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HomeMy WebLinkAbout2017-04-18 Request for Order of Conditions I r: 00 Ovhb. February 17, 2017 Ref: 11625.09 Andover Conservation Commission 36 Bartlet Street Andover, Massachusetts 01810 Re: Request for Amended Order of Conditions Merrimack College North Campus Development -Academic Buildings A&C and Sakowich Campus Center Expansion DEP File No. 90-0750 Dear Commissioners, On behalf of Merrimack College,Vanasse Hangen Brustlin, Inc. (VHB) respectfully submits this Request for I an Amended Order of Conditions(DEP File#90-0750). The original Order of Conditions (OoC)was issued by the Andover Conservation Commission on October 5, 2001 for the Merrimack College Master Stormwater Management Plan,and last amended in August 2016 for the North Campus Development, Academic Building, modifications, North Campus Project History: The College is proposing to make modifications to the previously approved, "North Campus Development" and "North Campus Academic" projects, and a corresponding Context Plan has been included as sheet C-2 within the Site Plans for additional clarification. The initial North Campus Development project, approved in July 2014, consisted of four(4) new residential buildings and a student commons building on an approximately 4.8-acre site along Flaherty Drive; north of the Sakowich Student Center and west of Austin Hall. Of this approval,two (2) of the proposed residential buildings were constructed under the first phase of activities. The North Campus Academic modifications, approved in August 2016, revised the remaining three(3) buildings along Rock Ridge Road to accommodate academic uses instead of the previously approved residential and student commons buildings. Of this approval, the one(1) central academic building of the remaining permitted three(3), has proceeded into construction under the second phase of activities, referenced herein as Academic Building B. 101 Walnut Street PO Box 9151 Engineers I Scientists I Planners Designers Watertown,Massachusetts 02471 P 617,924.1770 vt:t,tLo,1I;-,D ev. 0", F 617,924.2286 ,ti , ,d,d a,I':„f Andover Consentation Commission Ref: 11625.09 N/I February 17, 2017 Bob Ift Page 2 This request for an Amended Order of Conditions at the North Campus Projects includes proposed modifications to the two (2) remaining Academic Buildings A&C, as well as a proposed expansion to the Sakowich Campus Center, summarized as follows: ■ Academic Buildings A&C Buildings A&C are proposed to extend the building footprints within the prior established site boundaries,as a result of evolving program needs for the academic space. The intent of the site layout, grading,stormwater management and utility corridors and connections remains unchanged from the previous Conservation Commission approvals and plans reviewed with Andover DPW. Hardscape areas have been modified slightly to accommodate the change in footprints. The proposed berm along the back-side of Buildings A, B and C remains to capture drainage from flowing towards Rock Ridge Road. The stormwater runoff from the buildings and adjacent hardscape areas would continue to be diverted to the subsurface infiltration system installed in part under Phase 1,which is ultimately tributary to the Elm Street Detention Basin. As the footprints have increased in size,although within the same project limits, these modifications will result in an increase of impervious area from the prior approvals,therefore supporting drainage calculations are provided and updates to the Peak Flow Credit banking system are outlined in this memorandum. A summary of the drainage updates is included in the Regulatory Compliance section below. ■ Sakowich Campus Center Expansion The Applicant is additionally