 0.0360 3.85 Shallow Concentrated Flow, Paved Kv=20.3 fps 3.5 180 Total, Increased to minimum Tc=6.0 min II ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Pam Summary for Subcatchment 19S:PR-8R ' Runoff = 1.59 cfs @ 12.09 hrs, Volume= 5,263 cf, Depth= 2.45" ' Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) Chi Description ' 13,367 98 Paved parking,HSG D 2,287 80 >75%Grass cover,Good,HSG D 2,8W 77 Woods,Good,HSG D ' 7,356 98 Roofs,HSG D 25,810 94 Weighted Average 5,087 19.71%Pervious Area 20,723 80.29%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) ' 2.9 40 0.5000 0.23 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.7 140 0.0280 3.40 Shallow Concentrated Flow, _ Paved Kv=20.3 fps 3.6 180 Total, Increased to minimum Tc=6.0 min i Proposed Condition Watershed Analysis-Rev' June 27 2018-F'po ys Revised j first Street/Traders Way Proposed_R1 Type III24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD810.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 20S: PP,.-9R Runoff = 1.20 cfs @ 12.09 hrs, Volume= 4,016 cf, Depth= 2.55" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 9,402 98 Paved parking,HSG D 3,247 80 >75%Grass cover,Good,HSG D 6,273 98 Roofs,HSG D 18,922 95 Weighted Average 3,247 17.16%Pervious Area 15,675 82.84%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftjft) (ft/sec) (cfs) 0.3 25 0.0330 1.25 Sheet Flow, ' Smooth surfaces n=0.011 P2=3.10" 0.7 180 0.0480 4.45 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.0 205 Total, Increased to minimum Tc=6.0 min Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 _ HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment 21S: PR-IOR III ' Runoff = 0.34 cfs® 12.09 hrs, Volume= 1,077 cf, Depth= 2.16" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description ' 2,830 98 Paved parking,HSG D 2,414 80 >75%Grass cover,Good,HSG D 726 98 Roofs,HSG D 5,970 91 Weighted Average 2,414 40.44%Pervious Area 3,5% 59.56%Impervious Area 1 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0500 1.48 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.6 175 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.9 200 Total, Increased to minimum Tc=6.0 min 1 1 1 1 1 t 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 H.ydroCAD Software Solutions LLC Paper Summary for Subcatchment 22S:PR-11R Runoff = 0.41 cfs Q 12.09 hrs, Volume= 1,325 cf, De th= 2.08" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 3,673 98 Paved parking,HSG D 3,257 80 >75%Grass cover,Good,HSG D 726 98 Roofs,HSG D 7,656 90 Weighted Average 3,257 42.54%Pervious Area 4,399 57.46%Impervious Area ' Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0400 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.5 125 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.8 150 Total, Increased to minimum Tc=6.0 min 1 . Proposed Condition Watershed Analysis-.Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pam Summary for Subcatchment 23S:PR-12 Runoff = 1.14 cfs® 12.09 hrs, Volume-- 3,820 cf, Depth= 2.55" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description 9,572 98 Paved parking,HSG D 3,245 80 >75%Grass cover,Good,HSG D 5,179 98 Roofs,HSG D 17,996 95 Weighted Average 3,245 18.03%Pervious Area 14,751 81.97%Impervious Area ' Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) 0.3 25 0.0400 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.8 205 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.1 230 Total, Increased to minimum Tc=6.0 min II Proposed Condition Watershed Analysis-Revised June.27,2018-First Street Traders Wa Y / y Proposed R1 Type III24-hr 2 yr Rainfall=3.10" II ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HVdroCAD Software Solutions LLC Page 26 Summary for Subcatchment 24S: PR-1/4 BLD 6 Runoff = 0.18 cfs @ 12.09 hrs, Volume-- 641 cf, Depth= 2.87 1 Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" ' Area(so CN Description 2,681 98 Roofs,HSG D 2,681 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, t t ryx Proposed Condition Watershed Analysis.-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3:10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD4010.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 27 Summary for Subcatchment 25S: PR-1/4 BLD 7 Runoff = 0.15 cfs® 12.09 hrs, Volume= 532 cf, Depth= 2.87" Runoff by SCS TR-20 method,UH--SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(so CN Description 2,226 98 Roofs,HSG D Z226 100.00%Impervious Area, Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, k Proposed Condition Watershed Analysis-Revised June 27,2018-First Street Traders Wa P Y / Y Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD&10.00-20 s/n 06611 m 2017 HydroCAD Software Solutions LLC Page 28 Summary for Subcatchment 26S: PR-TRADERSa Runoff = 0.08 cfs @ 12.10 hrs, Volume= 245 cf, Depth= 1.14" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall--3.10" Ar_ea(sf) CN Description ' 2,581 77 Woods,Good,HSG D 2,581 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.2 60 0.3300 0.46 Sheet Flow, ' Grass:Short n=0.150 P2=3.10" 2.2 60 Total, Increased to minimum Tc=6.0 min i 1 . Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_RI Type I1124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 14ydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Pam 29 - Summary for Subcatchment 27S: PR NW 3/4 ' Runoff = 0.30 cis @ 12.09 hrs, Volume-- 1,064 cf, Depth= 2.87" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 2 yr Rainfall=3.10" Area(sf) CN Description ' 4,452 98 Roofs,HSG D 4,452 100.00%Impervious Area Tc Length Slope Velocity Capacity Description t (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed RI Type III 24-hr 2 yr Rainfall=3.10" 1 Prepared by Williams&Sparages Printed 7/1/2018 H.ydroCAD010.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Page 30 Summary for Pond IP: Cultec 100HD Subsurface Structure Inflow Area= 4,452 sf 100.00%Impery p Impervious, Inflow Depth= 2.87' for 2 yr event - Inflow = 0.31 cfs @ 12.01 hrs, Volume= 1,064 cf Outflow = 0.00 cfs @ 7.55 hrs, Volume= 272 cf, Atten=99%, Lag=0.0 min Discarded= 0.00 cfs @ 7.55 hrs, Volume= 272 cf Routing by Dyn-Stor-Ind method,Time Span=0.0040.00 hrs,dt=0.05 hrs/3 ' Peak Elev=113.W @ 24.05 hrs Surf.Area=969 sf Storage=908 cf t Plug-Flow detention time=(not calculated:outflow precedes inflow) Center-of-Mass det.time=522.2 min(1,279.3-757.1) Volume Invert Avail Storage Storage Description 11A 111A6' 1,967 cf 15.50'W x 62.50'L x 5.54'H Field A ' 5,368 cf Overall-450 cf Embedded=4,918 cf x 40.0%Voids #2A 115A6' 450 cf Cultec C-1WHD x 32 Inside#1 Effective Size=32.1"W x 12.0"H=>1.86 sf x 7.501=14.0 cf ' Overall Size=36.0"W x 12.5"H x 8.WL with 0.50'Overlap Row Length Adjustment--+0.50'x 1.86 sf x 4 rows 2,418 cf Total Available Storage ' Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 111.46' 0.090 irou Exfiltration over Surface area Discarded OutFlow Max=0.00 cfs @ 7.55 hrs HW=111.52' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.00 cfs) t } Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_111 Type III 24-hr 2 yr Rainfall=3.1 0" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Pag 31 Pond 1P: Cultec IOOHD Subsurface Structure-Chamber Wizard Field A Chamber Model=Cultec C-100HD(Cultec Contactor®100HD) Effective Size=32.1"W x 12.0"H=>1.86 sf x 7.501L=14.0 cf Overall Size=36.0"W x 12.5"H x 8.001 with 0.50'Overlap Row Length.Adjustment--+0.50'x 1.86 sf x 4 rows ' 36.0"Wide+6.0"Spacing=42.0"C-C Row Spacing 8 Chambers/Row x 7.50'Long+0.50'Row Adjustment=60.50'Row Length+12.0"End Stone x 2=62.50'Base Length 4 Rows x 36.0"Wide+6.0"Spacing x 3+12.0"Side Stone x 2=15.50'Base Width 48.0"Base+12.5"Chamber Height+6.0"Cover=5.54'Field Height 32 Chambers x 14.0 cf +0.50'Row Adjustment x 1.86 sf x 4 Rows=450.5 cf Chamber Storage 5,368.5 cf Field-450.5 cf Chambers=4,918.0 cf Stone x 40.0%Voids=1,967.2 cf Stone Storage ' Chamber Storage+Stone Storage=2,417.7 cf=0.056 of Overall Storage Efficiency=45.0% Overall System Size=62.50'x 15.50'x 5.54' . 32 Chambers 198.8 cy Field 182.1 cy Stone w - Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD@ 10.00-20 s/n 06611 02017 H.ydroCAD Software Solutions LLC Page 32 Summary for Pond 2P: Cultec 330XLD Subsurface Structure Inflow Area= 45,519 sf, 81.67%Impervious, Inflow Depth= 0.92" for 2 yr event Inflow = 0.99 cfs @ 12.09 hrs, Volume= 3,502 cf Outflow = 0.00 cfs @ 9.05 hrs, Volume-- 543 cf,.Atten=100%, Lag=0.0 min Discarded = 0.00 cfs @ 9.05 hrs, Volume= 543 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=107.00'@24.79hrs Surf.Area=2,102 sf Storage=3,190 cf Plug-Flow detention time=765.4 min calculated for 543 cf(16%of inflow) Center-of-Mass det.time--533.0 min(1,368.0-835.1) Volume Invert Avail Storage Storage Description M 103.21' 4,722 cf 35.33'W x 59.50'L x 7.04'H Field A 14,804 cf Overall-2,999 cf Embedded=11,805 cf x 40.0%Voids #2A 107.21' 2,999 cf Cultec R-330XL x 56 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adiustment=+1.50'x 7.45 sf x 7 rows 7,721 cf Total Available Storage Storage-Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 103.21' 0.090 hVhr Exfiltration over Surface area #2 Primary 107.75' 8.0" Round Culvert X 2.00 L=54.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=107.75'/107.00' S=0.0139'/' Cc=0.900 n=0.010, Flow Area--0.35 sf Discarded Outflow Max=0.00 cfs @ 9.05 hrs HW=103.28' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow Max=0.00 cfs @ 0.00 hrs HW=103.21' TW=0.00' {Dynamic Tailwater) t-2=Culvert (Controls 0.00 cfs) Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pale 33 Pond 2P. Cultec 330XLD Subsurface Structure-Chamber Wizard Field A '. Chamber Model=Cultec R-330XL(Cultec Recharger®330XL-DISCONTINUED,Use R-330XLHD for new designs) Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.591,with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows ' 52.0"Wide+6.0"Spacing-58.0"C-C Row Spacing 8 Chambers/Row x 7.W Long+1.50'Row Adjustment=57.50'Row Length+12.0"End Stone x 2=59.50'Base Length ' 7 Rows x 52.0"Wide+6.0"Spacing x 6+12.0"Side Stone x 2=35.33'Base Width 48.0"Base+30.5"Chamber Height+6.0"Cover=7.04'Field Height 56 Chambers x 52.2 cf +1.50'Row Adjustment x 7.45 sf x 7 Rows=2,999.0 cf Chamber Storage 14,803.9 cf Field-2,999.0 cf Chambers=11,804.9 cf Stone x 40.0%Voids=4,722.0 cf Stone Storage Chamber Storage+Stone Storage=7,721.0 cf=0.177 of Overall Storage_Efficiency=52.2 Overall System Size=59.50'x 35.33'x 7.04' 56 Chambers 548.3 cy Field 437.2 cy Stone i 1 v 1 _ Proposed Condition Watershed Analysis-Revised June 27 2018 First Street Trad Wa y a P Y T / y Proposed_R1 Type Ili 24-hr 2 yr Rainfall=3.10" 1 Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 34 Summary for Pond 3P:Cultec 330XLD Subsurface Structure 1 Inflow Area- 28,979 sf, 88.19%Impervious, Inflow Depth= 2.65 for 2 yr event Inflow = 1.87 cfs @ 12.09 hrs, Volume= 6,389 cf 1 Outflow = 0.02 cfs @ 21.80 hrs, Volume= 852 cf, Atten=99%, Lag=583.0 min Discarded= 0.00 cfs @ 6.40 hrs, Volume= 589 cf Primary = 0.02 cfs @ 21.80 hrs, Volume= 263 cf 1 Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=108.38'@ 21.80 hrs Surf.Area=2,102 sf Storage=5,827 cf Plug-Flow detention time--788.5 min calculated for 852 cf(13%of inflow) Center-of-Mass det.time--526.6 min(1,300.2-773.7) Volume Invert Avail.Storage Storage Description #lA 102.96' 4,722 cf 35.33W x 59.5011,x 7.04'H Field A 14,804 cf Overall-Z999 cf Embedded=11,805 cf x 40.0%Voids #2A 106.96' 2,999 cf Cultec R-330XLHD x 56 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size--52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment=+1.50'x 7.45 sf x 7 rows 1 7,721 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 102.96 0.090 in/hr Exfiltration over Surface area #2 Primary 108.33' 8.0" Round Culvert X 2.00 L=38.0' CPP,square edge headwall, Ke=015W ' Inlet/Outlet Invert=108.33'/107.95' S=0.0100'/' Cc=0.900 n--0.010, Flow Area--0.35 sf Discarded Outflow Max=0.00 cfs @ 6.40 hrs HW=103.03' (Free Discharge) ' t-1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFow Max=0.02 cfs @ 21.80 hrs HW=108.38' TW=106.76'. (Dynamic Tailwater) t--2=Culvert (Inlet Controls 0.02 cfs @ 0.76 fps) 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed RI Type III 24-hr 2 yr Rainfaii=3.10" Prepared by Williams&Sparages Printed 7/1/2018 `. HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Pa e�35 Pond 3P: Cultec 330XLD Subsurface Structure-Chamber Wizard Field A Chamber Model=Cultec R-330XLHD(Cultec Recharger®330XLHD) Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf I Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows I52.0"Wide+6.0"Spacing=58.0"C-C Row Spacing 8 Chambers/Row x 7.00'Long+1.50'Row Adjustment=57.50'Row Length+12.0"End Stone x 2=59.50'Base Length I 7 Rows x 52.0"Wide+6.0"Spacing x 6+12.0"Side Stone x 2=35.33'Base Width 48.0"Base+30.5"Chamber Height+6.0"Cover=7.04'Field Height 56 Chambers x 52.2 cf +1.50'Row Adjustment x 7.45 sf x 7 Rows=2,999.0 cf Chamber Storage I1003.9 cf Field-2,999.0 cf Chambers=11,804.9 cf Stone x 40.0%Voids=4,722.0 cf Stone Storage Chamber Storage+Stone Storage=7,721.0 cf=0.177 of Overall Storage Efficiency=52.2% Overall System Size=59.50',x 35.33'x 7.04' I56 Chambers 548.3 cy Field 437.2 cy Stone vaum Exam I t s i I 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed R1 Type 11124-hr 2 yr Rainfa11=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 36 Summary for Pond 4P:Cultec 330XLD Subsurface Structure ' Inflow Area= 34,647 sf, 87.27%Im ious, Inflow Depth= 2.65" for 2 event Pam' P Yr Inflow = 2.20 cfs @ 12.10 hrs, Volume= 7,641 cf Outflow = 0.11 cfs @ 14.53 hrs, Volume= 2,315 cf, Atten=95%, Lag=146.2 min Discarded= 0.00 cfs @ 6.05 hrs,'Volume= 592 cf Primary = 0.10 cfs @ 14.53 hrs, Volume= 1,723 cf 1 Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=102.12'@ 14.53 hrs Surf.Area=2,102 sf Storage=5,731 cf Plug-Flow detention time=496.3 min calculated for 2,312 cf(30%of inflow) Center-of-Mass det.time=335.1 min(1,109.4-774.2) Volume Invert Avail Storage Storage Description #1A 96.76' 4,722 cf 35.33W x 59.50'L x 7.04'H Field A 14,804 cf Overall-2,999 cf Embedded=11,805 cf x 40.0%Voids #2A 100.76' 2,999 cf Cultec R-330XLHD x 56 Inside#1 Effective Size--47.8"W x 30.0"H=>7.45 sf x 7.WL=SZ2 cf Overall Size--52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows ' 7,721 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 96.76' 0.090 irVhr Exfiltration over Surface area #2 Primary 102.W 8.0" Round Culvert X 2.00 L=34A' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=102.00'/101.66' S=0.0100'/' Cc=0.900 n=0.010, Flow Area=0.35 sf Discarded OutFow Max=0.00 cfs @ 6.05 hrs HW=96.83' (Free Discharge) ' L3=Exfiltration (Exfiltration Controls.0.00 cfs) Primary Outflow Max=0.10 cfs @ 14.53 hrs HW=102.12' TW=0.00' (Dynamic Tailwater) t-2=Culvert (Inlet Controls 0.10 cfs @ 1.19 fps) ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfatl=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 37 Pond 4P: Cultec 330XLD Subsurface Structure-Chamber Wizard Field A Chamber Model=Cultec R-330XLHD(Cultec Recharger®330XLHD) Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.5VL with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows 52.0"Wide+6.0"Spacing=58.0"C-C Row Spacing 8 Chambers Row x 7.00'Lon +1 'Row Adjustment 7 'R w Len +12.0"End'Stone x 2= '/ g .50 o d�ustment 5 .50 o Length 59.50 Base Length 7 Rows x 52.0"Wide+6.0"Spacing x 6+12.0"Side Stone x 2=35.33'Base Width ' 48.0"Base+30.5"Chamber Height+6.0"Cover=7.04'Field Height 56 Chambers x 52.2 cf +1.50'Row Adjustment x 7.45 sf x 7 Rows=2,999.0 cf Chamber Storage 14,803.9 cf Field-2,999.0 cf Chambers-11,804.9 cf Stone x 40.0%Voids=4,722.0 cf Stone Storage ' Chamber Storage+Stone Storage=7,721.0 cf=0.177 of Overall Storage Efficiency=52.2% Overall System Size=59.50'x 35.33'x 7.04' 56 Chambers 548.3 cy Field 437.2 cy Stone i E 1 i F . r .Proposed Condition Watershed Analysis Revised June 27,2018-First Street/Traders Way Proposed_R1 Type H124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 ._ HydroCAD610.00-20 sjn 06611 ©2017 HydroCAD Software Solutions LLC Pam Summary for Pond SP: Cultec 330XLD Subsurface Structure IInflow Area= 31,120 sf, 69.17%Impervious, Inflow Depth�= 2 .30" for 2 Yrevent Inflow = 1.83 cfs @ 12.09 hrs, Volume= 5,973 cf Outflow = 0.00 cfs @ 8.25 hrs, Volume= 599 cf, Atten=100%, Lag=0.0 min Discarded= 0.00 cfs @ 8.25 hrs, Volume= 599 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method,Time Span=0.0040.00 hrs,dt=0.05 hrs 13 Peak Elev=108.04'@ 24.12 hrs Surf.Area=2,260 sf Storage=5,644 cf Plug-Flow detention time=(not calculated:outflow precedes inflow) Center-of-Mass det.time=545.9 min(1,340.7-794.9) . Volume Invert Avail Storage Storage Description ' #1A 102.96' 5,097 cf 20.83'W x 108.50'L x 7.04'H Field A 15,917 cf Overall-3,174 cf Embedded=12,743 cf x 40.0%Voids #2A 106.96' 3,174 cf Cultec R-330XLHD x 60 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 4 rows ' 8,271 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 102.96' 0.090 in/hr Exfiltration over Surface area #2 Primary 108.50' 12.0" Round Culvert L=8.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=108.50'/108.25' S=0.0313'/' Cc=0.900 n=0.010, Flow Area=0.79 sf Discarded OutFow Max=0.00 cfs @ 8.25 hrs HW=103.03' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow Max=0.00 cfs @ 0.00 hrs HW=102.96' TW=O.W .(Dynamic Tailwater) UL=Culvert (Controls 0.00 cfs) 1 y 1 1 r I Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Po Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Page 39 Pond 5P: Cultec 330XLD Subsurface Structure-Chamber Wizard Field A Chamber Model=Cultec R-330XLHD(Cultec Recharger®330XLHD) Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 4 rows 52.0"Wide+6.0"Spacing=58.0"C-C Row Spacing 15 Chambers/Row x 7.00'Long+1.50'Row Adjustment=106.50'Row Length+12.0"End Stone x 2=108.50'Base Length 4 Rows x 52.0"Wide+6.0"Spacing x 3+12.0"Side Stone x 2=20.83'Base Width 48.0"Base+30.5"Chamber Height+6.0"Cover=7.04'Field Height 60 Chambers x 52.2 cf +1.50'Row Adjustment x 7.45 sf x 4 Rows=3,174.1 cf Chamber Storage 15,917.1 cf Field-3,174.1 cf Chambers=12,743.0 cf Stone x 40.0%Voids=5,0972 cf Stone Storage Chamber Storage+Stone Storage=8,271.3 cf=0.190 of Overall Storage Efficiency=52.0% Overall System Size=108.50'x 20.83'x 7.04' ' 60 Chambers 589.5 cy Field ' 472.0 cy Stone > x i Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Wa Po Ys Y Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 40 Summary for Pond 6P:Cultec 330XLD Subsurface Structure Inflow Area- 20,931 sf, 70.62%Impervious, Inflow Depth= 2.36 for 2 yr event Inflow = 1.25 cfs® 12.09 hrs, Volume= 4,111 cf Outflow = 0.00 cfs® 8.35 hrs, Volume= 504 cf, Atten--100%, Lag=0.0 min Discarded =. 0.00 cfs® 8.35 hrs, Volume= 504 cf Primary = 0.00 cfs® 0.00 hrs, Volume= 0 cf ' Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=111.97®24.11 hrs Surf.Area7-1,886 sf Storage=3,832 cf ' Plug-Flow detention time=(not calculated:outflow precedes inflow) Center-of-Mass det.time=540A min(1,331.6-791.2) Volume Invert Avail.Storage Storage Description ' #1A 107.46' 4,248 cf 25.671W x 73.50'L x 7.04'H Field A 13,284 cf Overall-Z664 cf Embedded=10,620 cf x 40.0%Voids #2A 111.46' Z664 cf Cultec R 330XLHD x 50 Inside#1 Effective Size--47,8"W x 30.0"H=>.7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 5 rows 6,912 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 107.46' 0.090 ir&Exfiltration over Surface area #2 Primary 113.67' 4.0" Round Culvert L=18.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=113.67/113.00' S=0.0372'/' Cc=0.900 n--0.010, Flow Area=0.09 sf Discarded OutFow Max=O.W cfs @ 8.35 hrs HW=107.5T (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow Max=0.W cfs®0.00 hrs HW=107.46' TW=0.00' (Dynamic Tailwater) t-2=Culvert (Controls 0.W cfs) I Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCADO 10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 41 Pond 6P:Cultec 330XLD Subsurface Structure-Chamber Wizard Field A Chamber Model=Cultec R-330XLHD(Cultec Recharger®330XLHD) Effective Size=47.8"W x 30.0"H=>7.45 sf x 7A0'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 5 rows 52.0"Wide+6.0"Spacing=58.0"C-C Row Spacing 10 Chambers/Row x 7.00'Lo +1.50'Row Adjustment=71.50'Row Length�+12.0"End Stone x 2=73.50'Base Lengt h 5 Rows x 52.0"Wide+6.0"Spacing x 4+12.0"Side Stone x 2=25.67 Base Width 48.0"Base+30.5"Chamber Height+6.0"Cover=7.04'Field Height 50 Chambers x 52.2 cf +1.50'Row.Adjustment x 7.45 sf x 5 Rows=2,663.7 cf Chamber Storage 13,284.1 cf Field-2,663.7 cf Chambers=10,620.4 cf Stone x 40.0%Voids=4,248.1 cf Stone Storage Chamber Storage+Stone Storage=6,911.9 cf=0.159 of Overall Storage Efficiency=52.0% Overall System Size=73.50'x 25.67 x 7.04' ' 50 Chambers 492.0 cy Field 393.3 cy Stone E f 1 f i , ti '9i Proposed Condition Watershed - v' 7 - p Analysis Revised June 2 ,2018 First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD910.00-20 s1n 06611 0 2017 HydroCAD Software Solutions LLC Page 42 Summary for Pond 7P:Cultec 330XLD Subsurface Structure ' Inflow Area= 30,501 sf, 70.60%Impervious, Inflow Depth= 2.34" for 2 event Pam' � P Yr Inflow = 1.81 cfs @ 12.09 hrs, Volume= 5,949 cf Outflow = 0.03 cfs @ 20.11 hrs, Volume= 1,185 cf, Atten=99%, Lag=481.0 min Discarded= 0.01 cfs @ 8.35 hrs, Volume= 720 cf Primary = 0.02 cfs @ 20.11 hrs, Volume= 465 cf ' Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=113.57 @ 20.11 hrs Surf.Area=2,707 sf Storage=5,162 cf Plug-Flow detention time=702.6 min calculated for 1,184 cf(20%of inflow) Center-of-Mass det.time=522.5 min(1,314A-791.9) - Volume Invert Avail.Storage Storage Description ' #1A 109.21' 6,070 cf 59.50'W x 45.501 x 7.04'H Field A 19,064 cf Overall-3,889 cf Embedded=15,174 cf x 40.0%Voids #2A 113.21' 3,889 cf Cultec R-330XLHD x 72 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 12 rows 9,959 cf Total Available Storage ' Storage Group A.created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 109:21' 0.090 in/hr Exfiltration over Surface area #2 Primary 113.50' 12.0" Round Culvert L=56ft CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=113.50'/113.00' S=0.0089'/' Cc=0.900 n=0.010, Flow Area--0.79 sf Discarded Outflow Max=0.01 cfs @ 8.35 hrs HW=109.28' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.01 cfs) Primary Outflow Max=0.02 cfs @ 20.11 hrs HW=113.57' TW=0.00' (Dynamic Tailwater) t-2=Culvert (Inlet Controls 0.02 cfs @ 0.90 fps) Proposed Condition Watershed Analysis-Revised une 27 2018-First Street Traders Wa P Y T / y Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Page 43 Pond 7P: Cultec 330XLD Subsurface Structure-Chamber Wizard Field A ' Chamber Model=Cultec R-330XLHD(Cultec Recharger®330XLHD) Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 12 rows 52.0"Wide+.6.0"Spacing=58.0"C-C Row Spacing I' 6 Chambers/Row x 7.00'Long+1.50 Row Adjustment=43.50'Row Length+12.0"End Stone x 2=45.50'Base Length 12 Rows x 52.0"Wide+6.0"Spacing x 11+12.0"Side Stone x 2=59.50'Base Width 48.0"Base+30.5"Chamber Height+6.0"Cover=7.04'Field Height 72 Chambers x 52.2 cf +1.50'Row Adjustment x 7.45 sf x 12 Rows=3,889.4 cf Chamber Storage 19,063.E cf Field-3,889.4 cf Chambers=15,174.1 cf Stone x 40.0%Voids=6,069.7 cf Stone Storage Chamber Storage+Stone Storage=9,959.1 cf=0.229 of Overall Storage Efficiency=52.2% Overall System Size=45.50'x 59.50'x 7.04' 72 Chambers 706.1 cy Field 562.0 cy Stone Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_RI Type Ili 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Page 44 Summary for Pond 8P: Existing BVW Inflow Area= 173, 0sf, 54.24 Impervious, Inflow Depth- 2 0T' for 2 yr event Inflow = 7.61 cfs @ 12.12 hrs, Volume= 29,919 cf Outflow = 7.51 cfs @ 12.14 hrs, Volume= 29,919 cf, Atben=l%, Lag--M min Discarded = 0.00 cfs @ 12.14 hrs, Volume-- 6 cf Primary = 7.51 cfs @ 12.14 hrs, Volume= 29,913 cf ' Routing by Dyn-Stor-Ind method,Time Span=0.0040.00 hrs,dt=0.05 hrs/3 Peak Elev=109.43'@ 12.14 hrs Surf.Area=744 sf Storage=209 cf Plug-Flow detention time=0.2 min calculated for 29,882 cf(100%of inflow) Center-of-Mass det.time=0.2 min(802.5-802.3) Volume Invert Avail Storage Storage Description #1 108.45' 2,278 cf Custom Stage Data(Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) 1cubic-feet) 108.45 0 0 0 109.00 100 27 27 110.00 1,600 850 877 110.50 4,000 1,400 2,278 Device Routing Invert Outlet Devices #1 Primary 108.45' 30.0" Round Culvert L=118.0' RCP,groove end projecting, Ke=0.200 Inlet/Outlet Invert--108.45'/94.00',S=0.1225'/' Cc=0.900 n=0.011, Flow Area--4.91 sf #2 Discarded 108.45' 0.090 in/hr Exfiltration over Surface area Discarded Outflow Max--0.00 cfs @ 12.14 hrs HW=109.42' (Free Discharge) t-2=Exfiltration.(Exfiltration Controls 0.00 cfs) Primary Outflow Max=7.41 cfs @ 12.14 hrs HW=109.42' TW=O.00' (Dynamic Tailwaber) t 1=Culvert (Inlet Controls 7.41 cfs @ 4.20 fps) Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed-RI Type II124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD.Software Solutions LLC Pam Summary for Pond 9P:Cultec 330XLD Subsurface Structure ' Inflow Area= 25,810 sf, 80.29%Impervious, Inflow Depth= 2.45" for 2 Yr event Inflow = 1.59 cfs @ 12.09 hrs, Volume= 5,263 cf Outflow = 0.01 cfs @ 8.30 hrs, Volume= 691 cf, Atten=100%, Lag=0.0 min Discarded = 0.01 cfs @ 8.30 hrs, Volume= 691 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf ' Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=116.77'@ 24.11 hrs Sur£Area=2,616 sf Storage=4,883 cf ' Plug-Flow detention time=782.7 min calculated for 691 cf(13%of Mow). Center-of-Mass det.time=556.6 min(1,344.8-788.2) Volume Invert AvaiI.Storage Storage Description #1A 112.40 5,864 cf 49.831W x 52.5011.x 7.04'H Field A 18,423 cf Overall-3,763 cf Embedded=14,660 cf x 40.0%Voids #2A 116.46' 3,763 cf Cultec R-330XLHD x 70 Inside#1 ' Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=522 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment--+1.50'°x 7.45 sf x 10 rows 9,627 cf Total Available Storage Storage Group A created with Chamber Wizard ' Device Routing Invert Outlet Devices #1 Discarded 112.46' 0.090 ir%hr Exfiltration over Surface area #2 Primary 119.17 4.0"-Round Culvert L=32.V CPP,square edge headwall, Ke=0.5W 1plet/,Outlet Invert=119.17/118.84' S=0.0102'/' Cc=0.900 ' n=:0.010, Flow Area--0.09 sf Discarded Outflow Max=0.01 cfs 6 8.30 hrs HW=112.53' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.01 cfs) ' Prima Outflow Max=0.00 cfs @ 0.00 hrs HW=112.46' TW=0.00' (Dynamic Tailwater I'S' �Yn ) L2=Culvert (Controls 0.00 cfs) t _ .. F , ProposedCondition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed R1 Type 17124-hr 2 yr Rainfall=3.10" Prepared b Williams&S ara es Printed 7 p y p g /1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC pa�46 Pond 9P:Cultec 330XLD Subsurface Structure Chamber Wizard Field A Chamber Model=Cultec R-330XLHD(Cultec RechargerO 330XLHD) Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00'L=52-2 cf ' Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 10 rows ' 52.0"Wide+6.0"Spacing=58.0"C-C Row Spacing 7 Chambers/Row x 7A0'Long+1.50'Row Adjustment=50.50'Row Length+12.0"End Stone x 2=52.50'Base Length ' 10 Rows x 52.0"Wide+6.0"Spacing x 9+12 V'Side Stone x 2=49.83'Base Width 48.0"Base+30.5"Chamber Height+6.0"Cover=7.04'Field Height 70 Chambers x 52.2 cf +1.50'Row Adjustment x 7.45 sf x 10 Rows=3,769 8 cf Chamber Storage 18,422.8 cf Field-3,762.8 cf Chambers=14,660.0 cf Stone x 40.0`Yo Voids=5,864.0 cf Stone Storage Chamber Storage+Stone Storage=9,626.8 cf=0.221 of Overall Storage Efficiency=52.3% Overall System Size=52.50'x 49.83'x 7.04' 70 Chambers 682.3 cy Field 543.0 cy Stone { . f 3 �r Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way. Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 sJn 06611 ©2017 HydroCAD Software Solutions LLC Page 47 Summary for Pond 28P: Cultec 10OHD Subsurface Structure Inflow Area= 4,452 sf,100.00%Impervious, Inflow Depth= 2.87' for 2 Yrevent Inflow 0.30 cfs® 12.09 hrs, Volume= 1,064 cf Outflow = 0.00 cfs Q 8.90 hrs, Volume= 405 cf, Atten=99%, Lag=0.0 min Discarded= 0.00 cfs @ 8.90 hrs, Volume-- 405 cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=111.88'@ 23.09 hrs Sur£Area=1,470 sf Storage=835 cf Plug-Flow detention time=694.6 min calculated for 405 cf(38%of inflow) ' Center-of-Mass det.time=541.3 min(1,298.3-757.1) Volume Invert AvailStorage Storage Description M 110.46' Z989 cf 12.00'W x 122.50'L x 5.54'H Field A 8,146 cf Overall-673 cf Embedded=7,473 cf x 40.0%Voids #2A 114.46' 673 cf Cultec C-10011D x 48 Inside#1 Effective Size=32.1"W x 12.0"H=>1.86 sf x 7.50%=14.0 cf Overall Size=36.0"W x 12.5"H x 8.00%with 0.50'Overlap Row Length Adjustment--+0.50'x 1.86 sf x 3 rows 3,662 cf Total Available Storage ' Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 110.46' 0.090 irVhr Exfiltration over Surface area Discarded Outflow Max=0.00 cfs®8.90 hrs HW=110.52' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.00 cfs) ' F Proposed Condition Watershed Analysis Rev' June 27 0 p y used J ,2 18 First Street/Traders Way Proposed_R1 Type 11124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Pam Pond 28P:Cultec 100HD Subsurface Structure-Chamber Wizard Field A 1 Chamber Model=Cultec C-100HD Cultec Conta o 0( ct r®1 OHD) Effective Size=32.1"W x 12.0"H=>1.86 sf x 7.501=14.0 cf Overall Size=36.0"W x 12.5"H x 8.001 with 0.50'Overlap Row Length Adjustment--+0.50'x 1.86 sf x 3 rows 36.0"Wide+6.0"Spacing=42.0"C-C Row Spacing 16 Chambers/Row x 7.50'Long+0.50'Row Adjustment=120.50'Row Length+12.0"End Stone x 2=122.50'Base Length ' 3 Rows x 36.0"Wide+6.0"Spacing x 2+12.0"Side Stone x 2=12.00'Base Width 48.0"Base+12.5"Chamber Height+6.0"Cover=5.54'Field Height ' 48 Chambers x 14.0 cf +0.50'Row Adjustment x 1.86 sf x 3 Rows=672.9 cf Chamber Storage 8,146.3 cf Field-672.9 cf Chambers=7,473.3 cf Stone x 40.0%Voids=2,989.3 cf Stone Storage Chamber Storage+Stone Storage=3,662.3 cf=0.084 of Overall Storage Efficiency=45.0 Overall System Size=122.50'x 12.00'x 5.54' 48 Chambers 301.7 cy Field 276.8 cy Stone Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Page 49 Summary for Link 1L: Runoff towards Traders Way drainage system Inflow Area= 14,832 sf, 13.64%Impervious, Inflow Depth= 1.46" for 2 yr event Inflow 0.57 cfs® 12.09 hrs, Volume= 11805 cf Primary 0.57 cfs @ 12.09 hrs, Volume= 1,805 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span--0.00-40.00 hrs,dt=0.05 hrs t f; 1 Proposed Condition Watershed Analysis-Revised June 27,2018 First Street/Traders Way Y Proposed—RI Type III24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HpdroCAD Software Solutions,LLC PaZ 50 Summary for Link 2L:Runoff via existing 30"RCP Culvert Inflow Area= 173,380 sf, 54.24%Impervious, Inflow Depth= 2.07" for 2 event ,38 pery p yr Inflow - 7.51 cfs® 12.14 hrs, Volume= 29,913 cf Primary = 7.51 cfs O 12.14 hrs, Volume= 29,913 cf, Atten=0%, Lag=0.0 min Primary outflow—Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs 1 I t Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type III 24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 51 Summary for Link 3L:Flow towards First Street ' Inflow Area= 84,720 sf, 61.00%Impervious, Inflow Depth= 0.84" for 2 yr event Inflow 1.84 cfs 11 12.09 hrs, Volume= 5,953 cf Primary 1.84 cfs® 12.09 hrs, Volume= 5,953 cf, Atten=0%, Lag=0.0 min . Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs 1 ' Proposed Condition Watershed Anal sis-Revised June 27 2018-First Street Traders Wa P� Y J / Y Proposed R1 Type III,24-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Pam 52 Summary for Link 4L:Flow to City of Salem.Conservation Land ' Inflow Area= 1 f 4 5,941 s, 61.68%Impervious, Inflow Depth= 1.15" for 2 yr event Inflow = 9.74 cfs @ 12.12 hrs, Volume-- 39,859 cf ' Primary = 9.74 cfs O 12.12 hrs, Volume= 39,859 cf, Atten=0%, .Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs w ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24 hr 2 yr Rainfall=3.10" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 H droCAD Software Solutions LLC PaU 53 Summary for Link 5L:Flow to the east Inflow Area= 27,834 sf, 66.30%Impervious, Inflow Depth= 2.29" for 2 yr event Inflow = 1.59 cfs @ 12.09 hrs, Volume= 5,311 cf Primary = 1.59 cfs @ 12.09 hrs, Volume= 5,311 cf, Atten=0%, Lag=0.0 min Primary outflow—Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs Proposed Condition Watershed Analysis-Revised June 27 2018-First Street .Traders Wa I'O Y T / Y Proposed_R1 Type III24-hr 2 yr Rainfall=3.10" 1 Prepared by Williams&Sparages Printed 7/1/2018 H,ydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pale 54 Summary for Link 6L:Total flow from within limit of watershed analysis Inflow Area= 443,775 sf, 61.97%Impervious, Inflow Depth= 1.22" for 2 yr event Inflow = 11.26 cfs® 12.11 hrs, Volume= 45,169 cf ' Primary = 11.26 cfs @ 12.11 hrs, Volume= 45,169 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type 11124-hr 2 yr Rainfall=3.10" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pam Summary for Link M Proposed Drain Line Inflow Area= 108,362 sf, 72-50%Impervious, Inflow Depth= 0.05" for 2 yr event Inflow 0.02 cfs @ 20.11 hrs, Volume= 465 cf Primary = 0.02 cfs @ 20.11 hrs, Volume= 465 cf, Atten=0%, Lag--0.0 min Primary outflow=Inflow,Time Span--0.00-40.00 hrs,dt=0.05 hrs M 1 ✓ i Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 10 yr Rainfa11=4.50" Prepared by Williams&Sparages Printed 7/1/2018 '. HydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Laol Summary for Subcatchment 1S: EX-CB—R Runoff = 5.35 cfs® 12.12 hrs,'Volume= 20,227 cf, Depth= 3.92" ' Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description ' 23,719 98 Roofs,HSG D 28,112 98 Paved parking,HSG D 8,545 80 >75%Grass cover,Good,HSG D ' 1,469 77 Woods,Good,HSG D 61,845 95 Weighted Average 10,014 16.19%Pervious Area 51,831 83.81%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) . (ft/ft) (ft/sec) (cfs) . ' 8.7 60 0.0100 0.11 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.5 85 0.0190 2.80 Shallow Concentrated Flow, Paved Kv=20.3 fps 9.2 145 Total Summary for Subcatchment 2S:PR-CULVERT_R ' Runoff = 3.63 cfs® 12.20 hrs, Volume= 14,739 cf, Depth= 2.55" ' Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 33,000 77 Woods,Good,HSG D 2,936 98 Paved parking,HSG D 28,532 80 >75%Grass cover,Good,HSG D ' 4,945 98 Roofs,HSG D 69,413 81 Weighted Average 61,532 88.65%Pervious Area 7,881 11.35%Impervious Area Tc .Length Slope Velocity Capacity Description _(min) (feet) (ft/ft) (ft/sec) (cfs) 9.6 100 0.1560 0.17 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.6 125 0.0500 3.60 Shallow Concentrated Flow, Unpaved Kv=16.1 fps ' 4.3 390 0.0090 1.53 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 14.5 615 Total tProposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed R1 Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 3S: PR-TRADERSb ' Runoff = 0.88 cfs® 12.09 hrs Volume= .2 783 cf, Dep th= 2.73" Runoff by SC5 TR-20 method,UH--SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description ' 10,228 80 >75%Grass cover,Good,HSG D Z023 98 Paved parking,HSG D 12,251 83 Weighted Average ' 10,228 83.49%Pervious Area 2,023 16.51%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec). (cfs) 2.2 60 0.3300 0.46 Sheet Flow, Grass:Short n=0.150 P2=3.10" ' 2.2 60 Total, Increased to minimum Tc-6.0 min Summary for Subcatchment 4S: PR-PARK Runoff = 1.77 cfs @ 12.09 hrs, Volume-- 6,148 cf, Depth= 4.04" Runoff by SC5 TR-20 method,UH=SC:S,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description ' - 16,283. 98 Paved parking,HSG D 1,996 80 >75%Grass cover,Good,HSG D 18,279 96 Weighted Average 1,996 10.92%Pervious Area . 16,283 89.08%Impervious Area Tc. Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cis) 0.3 25 0.0400 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" ' 1.0 255 0.0400 4.06 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.3 280 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment SS:PR-FIRST_R Runoff _ Z61 cfs® 12.09 hrs, Volume= . 8,314 cf, Depth= 2.91" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.5W' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed-RI Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC EW 33 Area(sf) CN Description ' 2,681 98 Roofs,HSG D 6,917 98 Paved parking,HSG D 24,696 80 >75%Grass cover,Good,HSG D 34,294 85 Weighted Average 24,696 72.01%Pervious Area 91598 27.99%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.4 40 0.1100 0.28 Sheet Flow, Grass:Short n=0.150 P2=3.10" 1.9 290 0.0250 2.55 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 4.3 330 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 6S:PR-EAST Runoff = 0.71 cfs® 12.09 hrs, Volume-- Z243 cf, Depth= 2.82" Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span-0.0040.00 hrs,dt=0.05 hrs ' Type III 24-hr 10 yr Rainfall=4M" Area(sf) CN Description 1,500 77 Woods,Good,HSG D 5,885 80 >75%Grass cover,Good,HSG D 2,170 98 Paved parkin,HSG D 9,555 84 Weighted Average ' 7,385 77.29%Pervious Area 2,170 22.71%Impervious Area Tc Length Slope Velocity Capacity Description ' (min) (W) (II/II) (II/sec) {cfs) 3.5 50 0.0700 0.24 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.3 100 0.1200 5.58 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 3.8 150 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 7S:PR-1R Runoff 2.18 cfs® 12.09 hrs, Volume= 7,376 cf, Depth= 3.82" -Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfa1l=4.50" 1 Proposed-Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20.s/n 06611 0 2017 HydroCAD Software Solutions LLC Page 4 Area(sf) CN Description 14,215 98 Paved parking,HSG D 4;545 80 >75%Grass cover,Good,HSG D 4,440 98 Roofs,HSG D 23,200 94 Weighted Average 4,545 19.59%Pervious Area 18,655 80.41%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Sheet Flow,1 0.5 25 0.0100 0.78 Smooth surfaces n=0.011 P2=3.10" 1.1 130 0.0100 2.03 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.6 155 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 8S:PR 1/2 BLDG 1 Runoff = 0.44 cis @ 12.09 hrs, Volume= 1,592 cf, Depth= 4.26" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 4,452 98 Roofs,HSG D t 4,452 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) . (cfs) 6.0 Direct Entry, Summary for Subcatchment 9S:PR-2R Runoff = 1.91 cfs @ 12.09 hrs, Volume= 6,565 cf, Depth= 3.92" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 1602 98 Paved parking,HSG D 3,422 80 >75%Grass cover,Good,HSG D 20,074 95 Weighted Average 3,422 17.05%Pervious Area 16,652 82.95%Impervious.Area { 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type 11124-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 sln 06611 02017 HydroCAD Software Solutions LLC Page 5 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.3 25 0.0200 0.13 Sheet Flow, Grass:Short n=0.150 P2=3.10" 1.0 125 0.0100 2.03 Shallow Concentrated Flow, . Paved Kv=20.3 fps 4.3 150 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 10S: PR-3R Runoff = 1.53 cfs @ 12.09 hrs, Volume= 5,111 cf, Depth= 3.71" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" " Area(sf) CN Description 11,617 98 Paved parking,HSG D 4,923 80 >75%Grass cover,Good,HSG D 16,540 93 Weighted Average 4,923 29.76%Pervious Area 11,617 70.24%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) ON 2.6 50 0.1400 0.32 Sheet Flow, Grass:Short n=0.150 P2=3.19' 1A 160 0.0090 1.93 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.0 210 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 11S:PR-BLDG 2 Runoff = 0.88 cfs® 12.09 hrs, Volume= 3,164 cf, Depth= 4.26" Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" ' Area(sf) CN Description 8,905 98 Roofs,HSG D 81905 100.00%Impervious Area Tc Length Slope Velocity Capacity Description .(min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, i 1 s Proposed Condition Watershed Analysis-Revised June 27 2018-First Street Traders Wa Po y J / y Proposed_R1 Type II124-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 12S: PR-4R Runoff = 2.23 cfs Q 12.10 hrs Volume= 7,824 cf th= 3.92" Dep 1 Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 5,363 98 Roofs,HSG D 14,148 98 Paved parking,HSG D 4,411 80 >75%Grass cover,Good,HSG D 23,922 95 Weighted Average 4,411 18.44%Pervious Area 19,511 81.56%Impervious Area ' Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) 6.3 40 0.0100 0.11 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.1 20 0.0200 2.87 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.6 175 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 7.0 235 Total Summary for Subcatchment 13S:PR-BLDG 5 Runoff 1.06 cfs @ 12.09 hrs, Volume= 3,811 cf, Depth= 4.26" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 10,725 98 Roofs,HSG D 10,725 100.00%Impervious Area i Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftJsec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 14S:GARAGES 5A&5B Runoff 0.24 cfs® 12.09 hrs, Volume— 860 cf, Depth= 4.26" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" i 1 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_Rl Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 sJn 06611 @ 2017 HydroCAD Software Solutions LLC Pa g 77 Area(sf) CN Description 2,420 98 Roofs,HSG D 2,420 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 15S:PR-SR Runoff 2.60 cfs @ 12.09 hrs, Volume= 8,615 cf, Depth= 3.60" 1 Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" ' Area(sf) CN Description 2,676 98 Roofs,HSG D 16,431 98 Paved parking,HSG D 9,593 80 >75%Grass cover,Good,HSG D 28,700 92 Weighted Average 9,5% 33.43%Pervious Area 19,107 66.57%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) ' 4.0 50 0.0500 0.21 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.1 20 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.7 190 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.8 260 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 16S.PR-6R Runoff 0.41 cfs @ 12.09 hrs, Volume= 1,332 cf, Depth= 3.30" .Runoff by SCS IR 20 method,UH=SCS,Weighted-CN,Tune.Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 2,384 98 Paved parking,HSG D 2,465 80 >75%Grass cover,Good,HSG D 4" 89 Weighted Average 2,465 50.84%Pervious Area . 1 ` Z384 49.16%Impervious Area Proposed Condition Watershed Analysis-:Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III24-hr I0 yr Rainfall=450" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 8 Tc Length Slope Velocity Capacity Description (min) .(feet) (ft/ft) (ft/sec) . (cfs) 0.3 25 0.0500 1.48 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.6 175 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.9 200 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 17S: GARAGES 6A&6B Runoff = 0.24 cfs® 12.09 hrs, Volume= 860 cf, Depth= 4.26" Runoff by SCS TR-20 method,UH-SCS,Weighted-CN,Time Span-0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(so CN Description 2,420 98 Roofs,HSG D 2,420 100.00%Impervious Area Tc Length Slope Velocity Capacity Description _(min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 18S: PR-7R Runoff = 1.16 cfs Cam? 12.09 hrs, Volume-- 3,875 cf, Depth= 3.71" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Tune Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(so CN Description 8,105 98 Paved parking,HSG D 3,736 80 >75%Grass cover,Good,HSG D 700 98 Roofs,HSG D 12,541 93 Weighted Average 3,736 29.79%Pervious Area 81805 70.21%Impervious Area Tc Length Slope Velocity Capacity Description . .dmin) (feet) (fyft) (ft/sec) (cfs) 2.9 40 0.5000 0.23 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.6 140 0.0360 3.85 Shallow Concentrated Flow, Paved Kv=20.3 fps 3.5 180 Total, Increased to minimum Tc 6.0 min Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC EqM 99 Summary for Subcatchment 19S:PR-8R Runoff 2.42 cfs® 12.09 hrs, Volume= 8,206 cf, Depth= 3.82" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type IA 24-hr 10 yr Rainfall=4.50" Area(so CN Description 13,367 98 Paved parking,HSG D Z287 80 >75%Grass cover,Good,HSG D 2,800 77 Woods,Good,HSG D 7,356 98 Roofs,HSG D 25,810 94 Weighted Average 5,087 19.71%Pervious Area 20,723 80.29%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.9 40 0.5000 0.23 Sheet Flow, Woods:Light•underbrush n=0.400 P2=3.10" 0.7 140 0.0280 3.40 Shallow Concentrated Flow, Paved Kv=20.3 fps 3.6 180 Total, Increased to minimum Tc-6.0 min Summary for Subcatchment 20S: PR-9R Runoff = 1.80 cfs® 12.09 hrs, Volume= 6,189 cf, Depth= 3.92" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span---0.00-40.00 hrs,dt=0.05 hrs ' Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CST Description ' 9,402 98 Paved parking,HSG D 3,247 80 >75%Grass cover,Good,HSG D 6,273 98 Roofs,HSG D 18,922 95 Weighted Average 3,247 17.16%Pervious Area 15,675 82.84%Impervious Area Tc Length Slope Velocity Capacity Description -(min) (feet) (ft/ft) (ft/sec) (cfs) 0..3 25 0.0330 1.25 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" '0:7 180 0.0480 4.45 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.0 205 Total, Increased to minimum Tc=6.0 min_ Proposed Condition Watershed Analysis-Revised June 27 2018-First Street Traders W Po Y 1 / ay Proposed_R1 Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Pace 10 Summary for Subcatchment 21S: PR-IOR Runoff = 0.53 cfs Cam) 12.09 hrs, Volume= 1,740 cf, DeP th= 3.50" Runoff by SCS TR-20 method,UH=8CS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 2,830 98 Paved parking,HSG D 2,414 80 >75%Grass cover,Good,HSG D 726 98 Roofs,HSG D 5,970 91 Weighted Average 2,414 40.44%Pervious Area 3,556 59.56%Impervious Area t Tc Length Slope Velocity Capacity Description fmm) (feet) (ft/ft) (ftjsec) (cfs) 0.3 25 0.0500 1.48 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.6 175 0.05W 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.9 200 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 22S:PR-11R jRunoff = 0.66 cfs® 12.09 hrs, Volume= 2,166 cf, Depth= 3.40" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 3,673 98 Paved parking,HSG D 3,257 80 >75%Grass cover,Good,HSG D 726 98 Roofs,HSG D 7,656 90 Weighted Average 3,257 42.54%Pervious Area 4,399 '57.46%Impervious Area Tc Length Slope Velocity Capacity. Description (min) (feet) (ft/ft) (ftlsec) (cfs) 0.3 25 0.0400 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.5 125 0`0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 4 0.8 150 Total, Increased to minimum Tc 6.0 min t , i r Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Y Proposed_R1 Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 4 2017 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 23S:PIS-12 Runoff = 1.72 cfs® 12.09 hrs, Volume= 5,886 cf, Depth= 3.9Z' Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description. 9,572 98 Paved parking,HSG D 3,245 80 >75%Grass cover,Good,HSG D 5,179 98 Roofs,HSG D I 17,996 95 Weighted Average 3,245 18.03%Pervious Area 14,751 81.97%Impervious Area Tc Length Slope Velocity Capacity Description Amin (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0401 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.8 205 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.1 230 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 24S:PR-1/4 BLD 6 Runoff = 0.26 cfs @ 12.09 hrs, Volume= 953 cf, Depth= 4.26" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" Area(sf) CN Description 2,681 98 Roofs,HSG D 2,681 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 25S: PR-1/4 BLD 7 Runoff 0.22 cfs® 12.09 hrs, Volume= 791 cf, Depth= 4.26" Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" g Proposed Condition Watershed Analysis-Revised June 27,2015-First Street/Traders Way Proposed_R1 Type III 24-hr 10 yr Rainfall=4.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pave 12 Area(sf) CN Description 2,226 98 Roofs,HSG D 2,226 100.00%Impervious Area I Tc Length Slope Velocity Capacity Description (nun) (feet) (ft/ft) (ftJsec) (cfs) 6.0 Direct Entry, ISummary for Subcatchment 26S:PR-TRADERSa Runoff = 0.15 cfs @ 12.09 hrs, Volume= 475 cf, Depth= 2.21" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 10 yr Rainfall=4.50" ' Area(sf) CN Description 2,581 77 Woods,Good,HSG D 2,%1 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22 60 0.3300 0.46 Sheet Flow, Grass:Short n=0.150,P2=3.10" 2.2 60 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 27S:PR NW 3/4 Runoff 0.44 cfs @ 12.09 hrs, Volume= 1,%2 cf, Depth= 4.26" Runoff b SCS TR-20 method,UH=SCS,Weighted-CN,Time S =0.00-40.00 hrs,dt=0.05 hrs Y � Pan Type III 24-hr 10 yr Rainfall=4.50" rArea(so CN Description 4,452 98 Roofs,HSG D 4,452 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Pond 1P:Cultec 100HD Subsurface Structure Inflow Area= 4,452 sf,100.00%Impervious, Inflow Depth= 4.26' for 10 yr event Inflow = 0.44 cfs @ 12.09 hrs, Volume= 1,582 cf Outflow = 0.00 cfs @ 5.60 hrs, Volume= 279 cf, Atten=100%, Lag=0.0 min Discarded= 0.00 cfs @ 5.60 hrs, Volume-- 279 cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Proposed Condition Watershed Analysis-Revised June,27,2018-First Street/Traders Way Proposed_Rl Type Ill24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Page 13 Peak Elev=115.12'@ 24.09 hrs Surf.Area=969 sf Storage=1,419 cf tPlug-Flow detention time--777.7 min calculated for 279 cf(18%of inflow) Center-of-Mass det.time=499.9 min(1,249.7-749.8) Volume Invert Avail.Storage Storage Description #1A 111.46' 1,967 cf 15.50'W x 62.50'L x 5.54'H Field A 5,368 cf Overall-450 cf Embedded=4,918 cf x 40.0%Voids I #2A 115.46' 450 cf Cultec C-10OHD x 32.Inside#1 Effective Size=32.1"W x 12.0"H=>1.86 sf x 7.501=14.0 cf Overall Size=36.0"W x 12.5"H x 8.001 with 0.50'Overlap Row Length Adjustment--+0.50'x 1.86 sf x 4 rows 2,418 cf Total Available Storage Storage Group A created with Chamber Wizard ' Device Routing Invert Outlet Devices #1 Discarded 111.46' 0.090 in/hr Exfiltration over Surface area ' ,Diiscarded Outflow Max�.00 cfs @ 5.60 hrs HW=111.52' (Free Discharge) 1 Exfiltration (Exfiltration Controls 0.00 cfs) ' Summary for Pond 2P: Cultec 330XLD Subsurface Structure Inflow Area= 45,519 sf, 81.67%Impervious, Inflow Depth= 2.29" for 10 yr event Inflow = 1.53 cfs @ 12.09 hrs, Volume= 8,695 cf Outflow = 0.27 cfs @ 13.83 hrs, Volume= 4,557 cf, Atten=82%, Lag=104.4 min Discarded = 0.00 cfs @ 7.50 hrs, Volume-- 567 cf Primary = 0.26 cfs @ 13.83 hrs, Volume= 3,990 cf 6 Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=107.95'@ 13.83 hrs Surf.Area=2,102 sf Storage=4,673 cf tPlug-Flow detention time=351.5 min calculated for 4,551 cf(52%of inflow) Center-of-Mass det:time=210.9 min(1,059.6-848.7) Volume Invert Avail.Storage Storage Description #1A 103.21' 4,722 cf 35.33'W x 59.50%x 7.04'11 Field A 14,804 cf Overall-2,999 cf Embedded-11,805 cf x 40.0%Voids #2A 107.21' 2,999 cf Cultec R-330XL x 56 Inside#1 Effective Size=47.80W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.5011,with 1.W Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows 7,721 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 103.21' 0.090 in/hr Exfiltration over Surface area #2 Primary 107.75' 8.0" Round Culvert X 2.00 L=54.0' CPP,square edge headwall, Ke=0.500 1 #4 ff ' Proposed Condition Watershed Analysis-Revised June 27 2018-First Street Traders Wa P Y 1 / Y Proposed_RI Type II124-hr 10 yr Rainfall=4.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC paw Inlet/Outlet Invert=107.75'/107.00' S=0.0139'/' Cc=0.900 n=0.010, Flow Area=0.35 sf Discarded OutFow Max=0.00 cfs @ 7.50 hrs HW=103.28' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.00 cfs) Prim Outflow Max�.26 cfs @ 13.83 hrs HW=107.95' TW=0.00' Tailwater az'Y roYn�c ) t-2=Culvert (Inlet Controls 0.26 cfs @ 1.52 fps) Summary for Pond 3P: Cultec 330XLD Subsurface Structure Inflow Area= 28,979 sf, 88.19%Impervious, Inflow Depth= 4.03" for 10 yr event . Inflow = 2.79 cfs @ 12.09 hrs, Volume= 9,730 cf Outflow = 0.40 cfs @ 12.60 hrs, Volume= 4,189 cf, Atten=86%, Lag=30.8 min Discarded= 0.00 cfs @ 4.70 hrs,.Volume= 604 cf ' Primary = 0.40 cfs @ 12.60 hrs, Volume= 3,5M cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 ' Peak Mev=108.58'@ 12.60 hrs Sur£Area=2,102 sf Storage=6,139 cf Plug-Flow detention time--358.4 min calculated for 4,183 cf(43%of inflow) Center-of-Mass det.time=224.7 min(988.9-764.1) Volume Invert Avail Storage Storage Description #1A .102.96' 4,722 cf '35.33'W x 59.50%x 7.04'H Field A 14,804 cf Overall-2,999 cf Embedded=11,805 cf x 40.0%Voids #2A 106.96' 2,999 cf Cultec R-330XLHD x 56 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows 7,721 cf Total Available Storage Storage Group A created with Chamber Wizard ' Device Routing Invert Outlet Devices #1 Discarded 102.96' 0.090 it fhr Exfiltration over Surface area ' #2 Primary 108.33' 8.0" Round Culvert X 2.00 L=38.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=108.33'/107.95' S=0.0100'/' Cc=0.900 n=0.010, Now Area=.0.35 sf tDiscarded Outflow Max=0.00 cfs @ 4.70 hrs HW=103.03' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow Max=0.40 cfs @ 12.60 hrs HW=108.58' TW=107.23' (Dynamic Tailwater) 't--2=Culvert (Inlet Controls 0.40 cfs @ 1.69 fps) i Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 10 yr Rainfall=4.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Page 15 Summary for Pond 4P. Cultec 330XLD Subsurface Structure Inflow Area= 34,647 sf, 87.27%Impervious, Inflow Depth= 4.03" for 10 yr event Inflow 3.28 cfs @ 12.10 hrs, Volume= 11,635 cf Outflow = 1.24 cfs @ 12.35 hrs, Volume= 6,306 cf, Atten=62%, Lag=15.5 min Discarded= 0.00 cfs @ 4.40 hrs, Volume= 606 cf Primary = 1.23 cfs @ 12.35 hrs, Volume= 5,699 cf Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak IIev=102.47 @ 12.35 hrs Surf.Area=2,102 sf Storage=6,283 cf Plug-;Flow detention time--281.0 min calculated for 6,3W cf(54%of inflow) Center-of-Mass det.time=166.0 min(930.7-764.7) Volume Invert Avail.Storage Storage Description #lA 96.76' 4,722 cf 35.33'W x 59.50'L x 7.04'H Field A 14,804 cf Overall-2,999 cf Embedded=11,805 cf x 40.0%Voids #2A 100.76' 2,999 cf Cultec R-330XLHD x 56 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00%=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows 7,721 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 96.76' 0.090 in/hr Exfiltration over Surface area #2 Primary 102.00' 6.0" Round Culvert X 2.00 L=34.9 CPP,square edge headwall, M=0.500 Inlet/Outlet Invert=102.00'/101.66' S=0.0100'/' Cc--0.900 n=0.010, Flow Area=0.35 sf Discarded Outflow Max=0.00 cfs @ 4.40 hrs HW=96.83' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow'Max=1.23 cfs @ 12.35 hrs HW=102.47 TW=0.00' (Dynamic Tailwater) t-2=Culvert (Inlet Controls 1.23 cis @ 2.34 fps) Summary for Pond 5P: Cultec 330XLD Subsurface Structure Inflow Area 31,120 sf, 69.17%Impervious, inflow Depth= 3.65" for 10 yr event Inflow 2:84 cfs @ 12.09 hrs, Volume= 9,475 cf Outflow = 0.16 cfs @ 13.96 hrs, Volume-- 3,234 cf, Atten=94%, Lag=112.5 min. Discarded= 0.00 cfs @ 6.60 hrs, Volume= 623 cf Primary = 0.16 cfs @ 13.96 hrs, Volume= 2,611 cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Peak IIev=108.69'@ 13.96 hrs Surf.Area=2,260 sf Storage=6,765 cf Plug Flow detention time=(not calculated:outflow precedes inflow) Center-of-Mass det.time=296.7 min(1,079.5-782.8) 1 w' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_111 Type III24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCADS 10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 16 ' Volume Invert AvailStorage Storage Description #1A 102.96' 5,097 cf 20.83'W x 108.50%x 7.04'H Field A, 15,917 cf Overall-3,174 cf Embedded=12,743 cf x 40.0%Voids #2A 106.96' 3,174 cf Cultec R-330XLHD x 60 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 4 rows 8,271 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices 411 Discarded 102.96' 0.090 in/hr Exfiltration over Surface area #2 Primary 108.50 12.0" Round Culvert L=8.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=108.50'/108.25' S=0.0313'/' Cc=0.900 n=0.010, Flow Area=0.79 sf Discarded OutFlow Max=0.00 cfs @ 6.60 hrs HW=103.03' (Free Discharge) t-1=Exfiltration (Exf ltration Controls 0.00 cfs) Primary OutFlow Max=0.16 cfs.@ 13.96 hrs HW=108.69' TW=0.00' (Dynamic Tailwater) t-2=Culvert (Inlet Controls 0.16 cfs @ 1.49 fps) Summary for Pond 6P:Cultec 330XLD Subsurface Structure Inflow Area 20,931 sf, 70.62%Impervious, Inflow Depth= 3.71" for 10 yr event Inflow 1.93 cfs @ 12.09 hrs, Volume= 6,475 cf Outflow = 0.00 cfs @ 6.70 hrs, Volume= 524 cf, Atten=100%, Lag=0.0 min Discarded 0.00 cfs @ 6.70 hrs, Volume= 524 cf Primary _ 0.00 cfs @ 0.00 hrs, Volume-- 0 cf Routing by Dyn Stor-Ind method,Time Span--0.00-40.00 firs,dt=0.05 hrs/3 Peak Elev=113.61'@ 24.13 hrs Surf.Area=1,886 sf Storage=6,176 cf Plug-Flow detention time=(not calculated:outflow precedes inflow) Center-of-Mass det.time=510.1 min(1,289.8-779.7) Volume Invert AvailStorage Storage Description #IA 107.46' 4,248 cf 25.67W x 73.50%x 7.04'H Field A 13,284 cf Overall-2,664 cf Embedded=10,620 cf is 40.0%Voids #2A 111.46' 2,664 cf Cultec R-330XLHD x 50 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00%=512 cf Overall Size--52.0"W x 30.5"H x 8.50%with 1.5V Overlap Row Length Adjustment--+1.50'x 7.45 sf x 5 rows 6,912 cf Total Available Storage Storage Group A created with-Chamber Wizard i ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD610.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 17 Device Routing Invert Outlet Devices #1 Discarded 107.46' 0.090 in/hr Exfiltration over Surface area #2 Primary 113.67, 4.0" Round Culvert L=18.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=113.67/113.00' S=0.0372'/' Cc=0.900 ' n=0.010, Flow Area=0.09 sf Discarded Outflow Max=0.00 cfs®6.70 hrs HW=107.53' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.00 cfs) ' Primary Outflow Max=0.00 cfs U 0.00 hrs HW=107.46' TW=0.00' (Dynamic Tailwater) t-2=Culvert (Controls 0.00.cfs) 1 Summary for Pond 7P: Cultec 330XLD Subsurface Structure Inflow Area= 30,501 sf, 70.60%Impervious, Inflow Depth= 3.69" for 10 yr event Inflow 2.79 cfs @ 12.09 hrs, Volume= 9,W4 cf Outflow = 0.36 cfs® 12.65 hrs, Volume= 4,612 cf, Atten=87%, Lag=33.7 min. Discarded= 0.01 cfs @ 6.70 hrs, Volume= 748 cf ' Primary = 0.36 cfs @ 12.65 hrs, Volume= 30A cf Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=113.79'®12.65 hrs Surf.Area=2,707 sf Storage='5,676 cf Plug-Flow detention time--342.6 min calculated for 4,612 cf(49%of inflow) Center-of-Mass det time=225.0 min(1,005.3-780.3) Volume Invert Avail.Storage Storage Description #IA 109.21' 6,070 cf 59.50'W x 45.50%x 7.04111 Field A 19,064 cf Overall-3,889 cf Embedded=15,174 cf x 40.0%Voids #2A 113.21' 3,W9 cf Cultec R-330XLHD x 72 Inside#1 Effective Size--47.8"W x 30.0"H=>7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 12 rows ' 9,959 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 109.21' 0.090 in/hr Exfiltration over Surface area #2 Primary 113.50' 12.0" Round Culvert .L=56.0' CPP,square edge headwall, Ke=0.500 ' Inlet/Outlet Invert=113.50'/113.00' S=0.0089'/' Cc=0.900 n=0.010, Flow Area=0.79 sf Discarded OutFow Max=0.01 cfs®6.70 hrs HW=109.28' (Free Discharge) t 1=Exfiltration (Exfiltration Controls 0.01 cfs) Primary Outflow Max--0.36 cfs @ 12.65 hrs HW=113.79' TW=0.00' (Dynamic Tailwater) ' t-2=Culvert (Inlet Controls 0.36 cfs®1.85 fps) f j Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Y Proposed RI Type 11124-hr 10 yr Rainfal&4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Pam Summary for Pond 8P:Existing BVW Inflow Area= 173,380 sf, 54.24%Impervious, Inflow Depth= 3.36" for 10 r event � � P� � P Y Inflow 12.10 cfs @ 12.12 hrs, Volume 48,531 cf Outflow = 11.90 cfs @ 12.15 hrs, Volume= 48,531 cf, Atten=2%, Lag=1.4 min Discarded= 0.00 cfs @ 12.15 hrs, Volume= 9 cf Primary = 11.89 cfs @ 12.15 hrs, Volume= 48,522 cf ' Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=109.71'@ 12.15 hrs Sur£Area=1,170 sf Storage=480 cf Plug-Flow detention time--0.3 min calculated for 48,470 cf(100%of inflow) Center-of-Mass det.time=0.3 min(791.8-791.5) Volume Invert AvailStorage Storage Description 1 #1 108.45' 2,278 cf Custom Stage Data(Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store I (feet) (sq-ft) (cubic-feet) (cubic-feet) 108.45 0 0 0 109.00 100 27 27 110.00 11600 850 877 110.50 4,000 1,400 2,278 Device Routing Invert Outlet Devices #1 Primary 108.45' 30.0" Round Culvert L=118.0' RCP,groove end projecting, Ke=0.200 i Inlet/Outlet Invert--108.45-/94.00' S=0.1225'/' Cc=0.900 n=0.011, Flow Area=4.91 sf #2 Discarded 108.45' 0.090 in/hr Exfiltration over Surface area ' Discarded OutFow Max--0.00 cfs @ 12.15 hrs HW=109.71' (Free Discharge) t-2=Exfiltration (Exfiltration Controls 0.00 cfs) Lary Outflow Max=11.82 cfs @ 12.15 hrs HW=109.71' TW=0.00' (Dynamic Tailwater) 1Culvert (Inlet Controls 11.82 cfs @ 4.77 fps) Summary for Pond 9P:Cultec 330XLD Subsurface Structure Inflow Area= 25,810 sf, 80.29%Impervious, Inflow Depth- 3.82" for 10 yr event Inflow 2.42 cfs @ 12.09 hrs, Volume= 8,206 cf Outflow = 0.01 cfs @ 6.60 hrs, Volume= 718 cf, Atten=100%, Lag=0.0 min Discarded = 0.01 cfs @ 6.60 hrs, Volume= 718 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=118.15'@ 24.12 hrs Surf.Area=Z616 sf Storage=7,799 cf Plug-Flow detention time=825.0 min calculated for 717 cf(9%of inflow) Center-of-Mass det.time=527.0 min(1,303 5-7765) tProposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_RI Type III 24-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Page 19 Volume Invert Avail.Storage Storage Description #1A 112.40 5,864 cf 49.83'W x 52.50%x 7.04'H Field A 18A23 cf Overall-3,763 cf Embedded=14,660 cf x 40.0%Voids #2A 116.40 3,763 cf Cultec R-330XLHD x 70 Inside#1 Effective Size--47.8"W x 30.0"H=>7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 10 rows 9,627 cf Total Available Storage ' Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 112.46' 0.09.0 in/hr Exfiltration over Surface area #2 Primary 119.1T 4.0" Round Culvert L=32.5' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=119.1T/118.84' S=0.0102'/' Cc=0.900 n=0.010, Flow Area--0.09 sf Discarded OutFlow Max=0.01 cfs Q 6.60 hrs HW=112.53' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.01 cfs) 1 Primary OutF low Max=0.00 cfs®0.00 hrs.HW=112.46 TW=0.00' 'c Tailwater NYC ) t--2=Culvert (Controls 0.00 cfs) Summarylor Pond 28P:Cultec 100HD Subsurface,Structure Inflow Area= 4A52 sf,100.00%Impervious, Inflow Depth= 4.26" for 10 yr event Inflow 0.44 cfs® 12.09 hrs, Volume= 1,582 cf Outflow = 0.00 cfs® 7.15 hrs, Volume= 419 cf, Atten=99%, Lag=0.0 min Discarded- 