proposing to construct an expansion of the existing Sakowich Campus Center. The proposed addition consists of a 1-story, 6,700 s.f. expansion to the College's current student dining facility. This expansion will include an exterior patio area along the east side,facing Deegan Walk. The Site of the expansion is bounded by the existing Sakowich Campus Center building to the south, Deegan Walk to the east, Flaherty Way and the remaining North Campus Development Site to the north, and the Sakowich loading dock to the west. The expansion extends northerly from the existing building and provides a pedestrian connection to Flaherty Way in alignment with the wide pedestrian path included in the North Campus Academic project. An overlay of the previously permitted North Campus Development compared with the current proposed design is included as an attachment to this memo, Figure 1--North Campus Academic Overlay. Stormwater Regulatory Compliance: ■ Hydrologic Analysis Condition 5.4 of the OOC states "remaining peak flow credits will be tracked informally by the Commission offices and formally documented in an Amended Order of Conditions..." Pursuant to this condition, the College is submitting this Amendment request in order to track the remaining 1�.1I„i:i,-,�ll'Jaf LU ll[t5[3�EFK.i ts{ iedEif O,>C 7,.ilii Giii,rhsleii �� �.ie;t l:a I 9 Andover Conservation Commission ���60� fief: 11625.09 � feiaruary 17, 2017 Page 3 stormwater peak flow credits that were banked through construction of the football field and Elm Street detention basins. While the hydrologic design points remain unchanged from the previous analysis, the watershed boundaries have been updated to reflect the following: - Burke Road Drainage Improvements: In coordination with the Andover DPW, following initial Conservation Commission approval of the North Campus Development, the College provided a series of drainage improvements to the existing parking lot north of the site and south of Elm Street. This included the installation of bituminous berm curb, two (2) double-frame catch basins, and a new water quality structure to capture stormwater runoff that was previously tributary to Rock Ridge Road and Elm Street,and divert it to the Elm Street Basin via the existing 48" pipe. SKC-25 — Drainage Improvements at Burke Road is included as an attachment to clarify these drainage improvements. These improvements resulted in a substantial drainage improvement to the Rock Ridge Road system, but in doing so have diverted additional flow to the Elm Street Basin. The watershed boundaries in the proposed hydrologic model have been updated to account for this diversion, and the associated peak flows accounted for in the updated credit summary. - Sakowich Campus Center Expansion: While the drainage patterns of the site of the Sakowich Campus Center Expansion mimic that of the original model, the watershed boundaries have been extended to include the full limits of the proposed modifications. In order to most accurately represent the progression of site hydrology from the existing conditions originally modeled circa July 2014,through these proposed modifications,the full hydrologic model of the sitewas re-evaluated, and the peak flow credit summary was updated(see Table 3 below). The updated model, compares the existing conditions of the project site prior to any of the North Campus development (201.4), to the proposed conditions which include the North Campus Phase 1 residential buildings, Academic Buildings A, B and C, Sakowich Campus Center Expansion, Burke Road drainage improvements and associated hardscape areas. Supporting Existing and Proposed Conditions Drainage Figures,and associated HydroCAD reports are included in the attachments to this memorandum. The rainfall-runoff