0.00 cfs® 7.15 hrs, Volume= 419.0 1 Routing by Dyn-Stor-Ind method,Time Span--0.0040.00 hrs,dt=0.05 hrs/3 Peak Mev=112.74'®24.05 hrs Surf.Area=1,470 sf 'Storage=1,339 cf Plug-Flow detention time--723.6 min calculated for 418 cf(26%of inflow) Center-of-Mass det.time=511.7 min(1,261.5-749.8) ' Volume Invert Avail.Storage Storage Description KA 110.46' 2,989 cf MOM x 1=501 x 5.54'H Field A 8,146 cf Overall-673 cf Embedded=7,473 cf x 40.0%Voids #2A 114.40 673 cf _Cultec C-100HD x 48 Inside#1 �. Effective Size=32.1"W x 12.0"H=>1.86 sf x 7.501=14.0 cf Overall Size=360W x 12.5"H x 8.001 with 0.50'Overlap Row Length Adjustment--+0.50'x 1.86 sf x 3 rows - 3,662 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert .Outlet Devices#1 Discarded 110.46' 0.090 ul/hr Exfiltration over Surface area i 1 Proposed Condition Watershed Analysis-Revised June 27 2018-Firs t Street/Traders Way Proposed_R1 Type 11124-hr 10 yr Rainfall=4.50" Prepared by Williams&Sparages Printed 7/1/2018- _ HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pa�20 Discarded OutFlow Max=0.00 cfs @ 7.15 hrs HW=110.52' (Free Discharge) L1=Wiltration (Exfiltration Controls 0.00 cfs) Summary for Link 1L:Runoff towards Traders Way drainage system Inflow Area= 14,832 sf, 13.64%Impervious, Inflow Depth= 2.64" for 10 yr event Inflow _ 1.03 cfs @ 12.09 hrs, Volume= 3,258 cf Primary 1.03 cfs @ 12.09 hrs, Volume= 3,258 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs Summary for Link 2L:Runoff via existing 30" RCP Culvert Inflow Area= 173XO sf, 54.24%Impervious, Inflow Depth= 3.36" for 10 yr event Inflow 11.89 cfs @ 12.15 hrs, Volume= 48,522 cf Primary = 11.89 cfs @ 1215 hrs, Volume= 48,522 cf, Atten=0%, Lag=0.0 min IPrimary outflow=Inflow,Tune Span=0.00-40.00 hrs,dt=0.05 hrs Summary for Link 3L:Flow towards First Street Inflow Area 84,720 sf, 61.00%Impervious, Inflow Depth= 1.99" for 10 yr event Inflow = 3.16 cfs @ 12.69 hrs, Volume-- 14,047 cf Primary = 3.10 cfs @ 12.09 hrs, Volume= 14,047 cf, Atten=0%, Lag=0.0 min Ti Primary outflow=Inflow, me Span 0.00-40.00 hrs,dt-_0.05 hrs ' Summary for Link 4L:Flow to City of Salem Conservation Land Inflow Area= 415,941 sf, 61.68%Impervious, Inflow Depth= 2.25" for 10 yr event Inflow = 15.59 cfs @ 12.12 hrs, Volume= 78,001 cf Primary = 15.59 cfs @ 12.12 hrs, Volume= 78,001 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span--0.00-40.00 hrs,dt=0.05 hrs ' Summary for Link 5L:Flow to the east 1 Inflow Area= 27AM sf, 66.30%Impervious, Inflow Depth= 3.62" for 10 yr event Inflow = 2.47 cfs @ 12.09 hrs, Volume= 8,390 cf Primary 2.47 cfs @ 42.09 hrs, Volume= 8,390 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs I Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type III 24-hr 10 yr Rainfall=4.50" I Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 s/n 06611 02017 HydroCAD Software Solutions.LLC Page 21 Summary for Link 6L:Total flow from within limit of watershed analysis Inflow Area= 443,775 sf, 61.97%Impervious, Inflow Depth= 2.34" for 10 yr event Inflow = 17.93 cfs @ 12.12 hrs, Volume= 86,391 cf Primary = 17.93 cfs® 12.12 hrs, Volume= 86,391 cf, Atten=0%, Lag=0.0 min Pr' 'Youtflow= now Time SPan=0.00-40.00 hrs dt=0.05 hrs Summary for Link 7L:Proposed Drain Line Inflow Area= 108,362 sf, 72.50%I.mpervious, Inflow Depth= 0:72" for 10 yr event Inflow 0.36 cfs @ 12.65 hrs, Volume= 6,475 cf Primary 0.36 cfs® 12.65 hrs, Volume= 6,475 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs 1 Proposed Condition Watershed Analysis-Revised June 27 2018-first Street Traders Wa Po Ys J / Y Proposed_R1 Type 11124-hr 100 yr Rainfall=6.S0" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 H.ydroCAD Software Solutions LLC Pare` Summary for Subcatchment 1S: EX-CB_R Runoff = 7.88 cfs® 12.12 hrs, Volume= 30,451 cf, Depth= 5.91" Runoff by SCS TR-20 method,UH=aCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(so CN Description 23,719 98 Roofs,HSG D 28,112 98 Paved parking,HSG D 8,545 80 >75%Grass cover,Good,HSG D 109 77 Woods,Good,HSG D 61,845 95 Weighted Average 10,014 16.19%Pervious Area 1 51,831 83.81%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) ((Vft) (ft sec) (cfs) 8.7 60 0.0100 0.11 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.5 85 '0.0190 2.80 Shallow Concentrated Flow, Paved Kv=20.3 fps 9.2 145 Total Summary for Subcatchment 2S:PR-CULVERT. R Runoff = 6.14 cfs® 12.20 hrs, Volume= 25,116 cf, Depth= 4.34" Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Tune Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 33,000 77 Woods,Good,HSG D 2,936 98 Paved parking,HSG D 28,532 80 >75%Grass cover,Good,HSG D 4,945 98 Roofs,HSG D 69,413 81 Weighted Average 61,532 88.65%Pervious Area 7,881 11.35%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) ((/ft) (ft/sec) (cfs) .,9.6 . 100 0.1560 0.17 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.6 125 0.0500 3.60 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 4.3 390 0.0090 1.53 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 14.s 615 Total Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed—RI Type 11124-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC PaM23 Summary for Subcatchment 3S: PR-TRADERSb Runoff = 1.45 cfs Q 12.09 hrs, Volume= 4,653 cf, Depth= 4.56" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 1 10,228 80 >75%Grass cover,Good,HSG D Z023 98 Paved parking,HSG D 12,251 83 Weighted Average 10,228 83.49%Pervious Area 2,023 16.51%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.2 60 0.3300 0.46 Sheet Flow, Grass:Short -n=0.150 1`2=3.10" I2.2 60 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 4S:PR-PARK NRunoff = 2.59 cfs® 12.09 hrs, Volume= 9,178 cf, Depth= 6.03" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt—0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 16,283 98 Paved parking,HSG D 1,996 80 >75%Grass cover,Good,HSG D 18,279 96 Weighted Average 1,996 10.92%Pervious Area 16,283 89.08%Impervious Area Tc Length Slope . Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0400 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 1.0 255 0.0400 4.06 Shallow Concentrated Flow, �. Paved•Kv=20.3 fps 1.3 280 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 5S: PR-FIRST R Runoff = 4.21 cfs® 12.09 hrs, Volume= 13,649 cf, Depth= 4.78" Runoff by SCS TR-20 method,UH=',GCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr'100 yr Rainfall=6.50" Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_111 Type 11124-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 H,ydroCAD010.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Pages 24 Area(sf) CN Description 2,681 98 Roofs,HSG D 6,917 98 Paved parking,HSG D 24,696 80 >75%Grass cover,Good,HSG D 34,294 85 Weighted Average 24,696 72.01%Pervious Area 91598 27.99%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 2.4 40 0.1100 0.28 Sheet Flow, Grass:Short n=0.150 P2=3.10" 1.9 290 0.0250 2.55 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 4.3 330 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 6S:PR-EAST 1 Runoff = 1.15 cfs® 12.09 hrs, Volume-- 3,716 cf, Depth= 4.67" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 1,500 77 Woods,Good,HSG D 505 80 >75%Grass cover,Good,HSG D _ Z170 98 Paved parking,HSG D 9,555 84 Weighted Average 7,385 77.29%Pervious Area 2,170 22.71%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftjsec) (cfs) 3.5 50 0.0700 0.24 Sheet Flow, Grass:Short n=0.150 P2=MVI 1 0.3 100 0.1200 5.58 Shallow Concentrated Flow, Unpaved Kv=16.1 fps 3.8 150 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 7S: PR-1R Runoff = 3.23 cfs 11 12.09 hrs, Volume= 11,198 cf, Depth= 5.79" Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span--0.00-10.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" I Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_Rl Type III 24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 sl n 06611 02017 HydroCAD Software Solutions LLC Page 25 Area(so CN Description 1 14,215 98 Paved parking,HSG D 4,545 80 >75%Grass cover,Good,HSG D 4,440 98 Roofs,HSG D 23,200 94 Weighted Average 4,545 19.59%Pervious Area 18,655 80.41%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft). (ft/sec) (cfs) 0.5 25 0.0100 0.78 Sheet Now, Smooth surfaces n--0.011 P2=3.10" 1.1 130 0.0100 2.03 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.6 155 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 8S.. PR-1/2 BLDG 1 Runoff = 0.64 cfs® 12.09 hrs, Volume= 2,323 cf, Depth= 6.26" Runoff-by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 4,452 98 Roofs,HSG D 4,452 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 9S: PR-2R Runoff = 2.82 cfs @ 12.09 hrs, Volume= 9,884 cf, Depth— 5.91". 1 Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 16,652 98 Paved parking,HSG D 3,422 80 >75%Grass cover,Good,HSG D 20,074 95 Weighted Average 3,422 17.05%Pervious.Area '16,652 82.95%Impervious Area r . Proposed Condition Watershed Analysis-Revised June 27,2018-First Street Traders Wa P� Y J / y Proposed_R1 Type III,24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 26 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) 4cfs) 3.3 25 0.0200 0.13 Sheet Now, Grass:Short n=0.150 P2=3.10" 1.0 125 0.0100 2.03 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.3 150 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 10S: PR-3R Runoff = 2.28 cfs @ 12.09 hrs, Volume= 7,824 cf, Depth= 5.68" Runoff.by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 firs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 11,617 98 Paved parking,HSG D 4,923 80 >75%Grass cover,Good,HSG D 1 16,540 93 Weighted Average 4,923 29.76%Pervious Area 11,617 70.24%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.6 50 0.1400 0.32 'Sheet Flow, ' Grass:Short n=0.150 P2=3.10" 1A 160 0.0090. 1.93 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.0 210 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 11S: PR-BLDG 2 ' Runoff 1.27 cfs @ 12.09 hrs, Volume= 4,646 cf, Depth= 6.26" Runoff by SCS IR 20 method,UH=SCSS,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 8,905 98 Roofs,HSG D 81905 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) ((t/sw) {cfs) 6.0 Direct Entry, r ' #( sF ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way 'roposed_R1 Type Ili 24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Pam 27 Summary for Subcatchment 12S:PR4R Runoff = 3.28 cfs Q 12.10 hrs, Volume= 11,778 cf, Depth=5.91" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 5,363 98 Roofs,HSG D 14,148 98 Paved parking,HSG D 4,411 80 >75%Grass cover,Good,HSG D ' 23,922 95 Weighted Average 4,411 18.44%Pervious Area 19,511 81.56%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.3 40 0.0100 0.11 Sheet Flow, 1 Grass:Short n=0.150 P2=3.10" 0.1 20 0.0200 2.87 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.6 175 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 7.0 235 Total Summary for Subcatchment 13S: PR-BLDG 5 Runoff = 1.53 cfs® 12.09 hrs, Volume= U96 cf, Depth= 6.26" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 10,725 98 Roofs,HSG D 10,725 100.00%Impervious Area Tc Length Slope Velocity Capacity. Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 14S: GARAGES 5A&5B Runoff 0.35 cfs® 12.09 hrs, Volume= 1,263 cf, Depth= 6.26" Runoff by SCS IR 20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs ;Type III 24-hr 100 yr Rainfall=6.50" F _ Proposed Condition Watershed Analysis-.Revised June 27,2018-First Street/Traders Way Proposed R1 Type III 24-hr 100 yr Painfall=6.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Page 28 _Area(sf) CN Description ' 2,420 98 Roofs,HSG D 2AM 100.00%Impervious Area 1 Tc Length Slope Velocity Capacity Description fmin) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, ' Summary for Subcatchment 1SS: PR 5R Runoff = 3.91 cfs @ 12.09 hrs; Volume-- 13,302 cf, Depth=-5 56" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" 1 Area(sf) CN Description 2,676 98 Roofs,HSG D 1 16,431 98 Paved parking,HSG D 9,593 80 >75%Grass cover,Good,HSG D 28,700 92 Weighted Average 9,593 33.43%Pervious Area 19,107 66.57%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.0 50 0.0500 0.21 Sheet Flow, Grass:Short n=0.150 P2=3.10" 0.1 20 0.0500 4.54 Shallow Concentrated Flow, ' Paved Kv=20.3 fps 0.7 190 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 4.8 260 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 16S:PR-6R Runoff = 0.64 cfs® 12.09 hrs, Volume= 2,110 cf, Depth= 5.22"- Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.5Y' Area(sf) CN Description 2,384 98 Paved parking,HSG D 2,465 80 >75%Grass cover,Good,HSG D 4,849 89 Weighted Average 2,465 50.84%Pervious Area 2,384 49.16%Impervious Area I iProposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_RI Type III 24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC page 29 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0500 1.48 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.6 175 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.9 200 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 17S: GARAGES 6A&6B Runoff = 0.35 cfs @ 12.09 hrs, Volume= 1,263 cf, Depth 6.26" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(so (N Description 2,420 98 Roofs,HSG D 2,420 100.00%Impervious Area ' Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) {cfs) 6.0 Direct Entry, Summary for Subcatchment 18S: PR-7R ' Runoff = 1.73 cfs® 1209 hrs, Volume-- 5,932 cf, Depth= 5.68" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Tune Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(so CN Description y 8,105 98 Paved parking,HSG D 3,736 80 >75%Grass cover,Good,HSG D 700 ' 98 Roofs,HSG D 12,541 93 Weighted Average ' 3,736 29.79%Pervious Area 8,805 70.21%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) .(cfs) 29 40 0.5000 0.23 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.6 140 0.0360 3.85 Shallow Concentrated Flow, Paved Kv=20.3 fps 3.5. 180 Total, Increased to minimum Tc=6.0 min m Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed R1 Type III 24-hr'100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 19S:PR-BR Runoff = 3.59 cfs Q 12.09 hrs, Volume= 12,458 cf, Depth= 5.79" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(so CN Description 13,367 98 Paved parking,HSG D 2,287 80 >75%Grass cover,Good,HSG D 2,800 77 Woods,Good,HSG D 7,356 98 Roofs,HSG D 25,810 94 Weighted Average 5,087 19.71%Pervious Area ' 20,723 80.29%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (COS 2.9 40 0.5000 0.23 Sheet Flow, Woods:Light underbrush n=0.400 P2=3.10" 0.7 140 0.0280 .3.40 Shallow Concentrated Flow, Paved Kv=20.3 fps 3.6 180 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 20S:PR-9R ' Runoff 2.66 cfs® 12.09 hrs, Volume= 9,317 cf, Depth= 5.91" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=UO-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description t 9,402 98 Paved parking,HSG D 3,247 80 >75%Grass cover,Good,HSG D 6,273 98 Roofs,HSG D 18,922 95 Weighted Average 3,247 17.16%Pervious Area 15,675 82.84%Impervious Area ' Tc Length Slope Velocity Capacity Description Amin) (feet) (ft/ft) (ft_/sec) (cfs) 0.3 25 0.0330 1.25 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 6.7 180 0.0480 4.45 Shallow Concentrated Flow, Paved Kv=20.3 fps 1.0 205 Total, Increased to minimum Tc=6.0 min Proposed Condition Watershed Analysis Revised June 27,2018-First Street/Traders Way Proposed R1 Type 11124-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 . HydroCAD®10.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC., Page 31 Summary for Subcatchment 21S:PR-IOR Runoff = 0.80 cfs® 12.09 hrs, Volume= . 2,710 cf, Depth= 5.45." Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 244ir 100 yr Rainfall=6.50" Area,(sf) CN Description 2,830 98 Paved parking,HSG D 2,414 80 >75%Grass cover,Good,HSG D 726 98 Roofs,HSG D 5,970 91 Weighted Average 2,414 40.44%Pervious Area 3,556 59.56%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0500 1.48 Sheet Flow, Smooth surfaces n=0.011 P2=3.10" 0.6 175 0.0500 4.54 Shallow Concentrated Flow, Paved.JC:v=20.3:fps 0.9 200 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 22S: PR-11R Runoff _ 1.02 cfs @ 12.09 hrs, Volume= 3,403 cf, Depth= 5.33" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Tune Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description 3,673 98 Paved parking,HSG D 3,257 80 >75%Grass cover,Good,HSG D 726 98 Roofs,HSG D 7,656 .90 Weighted Average 3,257 42.54%Pervious Area 4,399 57.46%Impervious Area Tc Length Slope Velocity Capacity Description _(min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 25 0.0400 1.35 Sheet Flow, Smooth surfaces n=0.011 P2=3.10' 0.5 125 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.8 150 Total, Increased to minimum Tc—,6.0 min s 6 i - t Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type 11124-hr 100 yr Rainfall=6.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 02017 HydroCAD Software Solutions LLC Page 32 ' Summary for Subcatchment 23S:PR-12 Runoff = 2.53 cfs @ 12.09 hrs, Volume= U61 cf, Depth= 5.91" ' Runoff by SCS TR 20 method,UH=SCS,Weighted-CN,Time Span=0.0040.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) Cal Description ' 9,572 98 Paved.parkin&HSG D 3,245 80 >75%Grass cover,Good,HSG D 5,179 98 Roofs,HSG D ' 17,996 95 Weighted Average 3,245 18.03%Pervious Area 14,751 81.97%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftjft) (ft/sec) (cfs) 0.3 25 0.04W 1.35 Sheet Flow, ' Smooth surfaces n=0.011 P2=MY' 0.8 205 0.0500 4.54 Shallow Concentrated Flow, Paved Kv=20.3'fps 1.1 230 Total, Increased to minimum Tc=6.0 min Summary for Subcatchment 24S: PR-1/4 BLD 6 tRunoff = 0.38 cfs @ 12.09 hrs, Volume= 1,399 cf, Depth= 6.20' Runoff by SCS TR-20 method,UH=SCS,Weighted-C:N,Time Span--0.00-40.00 hrs,dt=0.05 hrs ' Type III 24-hr 100 yr Rainfall=6.50" Area(sf) .C N D.escription 2,681 98 Roofs,HSG D 2,681 100.00%Impervious Area Tc Length Slope Velocity Capacity Description t (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 25S:PR-V4 BLD 7 Runoff = 0.32 cfs @ .12.09 hrs, Volume= 1,161 cf, Depth= 6.26" Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50' r ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 100 yr Rainfall=`o.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC Page 33 Area(sf) CN Description ' 2,226 98 Roofs,HSG D 2,226 100.00%Impervious Area ' Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 26S:PR-TRADERSa Runoff = 0.27 cfs @ 12.09 hrs, Volume= 843 cf, Depth= 3.92' Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span=0.00-40.00 hrs,dt=0.05 hrs Type III 24-hr 100 yr Rainfall=6.50" Area(sf) CN Description ' 2,581 77 Woods Good HSG D 2,581 100.00%Pervious Area Tc Length Slope Velocity Capacity Description ,Orrin) (feet) (ft/ft) (ft/sec) (cfs) 2.2 60 0.3300 0.46 Sheet Flow, Grass:Short n=0.150 P2=3.10" 2.2 60 Total, Increased to minimum Tc=6.0 min ' Summary for Subcatchment 27S: PR NW 3/4 Runoff = 0.64 cfs® 12.09 hrs, Volume= Z323 cf, Depth= 6.26" ' Runoff by SCS TR-20 method,UH=SCS,Weighted-CN,Time Span--0.00-40.00 hrs,dt=0.05 hrs Type III 244tr 100 yr Rainfall=6.50" iArea(so CN Description 4,452 98 Roofs,HSG D 4,452 100.00%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) ' 6.0 Direct Entry, Summary for Pond 1P: Cultec 100HD Subsurface Structure Inflow Area_ 4,452 sf,100.00%Impervious, Inflow Depth= 6.26" for 100 yr event Inflow 0.64 cfs @ 12.09 hrs, Volume= 2,323 cf Outflow = 6.00 cfs @ 3.90 hrs, Volume= 284 cf, Atten=100%, Lag=0.0 min ,Discarded 0.00 cfs® 3.90 hrs, Volume= 284 cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 0 2017 HydroCAD Software Solutions LLC Paxy Peak Elev=116.34'@ 24.11 hrs Surf.Area=969 sf Storage=2,155 cf Plug-Flow detention time=841.7 min calculated for 283 cf(12%of inflow) Center-of-Mass det.time=486.8 min(1,230.8-744.0) Volume Invert Avail.Storage Storage Description #1A 111.46' 1,967 cf 15.50'W x 62.50'L x 5.54'H Field A 5,368 cf Overall-450 cf Embedded=4,918 cf x 40.0%Voids '. #2A 115.46' 450 cf Cultec C-100HD x 32 Inside#1 Effective Sizze=32.1"W x 12.0"H=>1.86 sf x 7.50'L=14.0 cf Overall Size=36.0"W x 12.5"H x 8.00'L with 0.50'Overlap Row Length Adjustment--+0.50'x 1.86 sf x 4 rows 2,418 cf Total Available Storage Storage Group A created with Chamber Wizard 1 Device Routing Invert Outlet Devices #1 Discarded 111.46' 0.090 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.00 cfs @ 3.90 hrs HW=111.52' (Free Discharge) -1=Exfiltration (Exfiltration Controls 0.00 cfs) Summary for Pond 2P.Cultec 330XLD Subsurface Structure Inflow Area= 45,519 sf, 81.67%Impervious, Inflow Depth= 4.27" for 100 yr event Inflow = 3.98 cfs @ 12.15 lip, Volume-- 16,196 cf Outflow = 2.33 cfs @ 12.41 hrs, Volume= 12,054 cf, Atten=41%, Lag=15.3 min Discarded= 0.00 cfs @ 5.75 hrs, Volume= 586 cf 1 Primary = 2.33 cfs @ 12.41 hrs, Volume= 11,468 cf Routing by Dyn-Stor Ind method,Time Span 0.00-40.00 hrs,dt-0.05 hrs/3 Peak Mev=108.56'@ 12.41 hrs Surf.Area=2,102 sf Storage=5,717 cf Plug-Flow detention time=184.6 min calculated for 12,054 cf(74%of inflow) Center-of-Mass det.time=92.9 min(914.1-821.2) ' Volume Invert Avail.Storage Storage Description #1A 103.21' 4,722 cf 35.331W x 59.5011.x 7.041H Field A 14,804 cf Overall-2,999 cf Embedded=11,805 cf x 40.0%Voids #2A 107.21' 2,999 cf Cultec R-330XL x 56 Inside#1 ' Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50'L with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows 7,721 cf Total Available Storage . Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 103.21' 0.090 in/hr Exfiltration over.Surface area #2 Primary 107.75' 8.0" Round Culvert X 2.00 L-54.0' CPP,square edge headwall, Ise=0.500 S ' Proposed Condition Watershed Analysis-Revised June 27,2018-First Street Traders Way Y Proposed_R1 Type 11124-hr 100 yr Rainfall=6.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611'0 2017 HydroCAD Software Solutions LLC Page 35 Inlet/Outlet Invert-107.75'/107.00' S=0.0139'/' Cc=0.900 n=0.010, Flow Area--0.35 sf Discarded Outflow Max4.00 cfs @ 5.75 hrs HW=103.28' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow Max=2.32 cfs @ 12.41 hrs HW=108.56' TW=0.00' (Dynamic Tailwater) L2=Culvert (Inlet Controls 232 cfs @ 333 fps) Summary for Pond 3P:Cultec 330XLD Subsurface Structure Inflow Area= 28,979 sf, 88.19%Impervious, Inflow Depth= 6.02" for 100 yr event Inflow 4.09 cfs @ 12.09 hrs, Volume-- 14,530 cf Outflow = 2.38 cfs @ 12.21 hrs, Volume-- 8,986 cf, Atten=42%, Lag=7.4 min Discarded= 0.01 cfs @ 3.35 hrs, Volume= 615 cf Primary = 2.37 cfs @ 12.21 hrs, Volume-- 8,372 cf Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=109.16'@ 12.21 hrs Surf.Area=2,102 sf Storage=6,960 cf Plug-Flow detention time=243.0 min calculated for 8,986 cf(62%of inflow) Center-of-Mass det.time=137.2 min(893.3-756:0) Volume Invert Avail Storage Storage Description #1A 102.96' 4,722 cf 35.33'W�x 59.50'L x 7.041H Field A 14,804 cf Overall-Z999 cf Embedded-11,805 cf x 40.0%Voids #2A 106.96' Z999 cf Cultec R-330XLHD x 56 Inside#1 Effective Size=47.8"W x 30.0'H=>7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment-+1.50'x 7.45 sf x 7 rows 7,721 cf Total Available Storage` Storage Group A created with Chamber Wizard Device Routing Inverf .Outlet Devices #1 Discarded 102.96' 0.090 in/hr Exfiltration over Surface area #2 Primary 108.33' 8.0" Round Culvert X 2.00 L=38.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=-108.33'/107.95' S=0.0100'/' Cc=0.900 n=0.010, Flow Area--0.35 sf Discarded Outflow Max--0.00 cfs Cam?3.35 hrs HW=103.03' (Free Discharge) L1=Exfiltration (E atration Controls 0.00 cfs) Primary Outflow Max=235 cfs @12.21 hrs HW=109.15' TW=108.10' (Dynamic Tailwater) L2=Culvert (Inlet Controls 2.35 cfs @ 337 fps) i 1 \ Proposed Condition Watershed Analysis-Revised June27,2018-First Street/Traders Way Proposed_R1 Type III24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD@ 10.00-20 sJn 06611 02017 HydroCAD Software Solutions LLC Page_36 Summary for Pond 4P: Cultec 330XLD Subsurface Structure Inflow Area= 34,647 sf, 87.27%Impervious, Inflow Depth= 6.02" for 100 r event pe P Y Inflow = 4.80 cfs @ 12.01 hrs, Volume= 17,375 cf 1 Outflow = 3.31 cfs @ 12.19 hrs, Volume= 12,043 cf, Atten=31%, Lag=5.8 min Discarded = 0.00 cfs @ 3.15 hrs, Volume-- 616 cf Primary = 3.30 cfs @ 12.19 hrs, Volume-- 11,427 cf 1 Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs,/3 Peak Elev=103.30'@ 12.19 hrs Surf.Area=2,102 sf Storage=7,298 cf Plug-Flow detention time=208A min calculated for 12,028 cf(69%of inflow) Center-of-Mass det.time=115.0 min(871.6-756.6) Volume Invert Avail.Storage Storage Description #lA 96.76' 4,722 cf 35.331W x 59.5011.x 7.04'11 Field A 14,804 cf Overall-2,999 cf Embedded=11,805 cf x 40.0%Voids #2A 100.76' 2,999 cf Cultec R-330XLHD x 56 Inside#1 I Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00%=52.2 cf Overall Size=52.0'W x 30.5"H x 8.50'L with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 7 rows 7,721 cf Total Available Storage Storage Group A created with Chamber Wizard Device_ Routing Invert Outlet Devices #1 Discarded 96.76' 0.090 in/hr Exfiltration over Surface area #2 Primary 102.W 8.0" Round Culvert X 2.00 L=34.0' CPP,square edge headwall, Ke=0500 Inlet/Outlet Invert=102.00'/101.66' S=0.0100'/' Cc=0.900 n=0.010, Flow Area=0.35 sf Discarded Outflow Max=0.00 cfs @ 3.15 hrs HW=96.83' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow Max=3.28 cfs @ 12.19 hrs HW=103.29' TW=0.00' (Dynamic Tailwater) t--2=Culvert (Inlet Controls 3.28 cfs @ 4.70 fps) Summary for Pond 5P: Cultec 330XLD Subsurface Structure �. az3' Inflow Area= 31,120 sf, 69.17%Impervious, Inflow Depth= 5.62" for 100 yr event Inflow 4.26 cfs 0 12.09 hrs, Volume= 14,564 cf Outflow = 1.73 cfs @ 12.31 hrs, Volume= 8,320 cf, Atten=59%, Lag=13.4 min 1 Discarded= 0.00 cfs @ 4.95 hrs, Volume= 642 cf Primary = 1.73 cfs @ 12.31 hrs, Volume= 7,678 cf _ Routing by Dyn-Stor-Ind method,Time Span-7 0.00-40.00 hrs,dt=0.05 hrs/3 Peak Mev=109.21'@ 12.31 hrs Sur£Area=2,260 sf Storage=7,521 cf Plug-Flow detention time=257.4 min calculated for 8,309 cf(57%of inflow) Center-of-Mass det.time=150S min(922.7-772.1) i i Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III 24-hr 100 yr Rainfall=6.50" I Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 sJn 06611 ®2017 HydroCAD Software Solutions LLC Page 37 Volume Invert Avail.Storage Storage Description #1A 102.96' 5,097 cf 20.83'W x 108.50'L x 7.04'H Field A 15,917 cf Overall-3,174 cf Embedded-=12,743 cf.x 40.0%Voids #2A 106.96' 3,174 cf Cultec R-330XLHD. x 60 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50'L with 1.50'Overlap Row Lena Adjustment=+1.50'x 7.45 sf x 4 rows 8,271 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 102.96' 0.090 irVhr Exfiltration over Surface area #2 Primary 108.59 12.0" Round Culvert L=8.0' CPP,square edge headwall, Ke=.0.500 Inlet/Outlet Invert=108.50'/108.25' S=0.0313'/' Cc=0.900 n=0.010, Flow Area--0.79 sf Discarded Outflow Max=0.00 cfs @ 4.95 his HW=103.03' (Free Discharge) L1=Exfiltration (Exfjltration Controls 0.00 cfs) Primary OutFow Max=1.71 cfs @ 12.31 his HW=109.21' TW=0.00' (Dynamic Tailwater) L2=Culvert (Inlet Controls 1.71 cfs @ 2.87 fps) Summary for Pond 6P.Cultec 330XLD Subsurface Structure Inflow Area= 20,931 sf, 70.62%Impervious, Inflow Depth= 5.68" for 100 yr event Inflow 2.88 cfs® 12.09 his, Volume-- 9,905 cf Outflow = 0.22 cfs ll 13.13 hrs, Volume= 3,842 cf, Atten=92%, Lag=62.5 min Discarded= 0.00 cfs @ 5.00 his, Volume= 539 cf Primary = 0.22 cfs® 13.13 hrs, Volume= 3,3M cf Routing by Dyn-Stor-Ind method,Time Span--0.00-40.00 his,dt=0.05 his/3 Peak Elev=114.11'®13.13 hrs Surf.Area=1,886 sf Storage=6,618 cf Plug-Flow detention time=386.7 min calculated for 3,842 cf(39%of inflow) Center-of-Mass det.time=245.2 min(1,014.7-769.5) Volume Invert Avad.Storage Storage Description #1A 107.46' 4,248 cf 25.67'W x 73.501L-x 7.041H Field A i 13,284 cf Overall-2,664 cf Embedded=10,620 cf x 40.0%Voids #2A 111.46' 2,664 cf Cultec R-330XLHD x 50 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.50'Overlap Row Length Adjustment-+1.50'x 7.45 sf x 5 rows 6,912 cf Total Available Storage Storage Group A created with Chamber Wizard Proposed Condition Watershed Analysis-Revised June 27 2018-First Street Traders 1� Y 1 / Way Proposed_R1 Type 111 24-hr 100 yr RainfalI=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 ©2017 HydroCAD Software Solutions LLC . Page 38 Device Routing Invert Outlet Devices #1 Discarded 107.46' 0.090 in/hr Exfiltration over Surface.area #2 Primary 113.67 4.0" Round Culvert L=18.0' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=113.67'/113.00' S=0.0372'/' Cc=0.900 n=0.010, Flow Area--0.09 sf Discarded Outflow Max--0.00 cfs @ 5.00 hrs HW=107.53' (Free Discharge) t-1=Exfiltration (Fxfiltration Controls 0.00 cfs) Primary OutFow Max=0.22 cfs @ 13.13 hrs HW=114.11' TW=0.0V (Dynamic Tailwater) t-2=Culvert (Inlet Controls 0.22 cfs @ 2.53 fps) Summary,for Pond 7P.Cultec 330XLD Subsurface Structure Inflow Area= 30,501 sf, 70.60%Impervious, Inflow Depth= 5.65" for 100 yr event ' Inflow = 4.18 cfs @ 12.09 hrs, Volume= 14,373 cf Outflow = 2.02 cfs @ 12.25 hrs, Volume= 9,595 cf, Atten=52%, Lag=9.9 min Discarded = 0.01 cfs @ 4.95 hrs, Volume= 769 cf Primary = 2.02 cfs @ 12.25 hrs, Volume= 8,826 cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Peak Mev=114.29'@ 12.25 hrs Surf.Area=2,707 sf Storage=6,784 cf Plug:Flow detention time=234.6 min calculated for 9,595 cf(67%of inflow) Center-of-Mass deL time=137.5 min(907.5-770.1) Volume Invert Avail.Storage Storage Description #1A 109.21' 6,070 cf 59.50'W x 45.50%x 7.04111 Field A 19,064 cf Overall-3,889 cf Embedded=15,174 cf x 40.0%Voids #2A 113.21' 3,889 cf Cultec R-330XLHD x 72 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.00'L=52.2 cf Overall Size=52.0"W x 30.5"H x 8.501 with 1.5V Overlap Row Length Adjustment-+1.50'x 7.45 sf x 12 rows 9,959 cf Total Available Storage Storage Group A created with Chamber Wizard' Device Routing Invert Outlet Devices #1 Discarded 109.21' 0.090 in/hr Exfiltration over Surface area #2 Primary 113.59 12.0" Round Culvert L=56.0. CPP,square edge headwall, Ke=0.5M Inlet/Outlet Invert=113-V/113.00' S=0.0089'/' Cc=0.900 n=0.010, Flow Area--0.79 sf 'Y Discarded OutFow Max=0.01 cfs @ 4.95 hrs HW=109.28' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.01 cfs) Primary Outflow Max--2.02 cfs @ 12.25 hrs HW=114.29' TW=0.00' (Dynamic Tailwater) t--,?=Culvert (Inlet Controls 2.02 cfs @ 3.03 fps) i Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type ifl 24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 Hydro.CAD010.00-20 s/n 06611 ©2017 H.ydroCAD Software Solutions LLC Pag39 Summary for Pond 8P: Existing BVW Inflow Area= 173MO sf, 5C24%Impervious, Inflow Depth= 5.27" for 100 yr event Inflow = 18.58 cfs @ 12.12 hrs, Volume= 76,082 cf Outflow = 18.13 cfs @ 12.15 hrs, Volume= 76,082 cf, Atten=2%, Lag=1.8 min Discarded= 0.00 cfs @ 12.15'hrs, Volume= 13 cf Primary = 18.12 cfs @ 12.15 hrs, Volume= 76,068 cf Routing by Dyn-Stor-Ind method,Time Span=0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=110.06'@ 12.15 hrs Surf.Area=1,908 sf Storage=990 cf Plug-Flow detention time=0.4 min calculated for 75,987 cf(100%of inflow) Center-of-Mass det.time=0.4 min(782.0-781.6) Volume Invert Avail.Storage Storage Description #1 108.45 2,278 cf Custom Stage Data(Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 108.45 0 0 0 . 109.00 100 27 27 110.00 1,600 850 877 110.50 4,000 1,400 2,278 Device Routing Invert Outlet Devices #1 Primary 108.45' 30.0" Round Culvert L=118.0' RCP,groove end projecting, Ke=0.200 Inlet/Outlet-Invert=108.45'/94.00' S=0.1225'/' Cc=0.900 n=0.011, Flow Area--4.91 sf #2 Discarded 108.45' 0.090 irOu Exfiltration over Surface area Discarded Outflow Max=0.00 cfs @ 12.15 hrs HW=110.06' (Free.Discharge) t-2=Exfiltration (Exfiltration Controls 0.00 cfs) Primary Outflow Max=18.08 cfs @ 12.15 hrs HW=110.06'.-TW=0.00' (Dynamic Tailwater) t-1=Culvert (Inlet Controls 18.08 cfs @ 5.40 fps) Summary for Pond 9P:Cultec 330XLD Subsurface Structure Inflow Area= 25,810 sf, 80.29%Impervious, Inflow Depth= 5.79" for 100 yr event Inflow = 3.59 cfs @ 12.09 hrs, Volume= 12,458 cf Outflow = 0.16 efs @ 14.76 hrs;Volume= 3,433 cf, Atten=96%, Lag=160.5 min Discarded = 0.01 cfs @ 4.90 hrs, Volume= 738 cf Primary = 0.15 cfs @ 14.76 hrs, Volume= 2,694 cf tRouting by Dyn-Stor-Ind method,Time Span=0.W-40.00 hrs,dt=0.05 hrs/3 Peak Elev=119.47 @ 14.76 hrs Surf.Area=2,616 sf Storage=9,592 cf Plug-Flow detention time=520.2 min calculated for 3,433 cf(28%of inflow) Center-of-Mass det.time=339.4 min(1,105.9-766A) j '{fit l :YI 95 Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_RI Type II124-hr 100 yr Rainfall=6.50" ' Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD010.00-20 s/n 06611 ®2017 HydroCAD Software Solutions LLC Page 40 Volume Invert Avail.Storage Storage Description #1A 112.46' 5,864 cf 49.83'W x 52.50'L x 7.04'H Field A 18A23 cf Overall-3,763 cf Embedded=14,660 cf x 40.0%Voids #2A 116.46' 3,763 cf Cultec R-330XLHD x 70 Inside#1 Effective Size=47.8"W x 30.0"H=>7.45 sf x 7.001=52.2 cf Overall Size=52.0"W x 30.5"H x 8.50%with 1.50'Overlap Row Length Adjustment--+1.50'x 7.45 sf x 10 rows 9,627 cf Total Available Storage 1 Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 112.46' 0.090 in/hr Exfiltration over Surface area #2 Primary 119.17 4.0" Round Culvert L=32.5' CPP,square edge headwall, Ke=0.500 Inlet/Outlet Invert=119.17/118.84' S=0.0102'/' Cc=0.900 n=0.010, Flow Area--0.09 sf Discarded Outflow Max=0.01 cfs @ 4.90 hrs HW=112.53' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.01 cfs) Primary Outflow Max--0.15 cfs @ 14.76 hrs HW=119.47 TW=0.00' (Dynamic Tailwater) t-2=Culvert (Inlet Controls 0.15 cfs @ 1.86 fps) Summary for Pond 28P:Cultec 100HD Subsurface Structure Inflow Area= 4,452 sf,100.00%Impervious, Inflow Depth= 6.26" for 100 yr event Inflow = 0.64 cfs® 12.09 hrs, Volume= 2,323 cf Outflow = 0.00 cfs @ 5.15 hrs, Volume= 428 cf, Atten=100%, Lag=0.0 min Discarded= 0.00 cfs @ 5.15 hrs, Volume= 428 cf Routing by DynStor-Ind method,Time Span--0.00-40.00 hrs,dt=0.05 hrs/3 Peak Elev=113.98'@ 24.08 hrs Surf.Area=1,470 sf Storage=2,070 cf tPlug-Flow detention time=778.1 min calculated for 428 cf(18%,of inflow) Center-of--Mass det.time=492.6 min(1,236.6-744.0) Volume Invert Avail.Storage Storage Description #1A 110.46' 2,989 cf 12.00'W x 1225014 x 5.54'H Field A 8,146 cf Overall-673 cf Embedded=7,473 cf x 40.0%Voids #2A 114.46' 673 cf Cultec C 10OHD x 48 Inside#1 Effective Size=32.1"W x 12.0"H=>1.86 sf x 7.50'L=14.0 cf Overall Size=36.0"W x 12.5"H x 8.001 with 0.50'Overlap Row Length Adjustment=+0.50'x 1.86 sf x 3 rows 3,662 cf Total Available Storage Storage Group A created with Chamber Wizard 1 Device Routing Invert Outlet Devices #1 Discarded 110.46' 0.090 in/hr Exfiltration over Surface area it i 5i� sE v Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_RI Type III 24-hr 100 yr Rainfall=6.50" Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD910.00-20 s/n 06611 ®2017 HydroCAD Software Solutions.LLC Page 41 Discarded Out Flow h1ax=0.00 cfs @ 5.15 hrs HW=110.52' (Free Discharge) L1=Exfiltration (Miltration Controls 0.00 cfs) Summary for Link 1L:Runoff towards Traders Way drainage system Inflow Area= 14,832 sf, 13.64%Impervious, Inflow Depth= 4.45" for 100 event ,83 pervi P Yl' Inflow 1.71 cfs @ 12.09 hrs, Volume-- 5,496 cf 1 Primary = 1.71 cfs @ 12.09 hrs, Volume= 5,496 cf, Atten=0%, Lag=0.0 min Primary outflow-Inflow,Time Span--0.00-40.00 hrs,dt=0.05 hrs Summary for Link 2L: Runoff via existing 30"RCP Culvert Inflow Area= 173,380 sf, 54.24%Impervious, Inflow Depth= 5.26" for 100 yr event Inflow _ 18.12 cfs @ 12.15 hrs, Volume= 76,068 cf Primary 18.12 cfs @ 12.15 hrs, Volume-- 76,068 cf, Atten=0%, Lag=0.0 min ' Primary outflow=Inflow,Time Span--0.00-40.00 hrs,dt=0.05 hrs Summary for Link 3L: Flow towards First Street Inflow Area= 84,720 sf, 61.00%Impervious, Inflow Depth= 3.92" for 100 yr event Inflow 4.91 cfs @ 12.09 hrs, Volume= 27,678 cf Primary 4.91 cfs @ 12.09 hrs, Volume= 27,678 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs Summary for Link 4L:Flow to City of Salem Conservation Land Inflow Area= 415,941 sf, 61.68%Impervious, Inflow Depth= 4.13" for 100 yr event Inflow = 28.66 cfs @ 12.16 hrs, Volume= 143,171 cf Primary = 28.66 cfs @ 12.16 hrs, Volume= 143,171 cf, Atten=0%, Lag=0.0 min Primary outflow-Inflow,Time Span--0.00-40.00 hrs;dt=0.05 hrs Summary for Link 5L:Flow to the east Inflow Area- 27AM sf, 66.30%Impervious, Inflow Depth= 5.56" for 100 yr event Inflow 3.74 cfs @ 12.09 hrs, Volume= 12,894 cf Primary = 3.74 cfs @ -12.09 hrs, Volume= 12,894 cf, Atten=0%, La.-0.0 min Primary outflow Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs S Proposed Condition Watershed Analysis-Revised June 27,2018-First Street/Traders Way Proposed_R1 Type III24-hr 100 yr Rainfa11=6.y0" 1 Prepared by Williams&Sparages Printed 7/1/2018 HydroCAD®10.00-20 s/n 06611 m 2017 HydroCAD Software Solutions LLC Page 42 Summary for Link Q:Total flow from within limit of watershed analysis Inflow Area— 443,775 sf, 61.97%Impervious, Inflow Depth= 4.22" for 100 yr event Inflow = 31.58 cfs @ 12.14 hrs, Volume-- 156,065 cf Primary = 31.58 cfs @ 12.14 hrs, Volume= 156,065 cf, Atten=0%, Lag=0.0 min i Primary outflow=Inflow,Time Span=0.00-40.00 hrs,dt=0.05 hrs Summary for Link 7L:Proposed Drain Line Inflow Area=' 108,362 sf, 72.50%Impervious, Inflow Depth= 2.49" for 100 yr event Inflow = 3.70 cfs @ 12.29 hrs, Volume= 22,502 cf . Primary = 3.70 cfs @ 12.29 hrs, Volume= 22,502 cf, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span--0.00-40.00 hrs,dt=0.05 hrs 1 1 1 1 1 1 � 1 1 Stormwater Report Compliance Calculations 40 First Street &45 Traders Way, Salem, Massachusetts February 28,2018 i Revised June 27, 2018 1.0 Standard 1-No Untreated Discharges or Erosion to Wetlands: • Untreated Discharges: ` To document compliance that new discharges are adequately treated refer to calculations for Standards 4 through 6. 2.0 Standard 2-Peak Rate Attenuation: • Refer to Total Peak Rate of Runoff Comparison Table below(see'Mitigative Drainage Study) Total Peak Rate of Runoff Comparison Location(Total Flow from within limit of analysis) Link 6L 2-Year 10-Year 100-Year ' 24 Hour 24 Hour 24 Hour Description Type III Type III Type III Storm Event Storm Event Storm Event Existing Peak ! Rate of Runoff(Cfs) 12.6 23.1 39.0 Proposed Peak Rate of Runoff 11.3 17.9 31.6 (cfs) Decrease -1.3 -5.2 -7.4 r3.0 Standard 3-Stormwater Recharee: • Recharge Volume: R,,required=F x Impervious Area Site consists of Hydrologic Soils Group D: Fc=0.10in. Pro_ posed Impervious Area on site: A=215,775 ft2(Roof=80,785 ft2;Driveway&walks=134,990 ft2) R„required=(215,775 ft2)x(0.10 inch)/12 inch/ft=1,798 ft3 Total R,,provided=48,591 ft3-below the lowest outlet,Therefore,meets the standard ' (Provided u1 subsurface stormwater management areas.) -Page 2-1 Stormwater Report Compliance Calculations 40 First Street&45 Trader's Way,Salem, MA February 28, 2018 Revised:June 27, 2018 . • Capture Area Adjustment: Total Proposed impervious area:215,775 ft2 Site impervious area draining to recharge facility:157,879 ft2(see Miti alive Drainage Stud g g Y) Ratio of total site impervious area to site impervious area draining to recharge facility= (215,775)/ (157,879) =1.37 Adjusted minimum required recharge volume=(1,798) (1.37) =.2,457 ft3 Total R„provided=48,591 ft3 Therefore,meets the standard rDrawdown Within 72 Hours: Tdrawdown=R,,/ (K)(Bottom Area) ' Rv Pond 1P=4,452 ft2 x 0.1 inch/12 inch/ft=37.1 ft3 K=0.09 in/hr(Rawls Rate for"D"soils) Bottom Area=969 ft2(see Mitigative Drainage Study) Tdrawdown=37.2/ [(0.09)(969)/12] =5.1 hours<72 hours;Okay R,Pond 2P=11,617 ft2x 0.1 inch/12 inch/ft=96.8 ft3 K=0.09 in/hr(Rawls Rate) Bottom Area=2,102 ft2(see Mitigative Drainage Study) Tdrawdown= 96.8/ [(0.09)(2,102)/12] =6.1 hours<72 hours;Okay ' R„Pond 3P=25,557 hex 0.1 inch/12 inch/ft=213.0 ft3 K=0.09 in/hr(Rawls Rate) Bottom Area=2,102 ft2(see Mitigative Drainage Study) Tdrawdown= 213.0/ [(0.09)(2,102)/12] =13.5 hours<72 hours;Okay ' R,Pond 4P=30,236 rt2 x 0.1 inch/12 inch/ft=252.0 ft3 K=0.09 in/hr(Rawls Rate) Bottom Area=2,102 ft2(see Mitigative Drainage Study) Tdrawdown= 252.0/ [(0.09)(2,102)/12] =16.0 hours<72 hours;Okay R„Pond 5P=21,527 ft2 x 0.1 inch/12 inch/ft=179.4 ft3 K=0.09 in/hr(Rawls Rate) Bottom Area=2,260 ft2(see Mitigative Drainage Study) Tdrawdown= 179.4/ [(0.09)42,260)/12] =10.6 hours<72 hours;Okay 1 Page 2-2 f� 3� Stormwater Report Compliance Calculations 40 First Street&45 Trader's Way, Salem, MA February 28, 2018 Revised:June 27, 2018 R„Pond 6P=14,781 ft2x 0.1 inch/12 inch/ft=123.2 ft3 K=0.09 in/hr(Rawls Rate) Bottom Area=1,887 ft2(see Mitigative Drainage Study) Tdrawdown= 123.2/ 0.09 1,887 12 =8.7 hours<72 hours;Oka R,,Pond 7P=24,534 ft2 x 0.1 inch/12 inch/ft=179.5 ft3 K=0.09 in/hr(Rawls Rate) Bottom Area=2,707 ft2(see Mitigative Drainage Study) Tdrawdown= 179.5/ [(0.09)(2,707)/12] =8.8 hours<72 hours;Okay R„Pond 8P=Not Applicable(Existing Wetlands being modeled as a pond w/30" outlet) R,Pond 9P=20,723 ft2x 0.1 inch/12 inch/ft=172.7 ft3 ' K=0.09 in/hr(Rawls Rate) Bottom Area=2,616 ft2(see Mitigative Drainage Study) Tdrawdown= 172.7/ [(0.09)(2,616)/12] =8.8 hours<72 hours;Okay It,Pond 28P=4,452 ft2x 0.1 inch/12 inch/ft=37.1 ft3 K=0.09 in/hr(Rawls Rate) ' Bottom Area=1,470 ft2(see Mitigative Drainage Study) Tdrawdown= 37.1/ [(0.09)(1,470)/12] =3.4 hours <72 hours;Okay 4.0 Standard 4-Water Quality: ' O Water Quality: VWQ required=(DwQ)(Ai-P) DwQ=0.50 in. Aimp=215,775 ft2 VWQ required= [(0.5)(215,775)]/12=8,990 ft3 VWQ provided=48,591 ft3(provided below lowest hydraulic outlet device) o TSS Removal: See TSS removal calculation worksheets below. Pretreatment Chain=44% Subsurface Infiltration Pond=80% 11 ' Page-2-3 a• 4' $ i. Stormwater Report Compliance Calculations 40 First Street&45 Trader's Way,Salem, MA February 28.,2018 Revised:June 27, 2018 5.0.Standard 5-Land Uses With Higher PotentialPollutant Loading:nk: ' This project is not being considered as a LUHPPL. 