response of the Site under these existing and proposed conditions was analyzed for storm events with the recurrence intervals of 2, 10, 25, and 100-years, The rainfall depth values used in the analysis are consistent with the approved Stormwater Master Plan. The results of the analysis, as summarized in Tables 1 and 2 below, indicate a significant decrease in peak discharges rates to design point DP-IA-1B(Rock Ridge Road)of 19.7 c.f.s in the 100-year storm. The increase in peak flows to design point DP-ELM-1. (the Elm Street Basin) equates to 25.8 c,f.s., which is proposed to be deducted from the Stormwater Master Plan Peak Flow Credit, as shown in Table 3. , il.,.i,-l':,11.�31fS l;e:i.i.irl.S Anti ii li.i C:t I: r!ioC.iiIn Ar.i3i i.[I;i.. :i t 1: Andover Conservation Commission Ref: 11625.09 February 17,2017 Page 4 TABLE 1- Peak Discharge Rates(cfs) &Volumes(cf)-Existing Conditions Design Point 2-year 10-Year 25-year I00 year DP-ELM (Elm Street Basin) Rate(cfs) 6.8 12.5 15.0 17.2 Volume(cf) 25,029 46,150 55,625 64,180 DP-1A-1B(Rock Ridge Rd) Rate(cfs) 8.1 16A 20.2 23.5 Volume(cf) 30,676 59784 73064 85,150 TOTAL Rate(cfs) 14.9 28.9 35.2 40.7 Volume(cf) 55,705 105,934 128,689 149,310 'CABLE 2- Peak Discharge Rates(cfs) &Volumes(cf)-Pro eased Conditions* Design Point 2-year 10-year 25-year 100 year DP-ELM (Elm Street Basin) Rate (cfs) 18.2 31.9 37.8 43.0 Volume(cf) 63,835 113,287 135,191 154,878 DP-1A-1B(Rock Ridge Rd) Rate(cfs) 1.1 2.3 2.9 3A Volume(cf) 3,859 7,839 9,688 11,378 TOTAL Rate(cfs) 19.3 34.2 40.7 46.4 Volume(cf) 67,694 121,126 144,897 166,256 TABLE 3 - Peak Flaw Credit Summary by Project Net Increase in 100-yr Remaining Peak Flow Project Date Peak Rate(cfs) Credit Sophomore Housing 2/2002 3.4 58.60 Lot D Parking Lot Extension 3/2003 11.5 47.10 Monican Boulevard Relocation 5/2004 -2.54 49.64 Game Field Renovations 3/2005 0.00 49.64 Elm Street Entrance 5/2006 -0.69 50,33 Volpe Center Expansion 1012011 1.6 48.73 Student Residences Project 7/2012 4.4 44.33 Develepmen�* " 14.14 30.29 * 8POI-6 88 39-.2-8 North Campus .Updated'Phase Residential.Academic Buildings 2/2017 +: 25.8 18.53 A,B,C and SakoWich Ex' ansion 'Peak Flow Credit deducted from 712014 and 812016 North Campus superseded by current updated modet as noted above. Lbtil]G25O]yreyoin A r.,AdooC Rudh C3„�>s nr mlengr,.qax far Andover Dmsewoion(ommioion ' mx: lI62Slm rcu,*m,yl7.20l, ~=�� pv9e5 q�y � ��-� � Hydraulic Anal As noted abovw, theotnrmvva1er management design is consistent with the prior approvals. Based on the modifications to impervious area and fine grading, the closed drainage system calculations have been updated to confirm that the drainage pipe networks are sized sufficiently tu carry the capacity ofotnrmwmtorflows. A summary of the updated hydraulic analysis |u included |n the attached supporting calculations. � The project proposed to continue to utilize the subsurface |nf||tmdnn system installed under Phase 1in order to provide stormwmtorrecharge. Additional runoff from the expanded Buildings A and C footprints, as well as the Sakowich Campus Center is diverted to this system, and therefore the design proposes to provide additional subsurface chambers |n order to meet the required recharge volumes. Recharge calculations have been prepared with regard to both the Town of Andover Stormwater Regulations as well as the k4assDEPStormwater Handbook. Recharge volume for the proposed � project is provided based Upon the more stringent of the two. Supporting calculations for the � additional chambers required for Academic Buildings A and C and the Sakowich Campus Center � � Expansion are included in the attached supporting calculations, In accordance with the Act and Bylaw, abutters within 100 feet nf the site have been notified of this Request via certified return-receipt mail on this date.A copy of the abutter notification form ! and a list of abutters are attached to this request, Receipts of the mailing will be provided at the public hearing. Please advertise this matter for public hearing at your March 7,2017 meeting of the Conservation � � Commission. Should you have any questions concerning this submittal or require additional information, please contact meat (6l7) 607'O004. Sincerely, VanassoHmngen Rruod|n,lnc ! / ! ]effKoottoritz, P.E. � Senior Project Eng|near | i � a ."C m,*,.,'.