6.0 Standard 6-Critical Areas: The stormwater discharge from this property is not within an Interim Wellhead Protection Area of a public water supply nor within a Zone II. 7.0 Standard 7-Redevelopment: This project is not being considered as a redevelopment. 8.0 Standard 8-Construction Period Controls: A Stormwater Pollution Prevention Plan SWPPP provided. � )will be 9.0 Standard 9-Long Term Operation and Maintenance Plan: i See Section 5.0 Long Term Operation and Maintenance Plan 10.0 Standard 10-Illicit DischargLes to Drainage System: There are no proposed illicit discharges into the Stormwater Management Systems to be constructed as shown on the site plan. l i Page 2-4 I i cncn � � � � wa o0 „ ^ 0a8 'd - z o � IN - a g z00 � coZ in - • T - . 102E Cl'� _ ° � � � ® CHATFIELD-HOLLIS-ROCK OUTC OP v^ COMPLEX, 15-35% SLOPES 25• WIDE 0 HSG D RIP L �p P p PLAN BOOK SLOPE I35MPLAN 53 Q�`,QS EX-CB ,32 _ 2.5'W CONC. - 73A ° 64,779 S.F. 1 S �°s RET SGC WHITMAN FINE SANDY LOAM, 0-3/o CN=94 cA N 1 I 1c=9.2 min ?� SLOPES, EXTREMELY STONY �. � \ I HSG: D 1� b , I 133 DMH 9 PACES *` N PAYEil1£NT PAVED OVER h �i � r 1 O PRlNKLER, 1 / I �I ^ PAVEMENT 4 IEXI pNG J£RSF?' / G I•EX. DMH BIERS t111 RIM--119.87 TC i , 5.27 PAVEMENT 1 134 D ➢ 9 PACES ` 136"RCP INV O T 36"RCP INV IN= 115..17 area EX. CB ` / RIM=J32.85 136 p OWN R M 132.84 a 12'RCP INV=129.25 PAVEMENT c+ EX CB 12'RCP INV-129.24 •, A 4 R1M=132.99 \ 12'RCP INV IN 128.39 PAVEMENT c"\ _ J. J f 14 iEX �.5-T EX. DBLGRATE 12'RCP OUr 128.19 r� I I \ CB R/M13r,71 H �QSNIENT /> / ~ - / A �' ➢ -� ,6 9 S. \ 12'RCP INV IN=127.71 R � & ACCE$S + o ��� C � """" I PAVEMENT i- \ / 12"RCP INV our .8 R 0 WIDE TURPIAROU lL 26 PAGE 21 b PAVEMENT �, ry \ t'•!1r ,s,. u,�� � 'r ... &0• SEl; BOOK o '� EX. CB � i�' � � 1 _ RIM=131.84 / A 77 ca str ACM Rvt FFitc£ PAVEiNE PAVEMENT 10'PVC INV IN=12584 ! J 3 1.66 15' RCP INV OUT=125.64 EP� ` �w� '36 "p 1 , r 12 RCP =123.66 v� dw ` r �.. .� -- Pp t�2 15" !NV 1N=122.66 � .f5" RCP DRAIN r J _ �'' ` � j� '' l ! /' ➢ -.. \o !P , OUT=120.06 - - - r _of_------(1w f� �_ / ` I b _ :- TC I 3 t 32 ram"'- A-I3 8, F r" '�' -y 1 j l�` A-12 LINE OF 60ULD£RS 3'X X3'N i 11 ``� I ➢ _!4 J 1 I 1 b I c I - EX DMH \taor ♦ �8 � � D �• �-T "1 - \ �� ` PAVEMENT RIM-130.57 ➢ A .� - ! 5174UCTURE DAMAGED ` 130. A-6. 10 A-9 A-8 �._A-7 `� \ \ \ ` \ `+� / �1 ! f "^ / j I 0 2 lNVS=NA "RCP INV O(/T 2 .97 A-15 \ �' P / \ �� \ ��3Tr t -P RK ` I + ` ` j I +� M w c y, ENV'�1fi 6RCP 1 �;?o\ \ �3a} ' 18,653 ' +I ? r / / ` / I o w aa; w o A-6\ , N r �'s\w p; \ � CN=96 4S 1 f j \ \ r �\ l 5L o a u RM-1 .44 130 �1e ,,e - \ ; 1 1 \ ,� \ c=6.D min y ! ` I J H uQ w� 402 fs' RCP INV=123.79 "'a N \ "� \A-16 ` f \ \ -- k �1 \ '�� l \ ` I Va) 0�1 N C�J 4'o J \ �p ECGE OF BORDE INC , 1 pp Tc J '(7 IL VEGETATED It IDS ro \ \E 1 9.I I HO j \ 4 r I I.LJ -"1 y a) Q vs vs N o \ A-/7 I \ 1 T ��i w � 01 cn E` J v I 'C >► Z u- IV EX. DMH \ \ \ A-18 f� } v" m __ 142- / / 1 \ r F q I C .�T� {-' ❑ ❑ ❑ lA1=124.69 O V "R INV IN 115.49 �� \ \ \• ,1 �` `� ' �. I PAVEMENT - 9 � L'L' = 6 3 P INV OU 015.49 J l/ •a1 i •Q n t� D \ �\ / 1 \ �' tEDG6 f l �� ❑ ❑ w G. ❑ ® LJ a-19 A�3 \ \ \ I l f t Q cc A \ \ I ( A 20 b \ \ \\ t / / l l l !� / / ®e g EX DAIH 4 39 I O cc: a r 36"RCP !NV IN109,64 Y =36"RCP INV OU 106.19 \ \ sBDH-F 99 S. \ \ t�6ry �ry / g® g ® ._- lc= .5tA 'n\N� A-1 / 24`RCP IN 10,5 b \ \ \� PAVEMENT I� ! �\ s.AS RC Dl. DMH , -22 A-33 � / ( � EX, CB RIM=117.05 , [p RIM- \ 36"RCP INV IN= 9.75 , t ` \ 2S ' , ` '� ` \ \\ 15" RCP INV 1 f2.15 ` 24" RCP INV IN- 0.55 \ J i6 ` s - 15"RCP INV IN- RCP 36" INV OUT .A. °' o, 32 \ ' TOP F DRf L N £ 102E VJA7L�R LEVEL ® 1 .35 \\\ CHATFIELD-HOLLIS-ROCK OUTCROP _ . \ A 23 COMPLEX, 15-35% SLOPES 114 \ HSG D �_ ,� 602 I o URBAN LAND 1 (, 126-- rdP DR!L HOLD m°J G: OT RATED; ASSUMED I CC v ELEV. r 15. 1 +O - ` ` 1 A EX--FIRST w p \ \ 6 \ 2 l ( 0 161,289 S.F. O-25 a ,m .c 1 ,.- �\ 102E \ bf CN=77 n I , fro �} o \ \ \ / �C Tc=12.6 min I to GHATME�D41,9LLI -�OCKbU CR� / o } \ --- �-26 FE lNJ�1o4s \ OMPLE)X,�35/o SLOO�E �� ® I Q L 1 '�� -/ / /\ \ -2 TOE & CEME --- HSG D� o DERS F.AD LL\j.5'W 5S I C) r .r l ' rvo CIV= Q L,J 1 v 1 a Tc i \ / • / f ® 1 I lb PAVEMENT - - � J �'',� 1 Lu .• 1�VZD ' 1f "F \� � i!� \ �1® � + l0 Iff � M N I EX. CB AIM°Q9.14 ` 00 O l(7-. w LEGEND OF SYMBOLS 1 MY106.95 ,� `� \ --1 ( �\ _108 ` i5' RCP INV 103.10 T 30 INV IN-94� �_ \ 1 I C �_ 6"INV OUT 93.74 \ / / t r- \ �.N' C6NER EXISTING WATERSHED BOUNDARY SSDH-F \ '� ~�- \ -I ` R/M=f06.72 EX. DMH 00 RJM=106.73 L a D EX. DMH �Q ` \ `� -� ^ >•ps 36"RCP INV IN=101.07 .• -(�'P INV 102.83 z u.J Q r 0o RIM=107.21 -1 3 APPROX. CB EX. CB 6'RCP INV OUT-92.92 `�` ---_ FROM RECORD PlAW.9-- -EX. 104.93 O ,ao . fX sa 0L73 EXISTING SOIL BOUNDARY RIM 102 _ w d40x I� ..+ ?1 f02.61 2 v �k ao EX, DMH 000c V vGC VG �� -� C !T ^ N - -_ ._ RIM=J09.94 -'' n� EX D \ \ ,,oem / W J = TIME OF CONCENTRATION FLOW PATH ➢ ➢ ➢ 36"RCP, 101.64 cS FIRST STREET p ¢ u er RIM=1 DYL •t,nsx 36"RCP 1 10 1.74 . 11"R IN v DYL Y DYL toass u � n tp DYL 1 ® m.7a •to» 1 N IN=96.Of 0 Q o MANHOLE107.75 DMH covER (PUBLIC-50 WIDE) Z 36' OUr95.0� M=107:75 L 10 O � N SUBCATCHMENT DESIGNATION S /Av.s= LL OF WATER \ / sED� vcc vcC IT V PAVED WALK EU _ - _ 0 _ r 108 - N •+oi© `DH_F -llNE OF BQ(JLDEBS 3 L ����� - �- -_ 10--}p4- ce UNE OF BOULDERS 3Hw 0 �� j M,M 704.72 O 1'W CONC. HEADWALL 1 �P � 36' RCP INV IN= ?.92 LL HYDROLOGIC SOIL GROUP HSG B ° / ___ - _. ___ _-- 102-�- J �� Y lW-99.2t 36 36'RCP INV 0 92.82 loo r- 1'W CONC. HEADWALL &W=95.Of 100 r- . 98- 98�' S` "' TW=95.5f 36'RCP INV.=95.1 I o' 36'RCP DRAIN - - �y / \J6"RCP BW=90 9 91.89 36"RCP INV.=92.80 �� C O M PAR I S O N BOUNDARY sBDH_E \ I (APPROX. LOCATION) APPROX. DRAIN EASMENT 50ER V DESIGNATION �- PLAN BOOK 198 PLAN 67 p/� wes EX. CB FOR BENEFIT OF PIGHLANDER 73A 3 D D RIM-106.80 PLAZA REALTY TRUST 4 L \o` BDH-F 15"RCP INv�s6.9� / WHITMAN FINE SANDY LOAM, 0-3% P�g ;E�tREP 902E Z EXISTING TREELINE �. \ SLOPES, EXTREMELY STONY FOR Q CHATFIELD-HOLLIS-ROCK OUTCROP w R M 106.65 a HSG: D w SUFACE FLOW DIRECTION 15"RCP W-96.95 ! \ \ COMPLEX,G35% SLOPES OC _ OC Ln M , O O q i VJ VJ � i a oo LEGEND OF SYMBOLS C7 O N �I Mll ll 7 11 :. . EXISTING WATERSHED BOUNDARY P4 z 26 e Z W0 Ill CA EXISTING SOIL BOUNDARY p"1 a M p co o o TIME OF CONCEIJTRATION FLOW PATH - ➢ - D - D - . p't"-'•`(/) v`4 SUBCATCHMENT DESIGNATION 1 S . . PR-PARK EX-CB_R 18CN 27=96 HYDROLOGIC SOIL GROUP HSG B Tc=6.0 min 61 ,845 S.F. 1S • - COMPARISON BOUNDARY • • Tc=9.2 min `x' �',_•:__�____ �- -� �, 5. ;-�- - . .-..� -_- -•__. 1 L N:: cMr�� �'_.._- . _�w t _i _ I f DESIGNATION .. 1 4PFaCIx. ^as;1� Snac',ES C ,,, \ PA1�.itF_hT • b rA ev h a EXISTING TREELINE '# T C ! R1.'Jn F;9.87 /� r - v,/ o� 1 r 17 SUFACE FLOW DIRECTION � _ . >+. s I� A i , { r, t t N'S fX Ct3 , , r_ r{ ~~ t I I-- ING Off' 7 r ptly7lNC SU1W ,. ,� •' Rrrt=1.,2.E4 ' 2 � � - FA:!_A!f_"7T ''� b• � A'a.^-- --�".,.._-.t..--.,..^� .+•^r'.�'.,-•-'. - 12"RCP JNV-IV-24 r E Till Ex: Cs RIMS IJ2.99 i 12'RCP ON rN=128.39 PAVDAENT 1 12'RCP AW OUT- � � � _�_ � � A ( 6 AR GAR GE E�. D r,�aTE ✓ ; ��CC I� CS RW=13t.71 /'� �1 h SlI4B 125.0 12'RCP INV W-127.7E /' 12•RCP INV CUT-127.86 OP T PAVRME7.7 r">: Cr3 FAl:a ry t%it,�r.3r. / + - 8 f - ��3k;`act Fea s J {c ,E T �, �,� 10" pvu- j1v A,-125.8'1 __ o P 19S Q a _ - W __ -•\ I RiM 1=1.68 c�� i win 15" RC'' r;';v OUT-i25,b4 E - --"' - f''. I .�' O J ?2" RCP 1NY rN12:i.6K _M N ,810 0 , \�`Fy.�,,,, RCP INV 04-122.65 „� ,5 RC.�..,_C%.'L�':1�V ! -^= .::�.r= ._.._ .._. _'" _!.�:n A ^ �iN 9 / I i - _ V k 1 RCP tNY UUT-120.06� _i?_ _ __ , - -- s ur: I r _ 118.30 M IIIW �' 117so 3 += w I IL C Q Q } R-EAST o f a A �� I 0. TC y / _'--"-f err / �' 45 - �; A� �,�rT 9,555 S.F. I N o `o 0 '\ T C � ➢ � ➢ r ri( RAN f • _I 1 '^ 1 f J ... 4- 4- 3.1 La -a R DAM.57 p �� �. A ~ Y .- > / -I 0 4 j C N=84 oc < U a, a� a STRUCTURE' DA+AAGED '-130.27 .� \ '� 23S A t125,0 "RCP 1NV 114=128.37 L J. L..l-I-1 1lv,I'S=NA " RCA 1NV CUT=125.97 ' TC=6.0 min n W i- is '`� - I- 13U.7 ��_ , 1 'Ry;P ' I C ,+ _�i A I °--i I GA a, O �n �n �n F..,. 8 .C \ -0 LL Nb� ° vt! ?16.7E „ ` R- A y --- !�T�I r-r-I-+.-1 z LU rn o1 a1 �, r. -1 r-r- -T� I a� � c c a ix. ci? \ _� Y ➢ 1S.F C56 0 V I I m Z � ' f5'RCP -�25.r9 c� 27S c=6.0 min. A +123.00 i i 5L 3 u L' o 0 0 L L L 26S ° 6. p ,ate'' T 6.� 1rY ^� f 1 � c CL �► 0 LJ N 28.5 +126.0 125.0+ PR-TRADERSa � �; ,� ,� Tic 2,581 S.F. �• k °o e/ J --6R o 1 CN=77 ���° l�p�r _"24.59 a. .• • 1 P!VFS.FNT zr 1 vSfG S Tc=6.0 min ' 1 NW s d .0 0` 36". LNV OUTf9 % { o s k R lr�+o 24. \� 428 S. T 6.0 fin use BUILDING 7 = a iz > ,- / ` - PR-1 2 BLD 1 �� 24 cN=98 ,� b •o TYPE , x W _ s \ \ I 6.0 mi 5 / R 1 4,452 S.F. x �p -a b ® 12,541 S.F. 32 NITS CN=98 \\ 8S \ , ��o �G pergolc =9v3 ,O Wwa� Tc=6.0 min ` y i ) 6 _ N PR-1 /4 BLD 7 .. • - . \ .,-�• T�C .0 min N �� pool b 11 ➢ Rrll-174..3.q 2,226 S.F. LA •t `TC � A � --.i5"RCF !NV GiLrT.::7Glf.F31 C N=9 8co 00 1 d Gz �1 ,� 5, 70 S. l� O \ \ t Q S- �. Aw R�9R - 1 patio 25S ��,r _ '__ Tc=6.0 min. N N \ = 4 \; ��o i (DISCHARGE TO GRADE) \ \ ec 11 esa \ \ \ 17irA17.05 Ex. oul ~' `�~. , ;.0 ,16.58 9 N0. C= - f r r 1-q 1 J k' -� , 0 36' RCP INV lN=109.75 ,( RCF Xr{K 7 J0.5a 7� ' 19.5 I- L� I G I p 24 RAP UW lr�f70..55 ` 1\ 2 I 2 �, 1 7� t { 1_1 T A_ ' Dh1KSEEnIT �j� V 15"RCP WY 1N�-NA. 20�+ -Li-K� ���- ' 1 38"RCP INV OUT-1V.A. fl 1 1 20S ,9.2 1 1 JOLTER LEVEL. 0 ?07.35 Fcp 8c=1 6 fi9 .1 a a �G �x. ce 15" k\. L1�N2 J E j �R- U RT_ .517S Rr-lfassTc=6.0 min a s 15"RCP 1NY 112.15 -v 0 . 6 9,4 F.70 \ � yl �-- , Tc= 14.5 o F E PR-TRADERSb + -I- -�_ "ie - „� ► 12,251 S.F. 1 •• ° =i=1= - v1 1 I _ 3 cN=83 m „438 24S u.! 10 Tc=6.0 min m 1 I1 -� p G FF=114.75 FF=114.75 A cry /� N RETAIL RETAIL ® 8" ➢ I v l a p� t D a J 4't / ! Y �1 - ~-C a \ 10S �- "��° R �_ _II= _ _ - =1= It PR-1 /4 BLD B LIJ W J �� 3S 2 681 S.F. V Q .� - - T - in •� _I 1 I_ J i i_1: i i_ 1 ._ 1 CN=98 p r %� U _L i_ BUTM NG 6 Q J ,~ + $., Tc=6.0 min. PR-BLDG 2 - 1 y 1 1 4 m I t� 3_ L \ �.,:1,1�.�. 34 NITS .,... 8,905 S.F. t y- 1--'' \�, T a ` ! (DISCHARGE TO GRADE) L � CN=98 FF=117.0 Tc=6.0 min ` 1 NO. 3 rl -r�1 5S a d (/'� LJ 1_IJ t -y-1-1 rJ C) REFUSAL ® 34" P 1 BUILDING 5 .. `I BUILDING 12 2t q 114.98 ,i-1 _ TYPE 2 ` PR--BLDG 5 3 STORY 13S " W " , MAINlA1 PAVEUENT l TYPE 3 �, r• HGH P I 11 1 12S II i t 725 S.F. 32�uNITs "° 1 1 1 '_ # LJ 4 STORY +114. - - 10, m-1�-r�r1 I �f' 00 s 24 UNITS - CN=98 _ ex. CS t. , 1 W/RETAIL 9 h, a- -�: ,� L�_L_�_ PR-FIRST_R R1rA=fos.s5 t " Tc-6.0 min 1 1 1 1 I ; M o m 15`F,CP 1NV 103.10 Q y 1 - - t VIW; _ ,e fTf�r� I.l. 0 c... II l -r-_,-. x,,, /� - , . . ��_��� ,.... 34,294 S.F. Q - - r \ �° 1_I 1 -1 • \ \ 5 ,,JV I:JT ..f4 07. 1!. ` d - I I I 1 3C nV r!xc+:. CN-85 v, L 6J3 t17 r-- F�S!f r r/r; `n;.. W J 3J" rcp wv--t,AZ5STc= min. U Y ^'Y +106.6 l / 113 I .. x • 6 0 m A %21 •� .,. ti.+ /'� FR s�.` R C•''?"D �f!?!r y t1 ' 3L c EX CS r- d .:.ems x ..,, > .,r, ,,,m <.9- •,.:.». R. ,. .,.x.., _. ....w,,. A -. ., '- 7 i a...-..,....-_ ,,....err....n",...-.,.".wwrum.ue+..c«as•rxv.. . .,-..,r.."..R,.:aR........-_ .,".._. ....:_.>..,....,.,...,.._.. .„ .. .. .. vC"� G, .._.8r• fl Q � STREET - FIRST 36"nf.P rhY 701.84 36`RCP 1NV•=701.74 �tr `jT, � f/..• r1 ! 12" 'NATF� �1- I (PUBLIC-50'WIDE� N /�y,/ + �'���'"' R.i■ N s� t tom:x ,. ,.. •._ ,� M... _._ ,... .1 ., . ." .. . "u .,.._ .._.r ...ti., ...,,._.. x »?E .... . _. - ...,. _.M„_- 'FA 71� s u Q v .. c _ l r• �' l 'W CCNrG'. KAr)t'A.i t. � �cC. `� .i£ R s' ANT, 7!v->2.92 u N 3k"f2^P L7.��,+,N' t� ..r`�+5 Je, P.CP 1 11(N x92.B2 (Al Ci CAT!!N Y 3S"lrr P ;�!=3 ,1 F W S RCr' iAll sf. r9 36" ,5r ;N'r=92.8J f , p 't w -�. rz" NcP IM, rrr.Tlct.a; 4L 0 � 1 mot----------•-�x. c� A j RI;j'-7ar,819 aS" Rcr, !NIt 11Var,,r_ l cal 1�• eYlj" RCt f.1V r'i%Tt3.G �^ RAP h�Va86.9' 1hR'' a. FULL 1F W11'1'cr,> m o W �-� NEW ENGL,AND CIVIL ENGINEERING CORP. 265 EM STREET,SUITE 102,P.O.BOX 3026,SALEM,MA 01970 PH:978-741.7401-WWW.ENGINEERINGCORPORATION.COM G . June 12,2018 Ms.Amanda Chiancola Staff Planner Office of Planning and Community Development 120 Washington Street Salem,MA 01970 Re: City of Salem RFQ R-50—On-Call Civil Engineering Support Services,Task Order No. 36 Peer Review Services,40 First Street and 45 Traders Way, Salem,MA Dear Amanda: We are pleased to support the Salem Planning Board with peer review services for the above referenced Project We understand the project will be presented at your next June 21,2018 meeting,we have prepared this preliminary peer review letter for your use at that meeting. We have not completed our detailed review of the Stormwater Report,and supporting pporting plans and documents,and anticipate leaving to revisit a number of areas for review following receipt of additional information from the Applicant. Project Understanding_ • The developer(Peter Lutz/Paval Espinal)proposes a redevelopment project(Traders Village) at the current site of 40 Pirst Street and 45 Traders Way. The project will involve construction of new buildings,parking garages,and related site work and utilities. • The City of Salem requests an independent peer review of the proposed development plans and documentation including.stormwater management, drainage, and on-site engineering utility issues covered by the Environmental Impact Statement. • Included in the peer review will be consideration of existing and proposed utilities, sewer separation and infiltration issues,water main capacity and water valve status, and adequacy of existing utilities to serve the project. . • Peer review will not require compliance with requirements of the Flood Hazard Overlay District special permit. • Specific documents to be reviewed include a Planned Unit Development Special Permit Application(3 pages), a Site Plan Review Application(3 pages);permit cover letter,Project Narrative(2 pages),Environmental Impact Statement(15 pages), Stormwater Report dated 2128/18,Lighting Plan(4 sheets),and a set of Design Drawings dated 3/27/18 (10 sheets); Landscape Plari{5 pages), WATER RESOURCES - BURIED INFRASTRUCTURE PUBLIC WORKS CONSTRUCTION ADMINISTRATION - LAND DEVELOPMENT r • The City of Salem has retained a traffic engineer g eer to review the traffic access, egress,and site circulation issues as well as parking; so those elements are not included as part of this peer review. ' Review Comments: Original submittal Package • 03/22/1 8 =Hard copy set of civil engineering plans, 1.0 sheets 04/09I18 -Hard copy set of landscaping and architectural plans,5 sheets • Site Plan Review Application, 3 pages Planned Unit Development Special Permit Application,3 pates 0 Project Narrative,2 pages Environmental Impact Statement, 15 pages 02/28/18 - Stormwater Report, 339 pages Existing Conditions Plans-Sewer Drain Easement The plans appear to indicate a private utility easement crossing the project along the eastern property line. The project proposes to utilize the sewer pipe but not the drain pipe as part of this project: Not clear on ownership, contributing catchment areas, or use restrictions on this easement or utilities that would impact the project. Request additional information about the utility easement and private utilities in the easement to understand the contributing catchment areas and any potential impacts on the Project. • Watershed Maps Watershed maps are provided to delineate pre and post-development drainage catchment areas (C2.1 and C2.2). Basis.for breaks between catchments are not clear on existing conditions drawings,including breaks between catch ments IS and 3S and limits of existing contributing area from shopping complex and roofs in 1 S. Request clarification that existing complex lots and buildings do not contribute islabeled drainage to site beyond delineated 1 S. Existing catchment areas 4S and SS appear to be m on plans versus the stormwater report,as are catchment 8S and 7S ,model should confirm correct catchments are accounted for. Flow paths corresponding to the time of concentration(Tc)are indicated on most catchment areas,but should be added to proposed 4S and building catchme nts.. Request additional information to facilitate review of stormwater p management plan. an. Existing Conditions Plans Drainage The drainage infrastructure on First Street is shown with incomplete connectivity,including a catch basin and manhole that.do not connect to closed drainage on first street and"approximate"location of a catch basin and 36"drain pipe on the site. Since the project proposes to connect to City drainage in several locations,we recommend the connecti the proposed connection vity be complete in the vicinity of s. ? NEW ENGLAND CIVIL ENGINEERING CORP. Page 2 of 7 • • Request additional information on exist ing drainage and connectivity on First Street abutting project. Proposed Grading and Drainage - . Existing contours are shown on existing conditions plan and watershed map C2.1. Proposed contours are shown on watershed map C2.2. Neither plan shows both pre and post contours. Proposed Utility Plan(Sheet 4,of 11)provides grades for castings but no contours or spot grades. Request spot grades,including top and bottom of curb elevations,be included on the plans. Request plans with(cuts and fills)areas identified or highlighted to facilitate review of drainage alteration and flood hazard overlay permits. • Site Plan Review Application and Planned Unit Development Special Permit Plans required to include: Location and dimensions of utilities,gas,telephone,communication, water,drainage,sewer,and other waste disposal, external lighting,landscaping and screening, snow removal. Plans do.not identify locations of proposed gas,telephone, communication,or.electric(service and for lighting)utilities. Request revised utility plans with proposed utilities,including gas,tel communication,electric service and lighting,and gas meter and electric transformer locations. • Irrigation Plan An irrigation plan is not provided on utility drawings. Request confirmation if irrigation is proposed and provide additional information about irrigation plan piping,connection to City water main,and backflow prevention and metering. Proposed Lighting Plans identify proposed exterior lighting,but do not identify the buried electric lines to the lights or the buildings. Request additional information about proposed buried ele and exterior lights ctric utilities to serve buildings .: • Existing Conditions Plans—Water and Sewer Existing conditions plans do not identify the number, size, or location of existing water mains on Traders Way,and do not clarify the size of the sewer main on First Street(12"or 1511). Existing sewer in utility easement from the shopping center does not include invert el upstream elevation labeled with a ? Pp g elevations, with the " "and the downstream invert elevation labeled with"verify". It is.not clear how much of the adjacent commercial/residential complexes utilize the existing sewer in the easement,so the available capacity p ty is unknown. Request Applicant provide additional information about the number,size,and location of existing water.and gas utilities�abutting project on Frist Street and Traders Way,and -------------- NEW ENGLAND CIVIL ENGINEERING CORP. Page 3 of 7 'L additional information about the service area served by the sewer easement and existing slopes of the sewer in the easement. • ..Demolition Plan. A demolition plan has.not been provided for review: While the demolition onsite is primarily limited to site work,it will be useful to depict the proposed cut and fill areas,limits of tree removal onsite and along City right-of-way, and proposed work to City curbs and sidewalks for curb cuts. Request Applicant provide additional information about proposed demolition on the site and within street layout. • Proposed Utilities-Sewer The plan proposes to utilize existing sewer manholes for connections on First Street and Traders Way,and tapped connections on private sewer in the easement. Request additional information on existing sewer size and slopes to confirmcapacity p (see Existing Conditions Plan—Water and Sewer comment), • Proposed Utilities—Water The plan identifies connecting.to existing City water mains at two locations on First Street and one location on Traders Way. The plans do not identify the locations of the existing water mains on both streets or include connectivity:of water mains with observed water valves. The plan identifies three tapping sleeves with 6-inch valves. The City prefers full bodied tee connections with triple valves