^~^~.°~... A..^^..^.*^.a~. �.^.. / nn y Andover Conservation Commissions Ref: 11625.09 February 17,2017 fig# hb Page 6 ATTACHMENTS: Site Plans: - C-1 Legend and General Notes - C-2 North Campus Context Plan - C-3 Layout and Materials Plan - C-4 Grading and Drainage Plan - C-5 Utility Plan - C-6 Sanitary Sewer Plan and Profile C-7.1 Site Details 1 - C-7.2 Site Details 2 - C-7.3 Site Details 3 C-7A Site Details 4 C-S3 Layout and Materials Plan C-S4 Grading and Drainage Plan C-S5 Utility Plan SV-1 Existing Conditions Plan of Land Figures: - Figure 1 North Campus Academic Overlay Figure 2 Existing Conditions Drainage Areas - Figure 3 Proposed conditions Drainage Areas SCK-25 Burke Road Drainage Improvements Supporting Calculations: - Attachment A—Hydrologic Analysis o Existing Conditions HydroCAD Report o Proposed Conditions HydroCAD Report - Attachment B—Hydraulic Analysis—Closed Drainage System Calculations - Attachment C—Stormwater Recharge Calculations Abutters List and Notification tft,\.:Cf\lV,IT LO IH25i %A,1( lfi C),C f:,&I -�'i�=�s At.:'.lriii'[1��.E��i—st� nI-Idl,ta:all 14coy,;r1n:s "-„a .. R i i IE I i i IBb: M-1 1 Bb M-E M-1 M-1 -1 Ba X-P DP-ELM-1 Austin I=ield Depression DP-IA-18 Elm Street Bas' Roc Ridge Road/Elm EX-R St et Drainage System Overflow from Depression Site Total �ca Reach on j�j( Routing Diagram for 11626.09-EX ❑ Prepared by VHB, Printed 2J2112017 HydroCAD®10.00-18 s!n 01038 ©2016 HydroCAD Software Solutions LLC 11625.09 - EX Prepared by VHB Printed 2/21/2017 HydroCAD810.00-18 sln 01038 ©2016 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 298,010 74 >75%Grass cover, Good, HSG C (1, 1 Ba, 1 Bb) 127,115 98 Impervious (1, 113a, 113b) 426,126 81 TOTAL AREA 11625.09 - EX Prepared by VHB Printed 2/21/2017 H droCAD@)10.00-18 sln 01038 02016 H droCAD Software Solutions LLC Page 3 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Su (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover Nu 0 0 298,010 0 0 298,010 >75%Grass cover, Good 0 0 0 0 127,115 127,115 Impervious 0 0 298,010 0 127,116 426,126 TOTAL,AREA i i i i 11625.09 - EX Type III 24-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 s/n 01038 02016 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 1: M-ELM-1 Runoff = 6.80 cfs G 12.16 hrs, Volume= 25,029 cf, Depth> 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR Rainfall=3.36" Area (sf) CN Description 67,980 98 Impervious 104,835 74 >75% Grass cover, Good, HSG C 172,815 83 Weighted Average 104,835 60.66% Pervious Area 67,980 39.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 1.1 125 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 80 0.1000 5.09 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.0 135 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 50 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 260 0.0060 5.58 17.52 Pipe Channel, 24.0" Round Area= 3.1 sf Perim= 6.3' r=- 0.50' n= 0.013 Concrete pipe, bends &connections 0.4 155 0.0060 7.01 34.42 Pipe Channel, 30.0" Round Area=4.9 sf Perim= 7.9' r= 0.63' n= 0.012 HDPE 0.9 675 0.0100 12.38 155.61 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 0.7 390 0.0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 11.0 1,920 Total 11625.09 - EX Type /I/ 24-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/2112017 HydroCADVIO.00-18 s/nO1038 02016 HydroCAD Software Solutions LLC Page 5 Subcatchment 1: M-ELM-1 Hydrograph 7 7-; Type III 14�0 Rain al -ku 6oif Arel a=l 72,�1-5 Sf I Runoff' �oiu�neIr--25 11926 cf -,I- j Ruooff-Deoth>1.74 4- I E LL 3 CN=83- - l - 2- . . .......... ...... .... 0- 0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type Ill 24-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 hydroCAD010.00-18 s/n 01038 O 2016 h droCAD Software Solutions LLC Pape 6 Summary for Subcatchment 1Ba: M-1A-1Ba Runoff — 8.14 cfs @ 12.12 hrs, Volume= 27,373 cf, Depth> 1.52" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR Rainfall=3.36" _... Area (sf) CN Description * 55,450 98 Impervious 160,100 74 >75% Grass cover, Good, HSG C 215,550 80 Weighted Average ae 160,100 74.28% Pervious Area 55,450 25.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 4.2 50 0.0400 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 3.6 430 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 f s 7.8 480 Total Subcatchment 1 Ba: M-IA-1 Ba Hydrograph E ! I E 8.14 CIS I g- ' Type III 241hr, E - € 1 E 1 I f € f F [ I I 7- 2=YR Raanall.=3::3G" ; - -- , -Runoff Area 215,550 sf - Runoff Volume#27,373 cf . ,/_1�' .y_/_.�_--__1_;'.-::" ..._�.__`___E__J__ I.-. - l Runoff V epyT4�■��y>1.5L'•I 4_ _flow Deng#h 4$0,,_- F Tc7.3 m 1 I ! t GI�! V]^^]((O I I I I I 1 I 1 I 3 I ! I 1 I 2' 1 E I I 1 : I ' 3 f I 3 I 1 I 1 I I i 1 I - / I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i 11625.09 - EX Type /it 24-hr 2-YR Rainfall=3.36° Prepared by VHB Printed 2/21/2017 Fi droCAD010.00-18 s/n 01038 ©2016 H droCAD Software Solutions LLC Page 7 Summary for Subcatchment 1 Bb: M-1 A-1 Bb Runoff = 1.20 cfs @ 12.10 hrs, Volume= 3,870 cf, Depth> 1.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR Rainfall=3.36" j Area (sf) CN Description 3,685 98 Impervious 33,075 74 >75% Grass cover, Good, HSG C 36,760 76 Weighted Average 33,075 89.98% Pervious Area 3,685 10.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftlsec) (cfs) 5.0 Direct Entry, Minimum Tc 5.0 0 Total, Increased to minimum Tc= 6.0 min Subcatchment 1 Bb: MA A-1 Bb Hydrograph , E 1 1 1 1 1 E I I I I I E 3 a5 Type '.III ;24-0 -2-YR Rainfall=3.36"' T- - - 1— Runoff Arta=36,760 sf 3 I I ! I ! Runoff Vo)u�ne=3,870', cf f 3 I I I D 3 Runoff epthI �1.26'' p Tc=6.0 rnit� W G7,6 !� 7 1 � f I 1 I 1 I I 3 3 1 I ! 3 ! 3 1 1 1 I 1 1 3 I 1 ! } 3 3 I I I 1 11 0— k '. k..-e.- e - 0 1 12 3 4 5 fi 7 8 9 '10 11 12 13 14 15 1fi 17 1$ 19' 20 21 22 23 24 Time (hours) 11625.09 - EX Type Ill 24-hr 2-YR Rainfali=3.36" Prepared by VHB Printed 2/21/2017 H droCADO 10.00-18 sin 01038 ©2016 H droCAD Software Solutions LLC Page 8 Summary for Reach EX-R: Overflow from Depression Inflow Area = 36,760 sf, 10.02% Impervious, Inflow Depth > 1.09" for 2-YR event Inflow -- 1.02 cfs @ 12.16 hrs, Volume= 3,350 of Outflow - 0.66 cfs @ 12.50 hrs, Volume= 3,303 cf, Atten= 35%, Lag= 20.3 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 0.55 fps, Min. Travel Time= 10.7 min Avg. Velocity= 0.23 fps, Avg. Travel Time= 25.7 min Peak Storage=427 cf @ 12.31 hrs Average Depth at Peak Storage= 0.02' Bank-Full Depth= 0.50' Flow Area= 25.8 sf, Capacity= 103.00 cfs 50.00' x 0.50' deep channel, n= 0.030 Short grass Side Slope Z-value= 3.07 Top Width= 53.00' Length= 350.0' Slope= 0.0171 T Inlet Invert= 220.00', Outlet Invert= 214.00' Reach EX-R: Overflow from Depression Hydrograph 1 ] I f [0 outflow 1 I i i f p 7.02 iE f o{Y',y) ,Area=36,f760 sf 1- I I E I i I ' I i I { QLvg.E Film De�p th=0.02' k E 1 M6X Ve1=;0.55;f0S III=0.030 E 45"0 L 1 �E 1.E�//,/�1 1 I I s Y 1 E F 3 1 1 I I ! 