unless there are existing operable valves in close connection. proximity to the point of Applicant has proposed to extend a 6-inch water into the site at three locations,and reduce to a 4-inch domestic service connection for each building. The City does not allow fire service and domestic service to share the same water line without separate shutoff valves,the plans do not identify any valves on domestic or fire service feeds or at any junctions throughout the site. The City requests APPlicant consider looping Water feed through the site connecting the First Street and Traders Way connections to improve isolation and limit service interruptions in the future. Request Applicant revise. plans to eliminate tapping sleeve and valve connections,include additional isolation valves in the City Street following review of revised existing conditions plan by City Engineer,add isolation valves on the site including separate fire and domestic shutoff valves for each building,and consider looping the main through the site between First Street and Traders Way. • Proposed Utilities-Drainage Th e design�include s increa sed runoff to Traders Way,catchment 38 includes discharge from 13,000 SF of impervious areas to Traders Way without being intercepted by catch basins within the project limits,raising concerns about sheet flow in the First Street intersection. traveled way and capacity of existing drainage at NEW ENGLAND CML. ENGINEERING CORP. Page 4 of 7 Request Applicant - q pp cant review road shape and existing drainage capacity at proposed curb cuts on Traders Way and revise drainage design to include catch basins onsite or modify street drainage if necessary to prevent drainage problems on Traders Way, • Proposed Utilities-Drainage The d1.esign includes a limited number of catch basins to serve large and fragmented parking lot. It is difficult to observe how the drainage from the larger Parking lots(with parking islands)will drain to single locations without spot grades, contours,and flow arrows if necessary. In addition,runoff received by catch basins may exceed their capacity due to the large catchment areas served(catchment 19S,20S. and 23S for example each discharge 15,000 to 20,000 SF of impervious area to single locations). Without redundant catch basins,the drainage system may become overwhelmed as stretched capacity is reduced due.to trash and vegetation,and may result in surface flooding or ponding. Request Applicant provide additional information to demonstrate how runoff swill travel in the parking lots and review the number and location of proposed draihage catch basins to make sure review proposed drainage catch basin locations and confirm adequate number of structures is provided with consideration for redund ancy fo r reduced inlet ca ac due to trash and vegetation. p �' • Proposed Utilities—Gas Project narrative identifies natural gas as a fuel source for the buildi identified on the plans, ngs but gas piping is not • Request additional information about location and size of proposed gas piping, • Garage Drainage and Roof Drainage Plan includes several small at-grade parking.garages. The garages do not include drainage or oil/water separators prior to connection to sanitary sewer. Request Applicant clarify if garages require floor drains and connections to sanitary sewer per plumbing code. Drainage Alteration Permit(Engineering Dept.) Project includes a number of cut and fill areas,including proposed fills in excess of three vertical feet. As a result,the project requires a drainage alteration permit from Salem Engineering Department. • Stormwater 1Vlanagement'Permit(Planning Dept.) Applicant's.Stormwater Report dated February 28,2018 meets requirements of Stormwater. Management Permit. . .. Stormwater Management Report,Drainage Analysis New.Drains a Out falls—Design includes three new storrnwater outfalls: Two of the outfalls discharge to a wetland resource area and one discharges above grade on First Street. These f. 1VEVtT ENGLAND.CIVIL ENGINEERING Co". Fage5of1 e. F l outfalls do 0 not appear to provide 80%removal of total suspended solids(TSS)in accordance with the Mass Stormwater Policy for new development projects,as described in the Stormwater Report the outfalls propose 44%TSS removal. The outfall.that discharges to grade on First Street provides the required treatment and TSS removal,but is positioned in a location that discharge must flow over sidewalk and roadway to reach the modeled discharge location 4L to 6L. Request Applicant confirm the two outfalls provide treatment and TSS removal in accordance with Mass Stormwater Policy and identify how discharge from outfall adjacent to First Street will reach the drainage system in the street without traveling over the sidewalk and roadway. Pre and Post Runoff. -Design incorporates nine sub surface infiltration systems to detain runoff and increase groundwater recharge. Design incorporates connections to the City drainage on First Street. Detailed review of the Stormwater Report not yet complete. Water Oualit-Design incorporates deep sump catch basins and oil/sediment separators for pre- treatment prior to discharge to nine sub-surface infiltration systems. The Mass Stormwater Policy allows for infiltration if pre-treatment provides 44%o removal of total suspended solids (T ) SS. .The treatment chain proposed.does provide 44%TSS removal;however the proposed catch basins are identified as"shallow CB`s';and oil/sediment separators to not match the configuration and design considerations of the Ol/Sediment Separators in the MassStormwater Handbook(Volume 2, Chapter 2,Page 7), specifically the discharge orifices in the first chamber and the inverted elbow discharge in the second chamber. • Request Applicant confirm the proposed catch basins will provide 4-foot deep sediment summand proposed separators meet the MassStormwater Policy requirements for offline configuration and design considerations. Design incorporates eleven 1,500 gallon .U/sediment separators of the same size, serving catchments of various sizes. Plans provide two details for the same sized separator. Request Applicant confirm all oiUwater separators are proposed to be.the same size. Design includes a limited number of catch basins to collect the runoff from the parkin catchment g lots. The areas served by some of the catch basins is too large to provide adequate treatment and TSS removal per the Mass Stormwater Standards which recommend impervious areas be limited to 1/4 acre for each basin and flows be restricted to less than 3 cubic feet per second. Several basins serve much larger imp ervious pervious areas, for example the single double-grate catch basin is intended to serve a catchment area of over 26,000 sf(over 20,000 sf impervious)and is predicted to convey flows of 3.67 CFS during a 100 year storm. Request Applicant confirm adequate catch basins are provided to_meet the requirements for TSS removal and treatment per Mass Stormwater Standards. Infiltration_Applicant hag provided soil boring/pit information in four locations but has not Provided sub-surface soil information for most of the nine proposed infiltration systems. NEW ENGLAND CIVIL ENGINEERING CORP, Page 6 of 7 D Soil information provided identifies ledge 2-3' deep in three of the four locations and dep th to groundwater is not identified. It appears likely that blasting will be required in most of the locations of proposed infiltration,eight of the nine units identify the bottom of the system as stone,while one unit proposes the bottom of the system as"broken ledge Request additional information about the soil,ledge,and groundwater where the subsurface infiltrators are proposed and clarification on how the infiltration systems will operate(stone versus broken ledge). If you have any questions or require additional information,please do not hesitate to contact me at any time on my cell phone at 978-767-5415 or at my Salem office at 978-741-7401. Sincerely, William M. Ross,P.E. Project Manager/Principal Engineer New England Civil Engineering Corp. Cc: David Knowlton,City Engineer Clients/Salem/TradersWay06.122018 review letter • NEW ENGLAND CIVIL,ENGINEERING CORP. Page 7 of 7 NEW EN GLAND CIVIL, ENGINEE RING CORP. 265,ESSEX STREET,-SUITE 302,P.O.BOX 3026,'SALEM,MA 01970 PH:•978.74:1:7401'--WWW.ENGINEERIN000RPORATION:COM - r X May 3.1, 20.$, Amanda Chiancola Staff Planner Office of Planning and Community Development '120 Washington Street, Salem,MA 01970' Re: City of Salem RFQ R 5'0=On-Call Civil Engineering Support.Services, Task Order No: 3.6- Peer Review Services,4Q First Street,Arid 45.1raders Way, Salem; MA Dear Amanda- We greatly appreciate the opportunity to provide Peer Review Services on behalf,of the City of Salem,, in support of the proposed,°development project at 40 First Street and45 Traders Way: At your invitation, we have prepared this Task Order Letter Proposal to provide peer review services;of the proposed development'. Project Understanding_. • The developer(Peter LutzJPaval Espinal).proposes a re development project(Traders Village) at the current site of 40 First Street.and 45 Traders Way, The_pr . eci will Involve,construction of new buildings,parking garages, and.related site'work and utilities. • The City of Salem requests an independent peer review of the proposed development,plaris and documentation including stormwater management, drainage,Arid on-site engineering utility issues covered by t1ie;Environmental_ in _ipac Statement. • Included in the peer'review will be consideration of existing and'proposed utilities; sewer separation and infiltration issues,water main capacity and water valve status, and adequacy of existing utilities to serve the project: • Peer,review will not require compliance with requirements of the Flood`Hazard`Overlay District special.permit. • Specific:documents;fo be reviewed include.a Planned Unit'Developinerit Special Perm_ it Application(3'pages), a Site Plan Review Application(3 pages),peririit cover letter, Project Narrative(2,p4ges), Eiivifonmental.Impact'Statement(l5 pages), Stormwater Report dated (_"pages),.Lighting Plan(4 sheets); and a set of Design Drawings dated,k7f18 (10 'sheets), Landscape Plan(5 pages); WATER RESOURCES BURIED INFRASTRUCTURE-PUBLIC WORK5 - ;.CONSTRUCTION ADMINISTRATION LAND"DEVELOPMENT 6 o The City of Salem has retained a4raffic engineer to review the traffic access, egress,and site circulation issues as well as parking;.so those elements are not included as part of this peer review: SCOPE OF'WORK:. Task 1) Review.existing City of Salem utility plans,and information in the vicinity of the proposed retail and residential;development at 40 First Street.and.45 Traders Way„ Task 2)A.ttendmeeting with City Engineer and City Planning`Department staff to discuss specific City concerns to be addressed in the peer review.,. Task 3)Review Application for Planned'Unit Development and Site Plan Review;applications: Task 4)Review and compare/contrast previous drainage catchment delineations and stormwater management for existingland proposed facilities. Task 5) Complete site yisit'to observe the number and location of exsting>sewer and,drainage structures; existing"topography and`'mpeivous areas;and existing waterwalves and structures as shown on"Existing,Conditions Plans"by Williams& Sparages. Task 6)Review'Site Plan Review ProjectNarratiwe,`Enviroririental Impact Statement, , and Stormwater. Report(Drainage Report)prepared b_y Williams&Sparages. Task 7)Review site development plans prepared by"Williams&Sparages. Review proposed on-site stormwater management system,pre and.post-development runoff calculations, and stormwater_quantity and quality issues: Review calculations for projected sanitary sewer flows;hydraulic calculations for proposed sanitary sewer design, and layout of'pro ,posed and sanitary sewer piping: Task 8)'Prepare Letter Report summarizing findings of the record search, site walk;document review, and_meeting described in Tasks 1-7 above:` Task 9)Attend up to one(1)meeting.or conference call with engineering representatives of City and Applicant to review the findings of the site walk and review of the documents summarized in Tasks 3-8. Task 10)Review response letter prepared by the Applicant in'response to peer review letter report,and prepare second peer review letter report summarizing jhdL status of the comments from peer review letter report-,(Task 8). Task 11)Plan for and attend up to two Q)Planning Board public hearings to witness the presentation of the project by the Applicant and to present findings of peer review. Expanded SCOPE OF WORK: t NEW ENGIsAND CML ENGINEERING CORP. Page 2 of 4 r l Task 12)If requested liy the City of Salem,provide•additional engineering:services as,required to complete additional site visits,review additional projectplans and doeuments beyond tho e described above,prepare additional peer review letters, and;attend additional`meetings:or public hearings: PROJECT BUDGET:` ' Compensation for the Scope.of work descr bed.in Task 1,through Task 11 shall be'made based on periodic accrual invoices,(time an:,materials),not to,exceed the amount of Seven Thousand Five Hundred D.olIars (57,50�,00.)without written authorization;from the City o'f Salem. Task 12.will be completed on an accrual(time and materials)ba$is at an;hourly rate of$88.00 to $160.00 depending on the labor category required: Writfen direction from the Crty of Salem will be requred'to expand scope ofserviees. PROJECT SCHEDULE:: New England Civil Engineering Corp wilhcomplete the Scope of Services described InTask 1 through. Task 12 above within 20 working days following:receipt of written authorizatioii.'to Pro ed and`copes of all documents to he reviewed a"s described above. PAYMENT TERMS Periodic invoices will be submitted to the Client"and wi11 be based on percentage completion cif individual tasks as descnbed.atiove. Invoices are payable within fourteen(14)days of receipt and approval by Client, EXPENSES< The method for charging expenses, sub-coritrac'ted or,supplemental services is 1 ,15 x the actual cost of:. the.direct;expense. _ ACCEPTANCE. This Task'Ordered letter proposal,in conjunction with the reference Coritract'.RFQ R SO,.will serve as an"Agreement to.Professional Sen, ces" Please"sign this proposal in the space provided and return one executed copy to my attention at your earliest convenience to.initiate t11e project. W"e.have provided five: execution lines for City of Salem author.iidtidh to,proceed but will be happy to revise or append the format of:this letter with additional signature lrnes at=your request: If you have any questions or require additional information,please dd not hesitate to contact me at any time on my cell phone at 978-767-5415 or at thy.Salem office:at 978-, 1-7401: We thank you for the opportunity to work with the_City,of Salem and look forwardao building on our successful and rewarding g partnership moving,forward. Si el Wihiain Ross ,RE - Project Manager%Prmcpal Engineer, Ne<w England Civil Enginee"ring Corp. .�7g+ '. 7k�T/.� ;LAND�-t.��y� .y-�(.�7'gTy. :. - E�W�IVIb c W L�1tl VilV Page 3 of4.. s Task Order No. 36 Authorization: Kimberley Driscoll. Date:: Mayor P Tom Daniel Date: Director of Planning and: C unity Development; id Knowlton,P.E.Date:% City Engineer Tom Watkins Date: Pur sing Agent Elizabeth Re and Date: City Solicitor NEW GLAND CML ENOWEER[NG COS: Page 4 of 4 CITY of SALEM Purchase Order PURCHASING DEPARTMENT rk 120 Washington Street SALEM,MASSACHUSETTS 01970 Fiscal Year 2018 Page 1 of 1 wx TEL(978)745-9595 FAX(978)745-7461 SALES TAX EXEMPTION#E-046-001-413 THIS NUMBER MUST APPEAR ON ALL INVOICES, PACKAGES AND SHIPPING PAPERS. B 200 � Order#Purchase 5007504-00 L PLANNING DEPARTMENT L 978) 745-9595 EXT 5692 120 WASHINGTON STREET 3RD FL T SALEM MA 01970 O V NEW ENGLAND CIVIL ENGINEERING CORP' S PLANNING DEPARTMENT N SALEMM MA 01970 E 265 ESEX STREET, STE 102 H (978) 745-9595 EXT 5692 p 20 WASHINGTON STREET 3RD FL D SALEM MA 01970 O T R p Vendor Phone Number Vendor Fax Number Requisition Number Delive .Reference 978-741-7401 978-741-7402 8280 Date Ordered Vendor Number Date Re wired Freight Method/Terms - -.Department/Location 06/11/2018 15930 06/06/2018 PLANNING Item# Description/Part No. _ _Qty UOM Unit Price Extended Price 1 CIVIL PEER REVIEW 40 FIRST ST&45 TRADERS WAY 1.0 EACH $7,500.000 $7,500.00 -TASK ORDER#36 RFQ-R50 - 24573-5713 $7,500.00 CITY RECORDS INDICATE SUFFICIENT UNENCUMBERED FUNDS ARE PRESENT IN THE BUDGET ACCOUNT. + APPROVED BY �- i 7 � l Thomas P.Watkins Purchasing Agent (NOT VALID WITHOUT CITY PURCHASING AGENTS SIGNATURE) PO Total 17,500.2U 6 T CITY OF SALEM PLANNING BOARD Decision Planned Unit Development,Site Plan Review,and Stormwater Management Permit Decision 45 Traders Way and 40 First Street ; (Map 8,Lot 159 and Map 13,Lot 11). September.X,2018 Findings and Decision Re:Application of Peter Lutts/Pavel Espinal for the properties located at 45 Traders Way and 40 First Street(Map 08,Lot 159;Map 13,Lot 0011)for a Planned Unit Development Permit and a Site Plan Review in accordance with the Salem Zoning Ordinance. Procedural History 1. On Thursday, April 11, 2018 Peter Lutts/Pavel Espinal filed the above referenced . application with the Planning Board. 2. The application proposed the development of the site with 212 residential dwelling units and approximately 7,600 square feet of retail space. '. 3. The Planning Board of the City of Salem scheduled the public hearing for Thursday,.May 3,2018.The meeting was continued to May 17,2018,no testimony was heard 4. The Planning Board opened a Public Hearing for the Planned.Unit Development, Site Plan Review, and a Stormwater Management Permit on Thursday, May 17, 2018. The . hearing was continued to June 7, 2018; June 21, 2018; July 5, 2018, meeting was cancelled due to a lack of a Planning Board quorum; and September 6,2018.The public hearing was closed on September 6,2018. 5. Since the project was initially filed,there have been significant modifications proposed to the plans as a result-of input from the Planning Board and abutters to the site. Specifically, in the course of the review the plans evolved such that the massing of the buildings along First Street and Traders Way have been reduced, the parking has been modified from all surface parking to a portion of the parking placed under the buildings to create more pervious surfaces and greenspace,the clubhouse has been relocated to the center of the site to create a buffer from the residential neighborhoods,a cueing lane has i been added for traffic turning left off Traders Way,the entrance on First Street has been relocated such to ensure there is not a conflict with the egress across the street,a buffer of trees has been added to the Cloister Condominium on First Street which abuts the project and landscaping has been increased particularly along the street frontages. ' 6. Throughout the public hearings,the plans and other submission material were reviewed by the Planning Board. Throughout its deliberations, the Planning Board has been mindful of the statements of the applicants and their representatives,and the comments of the general public,all as made at the public hearing. In considering approval of the Planned Unit Development,the Planning Board finds that the s development meets the criteria of the Planned Unit Development as stated in the Salem i Zoning Ordinance,as follows: Specific Findings A. The Planning Board hereby makes the following findings pertaining to the City of k . Salem Zoning Ordinance,Seca 7.3 Planned Unit Development: 7.3.8.1 The proposed planned unit development is in harmony with the purposes and intent of this Ordinance and the master plan of the City of Salem and that it will promote the purpose of this section. The proposed planned unit development is in harmony with the purpose and intent this ordinance and the master plan of the City of Salem as this project will add vitality to the city by developing the site with a mix of residential units, a" portion of which will be deed restricted as affordable housing, and commercial ! .. spaces generating new tax revenue for the city. The project includes a walking path through the site that will offer a pedestrian connection for the existing neighborhood to the adjacent shopping center, and the applicant will contribute ; funding towards the City's.Transportation Enhancement Fund to address the impact of transportation network services on municipal roads, and other f transportation infrastructure or any other public purpose substantially related to the operation of transportation network services in the city including programs that support alternative modes of transportation:The project also contains a dog park available for residents of the surrounding neighborhood condo associations; a trail system around the wetland for the residents of Salem and various locations suitable for public art. 7.3.8.2 The mixture of uses in the planned unit development is determined to be sufficiently advantageous to tender it appropriate to depart from the normal requirements of the district. a The planned unit development is designed to provide various types of land use which can be combined in compatible relationship"with each other as part of a g ` totally planned..development. As proposed, the compatible relationship among , the mixture of residential, commercial and open space combined with the G inclusion of affordable housing,a walkway that connects the neighborhood to the shopping center,funding to support the city's transportation network, inclusions of a trail around the perimeter of the wetland for residents of Salem and maintenance of the wetland is determined to be sufficiently advantageous to , 2 1 r a - i a render it appropriate to depart from the strict provisions of the underlying zoning classifications. 