3 V!u. S=0.0171: 7, E Capi6city=1,03,.04 cfs I I 1 1 1 1 1 ! I 1 1 1 1 1 1 1 II I I I E I I E ! I I I I I I E 0 I { { I 1 I E 1 1 I I I k / 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type 11124-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 HydroCAD010.00-18 sln 01038 O 2016 HydroCAD Software Solutions LLC Page 9 Summary for Pond EX-P: Austin Field Depression Inflow Area = 36,760 A 10.02% Impervious, Inflow Depth > 1,26" for 2-YR event Inflow = 1.20 cfs 12.10 hrs, Volume= 3,870 cf Outflow = 1.02 cfs 12.16 hrs, Volume= 3,350 cf, Atten= 15%, Lag= 3.6 min Primary - 1.02 cfs @ 12.16 hrs, Volume= 3,350 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 220.23'@ 12.16 hrs Surf.Area= 8,413 sf Storage= 748 cf Plug-Flow detention time=88.8 min calculated for 3,350 cf(87% of inflow) Center-of-Mass det. time=28.0 min (880.1 - 852.1 ) Volume Invert Avail.Stora a Storage Description #l1 220.00' 4,561 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 220.00 225 0 0 220.10 1,635 93 93 220.20 6,690 416 509 220.30 12,150 942 1,451 220.40 16,065 1,411 2,862 220.50 17,915 1,699 4,561 Device Routing Invert Outlet Devices #1 Primary 220.20' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 46.00 65.00 115.00 140.00 150.00 Height(feet) 0.20 0.10 0.00 0.00 0.10 0.20 Primary OutFlow Max=1.00 cfs @ 12.16 hrs HW=220.23' (Free Discharge) t--1=Asymmetrical Weir(Weir Controls 1.00 cfs a@ 0.50 fps) 11625.09 - EX Type 1/124-hr 2-YR Rainfall=3.36" Prepares! by VHB Printed 2/21/2017 hydroCADO 10.00-18 s/n 01038 0 2016 HydroCAD Software Solutions LLC Page 10 Pond EX-P: Austin Field Depression Hydrograph 0 inflow 13 1.20 US ! I E l 3 1 € I I I Primary I I l;n f low Area=36,760 Sf c -ftak-Ele'v=220623` 1 q 5 -----3-- --I--�-- --`- 3 E 3 3 3 I ! f f 1 gI tci I ragIe'7 R Vy 1 !f 1 1 I 3 3 i f I E i € 1 7 I I I I f € ! ! I I 1 I I I } € LL I ! I t E = f 3 I I I I ] 1 3 I ! I # E ! 3 I 3 I I I # F 3 3 E E 1 I I f I I 1 I € I 3 I I ! I ! 3 3 1 I I I 1 I I 1 1 € f 3 i i 1 f i i I I I 1 i I 1 3 } I I 3 1 I I f I I { 1 0- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours). s e 11625.09 - EX Type 11124-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 11 droCAD® 10.00-18 sin 01038 ©2016 H droCAD Software Solutions LLC Page 11 Summary for Link DP-1: Site Total Inflow Area = 425,125 sf, 29.90% Impervious, Inflow Depth a 1.57" for 2-YR event Inflow - 14.56 cfs @ 12.13 hrs, Volume= 55,704 cf Primary - 14.56 cfs @ 12.13 hrs, Volume= 55,704 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1: Site Total Hydrograph - A I-- I I 1 1 r I 3 I 1 16- ; p Primary f I 1 1 1 1 1 14.56 tk I I 1 15' I'hflo ► Area= 25 1'2 -; -; 19 56 cfs .q � I 141 ! �ti,$.� 1 1 E I I i I I I 1 I 1 I 1 12- / 10 I VtiJ ': 97 E 3 I I F F ! 1 7 W , c / , 76y-; ..I.. .. ".11!..'.�ff`' _I-- , -.,--IE.-. -- 1 -- w, 2- E F 1 1 I I i� 0- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type Ili 24-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 HydroCAD@)10.00-18 s/n 01038 O 2016 HydroCAD Software Solutions LLC Page 12 Summary for Link DP-1A-1B: Rock Ridge Road/Elm Street Drainage System Inflow Area = 252,310 sf, 23.44% Impervious, Inflow Depth > 1.46" for 2-YR event Inflow - 8.14 cfs @ 12.12 hrs, Volume= 30,676 cf Primary - 8.14 cfs @ 12.12 hrs, Volume= 30,676 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-IA-1B: Rock Ridge Road/Elm Street Drainage System Hydrograph FM Inflw ! f I 1 ! ! 11 } € 1 O P '--�--1 '---'--�--1`-1 -P--�-- 8.14 tfs 1--�--1 '--J--'--L--1---1--1--L-- Maly a -InftoW Area=252,31 ! ! 1 I__ f I I ! ! E } I 1 I I I —i--�--! -— 7 C - € ! I I a 3 1 F V E F I t 3 ! 3 I I I I I ! 1 !5` I I I E—— i— I 3 i_ �_`I--`{_ l I —I— i IF —E—-11_T--r_ 3 ! ! I ! 2 ! € I I ! 1 t € E I ! 