7.3.8.3 The planned unit development would not result in a net negative I ' environmental impact. The project will maintain the wetland in its natural state and enhance the wetland by including native plantings around the edges. The surrounding area will be € i seeded with a native wildflower seed mix; furthermore, the wetlands will be protected by the active management of apartment community and.will be remain untouched and clean from.trash and debris. The project will also include a modem stormwater management system that will treat stormwater discharges from the.site and comply with the requirements of the Mass Stormwater Handbook.As such,the project is not anticipated to have a significant effect on t the aquatic biota of the waterways or aquatic habitats and will not result in a net a negative environmental impact. Decision 3 3 In view of the foregoing,the Planning Board hereby decided that the aforesaid project meets all 1. the requisite criteria.It is therefore decided to grant a Planned Unit Development(Section 7.3),a € Site Plan Review(Section 9.5)and a Stormwater Management Permit in accordance with Salem Code of Ordinances Chapter 37 to redevelop the site located at 45 Traders Way and 40 First . Street in accordance with the terms and conditions stated below. t 1. Conformance with the Plans a. Work shall conform to the following project plans for 40 First Street and 45 Traders 4. Way, Salem, MA prepared by Williams Sparages, sheets C1.1, C2.1, C2.2, C3.1, C4.1, C5.1, C6.1, C7.1, C7.2, C7.3, C7.4, and C8.1 dated March 27, 2018, revised June 13, 2018,June 27,2018,June 29, 2018,and August 15, 2018; and plan prepared by Seger Architects, Inc., sheets cover,A-1,A-IA,A-2,A-3, A-4,A-S,A-6,R-1, M-1, and M-2 g dated March 12, 2018 and revised August 29, 2018; and landscaping plan prepared by t Michael D'Angelo Landscape Architecture,sheets L0,L1,L2,L3,and L4 dated April 9, 2018,revised September 6,2018 and August 22,2018. ' 2. Amendments a. Any further amendments to the site plan shall be reviewed by the City Planner and if deemed necessary by.the City Planner, shall be brought to the Planning Board. Any waiver of conditions contained within shall require the approval of the Planning Board. t 3. Transfer of Ownership is a. In the event of the transfer of the site as a whole,within five(5)days of such transfer,the Owner shall notify the Board in writing of the new owner's name and address. The 3 I terms,conditions,restrictions and/or requirements of this decision shall be binding on the Owner and its successors and/or assigns. - 4. Affordable Housing a. Twenty-one (21) housing units shall be set aside as affordable housing units. The Applicant shall place an Affordable. Housing Restriction on these twenty-one (21) housing units in the form acceptable to the Commonwealth Department of Housing and Community Development (DHCD). The restrictions shall be in accordance with the eligibility criteria for DHCD's Subsidized Housing Inventory for the purpose of ensuring that the twenty one (21) dwelling units will be restricted as affordable housing for households whose annual incomes are.eighty percent (80%) or less of Area Median Income ("Low Income Households") with a sales or rental price affordable to said households as determined by DHCD for a period of ninety-nine(99)years from the date }. of the original conveyance. The Affordable Housing Resiriction(s) shall be registered 1 with the Essex South Registry of Deeds. j - 5. Traffic a. The owner shall tender$212,000 to the City of Salem Transportation Enhancement Fund i (TEF). The TEF will be used by the city for transportation network services relating to infrastructure and or operation of the transportation network. b. h owner shall designate a member of.the leasing staff as a transportation coordinator. -..: Commented[AC1]: conditions b-g are from the TlA,pg.32. The transportation coordinator shall be responsible for disseminating relevant transportation demand management information to residents and commercial building tenants, including provisions of a tenant.manual that provides information on public transportation services, routes and schedules, bicycle parking, parking policies and site amenities including car sharing spaces and preferential parking. c. Bicycle parking shall be provided for residents and visitors and shall be conveniently r located for visitors and employees proximate to building entrances. d. The owner shall designate parking spaces on the site for use by a car sharing services such as zipcar. e. Preferential parking locations for residents who use low-emission vehicles will be provided.A charging station for electric vehicles will also be provided onsite. a f. The project shall provide unbundled parking leases for residential units: Residential a tenants shall have the option to lease parking spaces separately from the dwelling units or i to opt out of leasing parking spaces. g. The owner shall post area maps that highlight walking and bicycle routes to promote walking and bicycle travel to and from the site and area businesses,recreational facilities and transit stops. 6. Landscaping a. An as built.landscaping.plan accompanied with a letter from:a Registered Professional Engineer or landscape architect certifying compliance of the •landscaping with the ; approved plan shall be submitted to the City Planner prior to issuance of the Certificate of Occupancy. 4. b. Maintenance of all landscaping on the site shall be the responsibility of the Applicant;its successors or assigns,and any tree or shrub that does not survive shall be replaced. 7. Lighting a. A final lighting plan shall be submitted to the City Electrician for review and approval 1 prior to the issuance of a building permit. b. Light trespass onto adjacent parcels/rights of way shall be avoided as indicated on the photometric plan. 8. Maintenance a. Refuse removal,ground maintenance and snow removal shall be the responsibility of the applicant. "Refuse removal" includes recycling, which shall be the responsibility of the owner,his successors or assigns.The owner shall provide adequae facilities to ensure all users are able to recycle their trash. Owner is to enter into a contract with a.company of ; the owner's choice to arrange pick-up of recyclable material.A copy of this contract is to be submitted to the City Engineer. w b. Winter snow in excess of snow storage areas on the site shall be removed off site. 3 9. Fire Department a. All work shall comply with the requirements of the Salem Fire Department. x ry 10.Building Inspector i .a. All work shall comply with the requirements of the Salem Building Inspector. . 11.Board of Health a. The owner shall comply with the following specific conditions issued by the Board of Health: b. The individual presenting the plan to the Board of Health must notify the Health Agent of the name,address,and telephone number of the project(site)manager who will be on site , and directly responsible for the construction of the project. c. If a DEP tracking number is issued for this site under the Massachusetts.Contingency i Plan,no structure shall be constructed until the Licensed Site Professional responsible for the site confirms that the site meets the DEP standards for the proposed use. d. A copy of the Licensed Asbestos Inspector's Report must be sent to the Health Agent. e. A copy of the Demolition Notice sent to the DEP,Form BWPAO6,must be sent to the Health Agent. f. The developer shall give the Health Agent a copy of the 21 E report. l g. The developer shall employ a licensed pesticide applicator to exterminate the area prior to construction, demolition, and/or blasting and shall send a copy of the exterminator's # exterminator's survey report,treatment plan and treatment reports to the Health Agent. i h. The developer shall maintain the area free from rodents throughout construction. • r �j i. The developer shall submit to the Health Agent a written plan for dust control and street " sweeping which will occur during construction. j. The developer shall submit to the Health Agent a written plan for containment and removal of debris, vegetative waste, and unacceptable excavation material generated during demolition and/or construction. k. Noise levels from the resultant establishment(s) generated by operations, including but not limited to refrigeration and heating, shall not increase the broadband sound level by more than 16 dB(A)above the ambient levels measured at the nearest abutting residential E .property line. 1. The developer'shall disclose in writing to the Health Agent the origin of any fill material needed for the project. r , . 'm. The resultant establishment shall dispose of all waste materials resulting from its operation in an environmentally sound manner as described to the Board of health. n. The drainages system for this project must be reviewed and.approved by the Northeast Mosquito Control and Wetlands Management District. o. The developer shall notify the Health Agent when the project is complete:for final inspection and confirmation that above conditions have been met. 12.City Engineer Y t Q,.,�N PW(diol 6�N� a. All work shall comply with the requirements a City Engineer. 4.b. 'A Licensed Professional .Civil Engine 'shall provide.a to the Engineering` g P _ Department stating that the drainage i astructure to s `ce the proposed development i S has adequate condition and capacity Back-up da cluding complete pipe inspection and structure cleaning of the buried drain structures on First Street and a video inspection from Traders Way to the East boundary of the property Frist Street1to confirm drain connectivity on First Street.Applicant shall resubmit results of the CCTV and revised plans to include.Sheets 4 and 5 to the City Engineer for review and approval prior to ✓ 11 issuance of a foundation permit. c. Prior to issuance of a foundation permit,the applicant shall submit a revised utility p to the City Engineer for review and approval.The revised plan shall include all proposed I utilities including: gas, telephone, communication, electrical service, lighting and gas meter and electric transformer locations,irrigation piping,connection to City watermain, backflow prevention,and metering prior to issuance of a foundation permit. d. Prior to issuance of a demolition permit,_the applicant sha11 revise the demolition plan (sheet 12)to the City Engineer for review and approval. The revised plan shall include �. the limits of curb and sidewalk work to be removed'and replaced on First Street and Traders Way. l/cN✓ e. Applicant shall revise sheet 5 of the civil plan set to include another 2-inch4ate�the � �n East side of Building 6 connections on First Street to isolate the project from the rest of First Street. f Prior to issuance of a foundation permit,the application shall submit a plumbing plan to the City Engineer for review and approval.The plumbing plan shall delineate the number 6 r t and location of floor drains and piping in the garage discharging to the oil/water separator R and the location of vent piping for the separator in the building.The plumbing plan shall also include out .protection for all proposed roof drains that discharge to the wetlands i or the ground and shall demonstrate that the entire roof drainage can be collected and conveyed to the subsurface systems,as shown on the civil drawings. y u g. .The applicant shall submit the results of the remaining sub-surface investigations for all proposed sub-surface detention or infiltration systems in their final locations to the City Engineer along with design changes to configuration or location of sub-surface storage and infiltration units;prior to receipt of a foundation permit. h. A Licensed Professional Civil Engineer shall complete cleaning and CCTV inspection of City sewers,from points of connection on Traders Way and First Street to the interceptor sewer at Mo- ey and Highland Avenue. The video and report of the video shall be submitted to the City Engineer for review and approval. The applicant shall address the rhN R capacity,condition and/or infiltration issues prior to the issuance of a building permit i J RR i. Prior to issuance of a building permit,the applicant shall provide a narrative to the City l Q Engineer regarding protection and enhancement of the wetland resource and calculations1 on pre and post development flows entering the wetland resource. 1 13.Clerk of the Works _ l a: A Clerk of the Works shall be.provided by,the City,at the expense of the applicant,hisv' t successors or assigns,as it is deemed necessary by the City Planner. Notwithstanding the foregoing the parties acknowledge the Project shall be subject to controlled construction which requires oversight by a Registered Professional Civil Engineer. Accordingly,it is j /' # the understanding of the Board,the City.Planner and the Applicant,that the Clerk of the Works; is expected to oversee and review all civil/site improvements related to the Project,including,but not necessarily limited to: i. all utility cut and caps related the City's Demolition Permit; R ii. all new utility installations; XAt iii. any connections to,extension of,or improvements to publicly owned infrastructure both on the applicant's site or within the City's right of way and any on-site stormwater or wastewater systems; iv. any new installations or modifications to existing pavement/sidewalk/curbing;and v. any conditions placed on the project by an order of conditions from the Salem Conservation Commission. ° b. The Clerk of the Works'-shall review and approve all proposed,or approved, changes to � the original Planning Board decision. c. It is also mutually understood that the expense associated with the Clerk of the Works shall be for a reasonable number of hours and at a customary rate of service. d. The applicant shall submit a construction plan that includes a detailed sequence and .schedule of all construction activities related to the Project to the City Planner for l approval prior to starting work. The construction plan shall clearly detail the sequencing, schedule*and duration of all construction activities related to the Clerk of the Works' i y i purview:.Once the construction plan is approved"it shall be used to create a Task Order s for the Clerk of the Works. 1 e. No work, including blasting, demolition, excavation, and grading shall start'before an approved task order for tthe- Clerk of the Works services has been agreed upon and approved by all parties. .' , 14.Construction Practices, 1 a. All construction shall be carried out in accordance with the following conditions: i. All provisions in,the City of Salem's Code of Ordinance, Chapter 22, Noise ; Control,shall be strictly adhered to. '# ._ ii. All reasonable action shall be taken to minimize the negative effects of + i construction,on`abutters. Advance.notice shall be provided to all abut•.ers in writing at least 72 hours prior to commencement of demolition and construction of the project., £ iii. Drilling and,blasting'shall be limited to Monday-Friday between 8:00 AM until 5:00 PM. There shall be no drilling,blasting or rock hammering on Saturdays, Sundays, or.holidays. Blasting shall be undertaken.in accordance with all local and state regulations. a ' s iv. All construction will occur on site;no construction will occur or be staged within p City right of way. Any deviation from this shall be approved by the Department of Planning&Community Development prior to construction. V. A construction traffic management plan and schedule shall be submitted to the [" Department of Planning & Community Development for review and.approval ' prior to'the'issuance of a building permit. vi. Any roadways, driveways,. sidewalks, or landscaping damaged during ) construction'shall be restored to their original condition by.the applicant. 1 vii. All construction vehicles shall be cleaned prior to leaving the site so that they do •'` . _� not leave dirt and/or debris on surrounding roadways as they leave the site. viii. All construction shall be performed in accordance with the Rules and Regulations of the Planning Board,and in accordance with any and all rules,regulations and • ordinances of the City of Salem. ix. All construction vehicles left overnight at the site,must be located completely on the site. X. All construction activities shall be in accordance with the"Salem Police Station t Construction Management Plan xi. All construction shall take place under the direction and supervision of a Licensed Site Professional in compliance with the rules and regulations of the Massachusetts Department of Environmental Protection. t xii. The applicant shall promptly notify the Board of Health of any environmental condition encountered during construction that may adversely impact the abutters s to the site. l 15.As-built Plans 1 8 W� t I 1 ' At a a. As-built Plans,stamped by a Registered Professional Engineer,shall be(,bmitted to the Department of Planning and Community Development and Department of Public I Services prior to the issuance of the Certificate of Occupancy.-- b. The As-Built plans shall be submitted to the City Engineer in an electronic file forma suitable for the City's use and approved by the City Engineer,prior to the issuance of the . Certificate of Occupancy. I c. A completed tie card, a blank copy (available at the Engineering Department) and a D I certification signed and stamped by the design engineer, stating that the work was 1 'K completed in substantial compliance with the design drawing must be submitted to the City Engineer prior to the issuance of the Certificate of Occupancy; as well as, any subsequent requirements by the City Engineer. 16.Violations a. Violations of any condition shall result in revocation of this permit by the Planning Board,unless the violation of such condition is waived by a majority vote of the Planning Board. ' I hereby certify that a copy of this decision and plans has been filed with the City Clerk and copies are on file with the Planning Board. The Special Permit shall not take effect until a copy of this decision bearing the certification of the City Clerk that twenty(20)days have elapsed and no appeal has been filed or that if such appeal has been filed, and it has been dismissed or denied,is recorded in the Essex South Registry of Deeds and is indexed under the name of the owner of record is recorded on the owner's Certificate of Title. The owner or applicant,his successors or V �� assigns,shall pay the fee for recording or registering. Ben J.Pderson Chairman KV 9 CITY OF SALEM Purchase Ordel i PURCHASING DEPARTMENT l 120 Washington Street i SALEM,MASSACHUSETTS 01970 Fiscal Year 2019 Page 1 of 1 . TEL(978)745-9595 FAX(978)745-7461 SALES TAX EXEMPTION#E-046-001-413 i "ufufBE#F�uST APP�AR�AtC 1NU010E5 _„�;;�� PJ�GfCAGESANDtSFi1P,P GPAPERS� "]"B200 Purchase PLANNING DEPARTMENT Order# 6000469-00 (978) 745-9595 EXT 5692 120 WASHINGTON STREET 3RD FL SALEM MA 01970 V NEW ENGLAND CIVIL ENGINEERING CORD PLANNING DEPARTMENT E; 265 ESSEX STREET, STE 102 N. PO BOX 3026 (978) 745-9595 EXT 5692 SALEM MA 01970 P 120 WASHINGTON STREET 3RD FL SALEM MA 01970 R; " .' �=�." ,� '�". .�. .�-.:. �` ..'"' �', a-s •n-.aw .�•'�• -. } � -d`fie! �'�_ -'-,rti< Vendor P on�� ber or�lsax ulnelt. ulsitlon: umtie rliu6y° �fe>'enc 978-741-7401 978-741-7402 194 07/12/2018 15930 07/02/2018 PLANNING tern Y{Des r �IQi1/P-No � � - � Fps �� �� �, 14 .tJ`..# �e<. ExEencle Sri e; 1 CIVIL PEER REVIEW 40 FIRST ST AND 45 TRADERS 1.0 EACH $7,500.000 $7,500.00 WAY TASK ORDER#36 REPLACES PO#5007504 24573-5713 $7,500.00 CITY RECORDS INDICATE SUFFICIENT UNENCUMBERED FUNDS a - ARE PRESENT IN THE BUDGET ACCOUNT. APPROVED BY E �{i' m.