1 1 Q- 0 1 2 3 4 5 8 7 8 9 10 11 12 13 14 15 1& 17 18 19 20 21 22 23 24 Time (hours) I� I i 11626,09 - EX Type /it 24-hr 2-YR Rainfall=3.36" Prepared by VH B Printed 2/21/2017 HVdroCAD®10.00-18 s/n 01038 ©2016 HVdroCAD Software Solutions LLC Page 13 Summary for Link DP-ELM-1: Elm Street Basin Inflow Area = 172,815 sf, 39.34% Impervious, Inflow Depth > 1.74" for 2-YR event Inflow 6.80.cfs @ 12.16 hrs, Volume= 25,029 cf Primary 6.80 efs @ 12.16 hrs, Volume= 25,029 cf, Atten= 0%, Lag= 0,0 min i Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-ELM-1: Elm Street Basin Hydrograph Inflow a Primary - ' --l------I - -- I� I ..-°7 1nfl* AreaI=I72,01 -- l-- E1 3 7 3 I III j ! E I I 1 E I 1 I 3 ! f E 3 I I 3 I 1 _1..____ _____ _____ 1 1 I I E I f 1 I 1 1 1 1 f f E I 1 '-` 4 1 E [ E 0 I I 3 I I I k 3 3 1 I 7 I E f ,N i I I 3 1 3- 2 V h E I I I I € E 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type lli 24-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 s/n 01038 02016 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment 1: M-ELM-1 Runoff - 12.50 cfs c@ 12.15 hrs, Volume= 46,150 cf, Depth> 3.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR Rainfall=5.04" Area sf CN Description 67,980 98 Impervious 104,835 74 >75% Grass cover, Good, HSG C 172,815 83 Weighted Average 104,835 60.66% Pervious Area 67,980 39.34% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 1.1 125 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 80 0.1000 5.09 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.0 135 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 50 0.0150 2.49 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.8 260 0.0060 5.58 17.52 Pipe Channel, 24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50' n= 0.013 Concrete pipe, bends &connections 0.4 155 0.0060 7.01 34.42 Pipe Channel, 30.0" Round Area= 4.9 sf Perim= 7.9' r=0.63' n= 0.012 HDPE 0.9 675 0.0100 12.38 155.61 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 0.7 390 0.0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf" Perim= 12.6' r= 1.00' n= 0.012 HDPE 11.0 1,920 Total 3 11625.09 - EX Type 1l124-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 N droCAD®10,00-18 s/n 01038 02016 H droCAD Software Solutions LLC Page 15 5ubcatchment 1: M-ELM-1 Hydrograph 1 [ 1 F 14 i I E I 1 1 E I I 1 i 13- I k I 1 k I I 12.50 Cf5 I 3 3 1 I E I I 3 ! I 1 -Ty E E t I 1 I I k I I 12, ' @-III- 4 1 h'I E E t I 1 1 1 I k I 11 '10- R Rainfall*,5.64'---; 1 --1- T -r--r--r f --E- 1 r--r !"--i - �.. .. Y ., 10 = Runoff Areal-r y89 5 sf - Runoff Volum.er4.6,ISO cf - E I I I f I f I 3 3 I f I i E I 1 1 I I 3 Runoff-4eptO>3.2Q��--!1-- 7 I i y I 1 1 ! ' , d -Flow--�eogth-—,920--,--,k- u' 6. T T -------- I I m I I I E E f € I I ! € E 1 E ---t,c� 1.O I,1 OF -- -- --L f r--e---r--E---E- 5• ! E i 2- I .;,. �.....,_1---I---I--7--t-- r--F--,_--I--- ' 1 / E I I 3 E I I 1 I 0 0 1 2 3 4 5 S 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i 11625.09 - EX Type ]i124-hr 10-YR Rainfali=5.04" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 s/n 01038 ©2016_HydroCAD Software Solutions LLC Page 16 Summary for Subcatchment 1Ba: M-1A-1Ba Runoff -- 15.76 cfs @ 12.11 hrs, Volume= 52,525 cf, Depth> 2.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR Rainfall=5.04" Area (sf) CN Description 55,460 98 Impervious 160,100 74 >75% Grass cover, Good, HSG C 215,550 80 Weighted Average 160,100 74.28% Pervious Area 55,450- 25.72% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec) cfs 4.2 50 0.0400 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 3.6 430 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 7.8 480 Total Subcatchment 1 Ba; M-1A-1 Ba Hydrograph < F 7- I 3 i 1 I I 1 I i5 16: ! I �hh --,--;--,---,---- -TY�e ail �4 .,,: --._.. -.-------�------- ------- 15 . _._..I.. 1-'"t`_r _j__i_-rt". _... ,4= -10--YR_R'a--Afa11=:5..-04'I- • � I 1 I I 1 I E I I I E -�ii'_ I 3 1 1 I ! I 1 E 13: Runoff Area sf- 12 1 11= ff --_Volume# 52 525_cf E i 3__I__I_ - RunI I E i f ^ 1Q- I € 1 off-Depth>2.92--E--,- -- -- -- -- - I e PE]ow a LL O. E _f__ ...-9�� 7• Tf/� 1 7 E �M■I 3 I 4 I I E E E f I 1 1 I I 1 I 3 ■;{./sI e� �1+� } - �_-} I _,_I 1 S __[ _I -_i i 3 I __1__j-_1 ._!_. _ N w80 7--E--3 g_ V 2....T -r--r-----I--- 4- - i- -;--; - --- f � I 2; D. V' 0 1 2 3 4 _ 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time {hours} 1 11625.09 - EX Type If! 24-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 HydroCAD® 10.00-18 sln 01038 02016 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment 1 Bb: M-1 A-1 Bb Runoff = 2.49 cfs @ 12.09 hrs, Volume= 7,861 cf, Depth> 2.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.06 hrs Type III 24-hr 10-YR Rainfall=5.04" Area (so CN Description 3,685 98 Impervious 33,075 74 >75% Grass cover, Good, HSG C 36,760 76 Weighted Average 33,075 89.98% Pervious Area 3,685 10.02% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft>sec) (cfs 5.0 Direct Entry, Minimum Tc 5.0 0 Total, Increased to minimum Te= 6.0 min Subcatchment 1 Bb: M-1A-1 Bb Hydrograph p Runoff III I E I I 1.49 d, Type 'III :'24-h E I I 1 1 1 I I I E 3 I I I I I I 1 'Il0-YY Rainf�all=5:04" 2—Runoff Area=36,760 sf 3 3 t I f 1 f I ! E I I ! ! ! I I Runoff 'Vo;lu�ne=7; 816'l cf � ! 1 � Runo! ff bepth>2.57" I I 3 f E Tc=6.0 t� i n LL i E E I 3 IE f E 1 I I [ ! 1 3 I 1 I ! I ! I ! 1 3 1 I ! I E 3 I I 3 ! E I I I f ! I E 3 I I 3 1 k f I I I I 1 I E 3 I k I 3 1 k { 1 ! I 1 I I E I 1 3 E E I 3 1 I I 1 ! I I I ! I ! I 3 I U- 0 1 2 3 4 5 S 7 8 9 10 11 12 13 14 15 1S 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type /it 24-hr 10-YR Rainfaii=5.04" Prepared by VHB Printed 2/21/2017 y ro_. 0 0.00-98 sln 01038 02016 FlyclroCAD Software Solutions LLC Page 18 Summary for Reach EX-R: Overflow from Depression Inflow Area = 36,760 sf, 10.02% Impervious, Inflow Depth > 2.39" for 10-YR event Inflow = 2.28 cfs @ 12.13 hrs, Volume= 7,334 cf Outflow = 1.91 cfs @ 12.32 hrs, Volume= 7,259 cf, Atten= 16%, Lag= 11.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 0.84 fps, Min. Travel Time= 7.0 min Avg. Velocity= 0.27 fps, Avg.Travel Time= 21.7 min Peak Storage= 813 cf @ 12.20 hrs Average Depth at Peak Storage= 0.05' Bank-Full Depth= 0.50' Flow Area=25.8 sf, Capacity= 103.00 cfs 50.00' x 0.50' deep channel, n= 0.030 Short grass Side Slope Z-value= 3.0 T Top Width= 53.00' Length= 350.0' Slope=0.0171 7' Inlet Invert= 220.00', Outlet Invert= 214.00' Reach EX-R: Overflow from Depression Hydrograph ! I f I I 3 1 I 111 inflow 1 E E ' I 3 • f F , I ; 3 E Q outflow 10fWv 4re0=36 760 sf; t E I I ! ! ! I ! 3 � �i E 3 I I ! ! 3 ! 3 /r Y yg ,Flow Depth=o. '� I I [ i i E 3 , Ix Ve1= If I f Fla ;0.$41 I I I I I 3 1 ! 1 k t I f I I 11�=0.030 i I 1 3 I 3 I I I 1 I I I I LE yE =��10 s VG+,� 0 I 3 3 I I I I 3 I I 1 1 i U. 5-0.01 ■ 11 ,l,3 ! E I E"' 1 I I I I - I 3 1- Capacity;1;03.06 cfs I I E I I I I ! I I E I I i I I 1 I 3 ] 1 I I 1 F 3 ) 0 1 2 3 4 S 6 7 $ 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) P i 11625.09 - EX Type /it 24-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 HydroCA©® 10.00-18 s/n 01038 U 2016 HydroCAD Software Solutions L.LC Page 19 Summary for Pond EX-P: Austin Field Depression i Inflow Area = 36,760 sf, 10.02% Impervious, Inflow Depth > 2.57" for 10-YR event Inflow 2.49 cfs @ 12.09 hrs, Volume= 7,861 cf Outflow = 2.28 cfs @ 12.13 hrs, Volume= 7,334 cf, Atten= 8%, L.ag= 2.2 min Primary = 2.28 cfs @ 12.13 hrs, Volume= 7,334 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 220.25'@ 12.13 hrs Surf.Area= 9,519 sf Storage= 929 cf Plug-Flow detention time=51.7 min calculated for 7,318 cf(93% of inflow) Center-of-Mass det. time= 17.3 min (848.7 - 831.4 ) Volume Invert Avail.Stora e Storage Description #1 220.00' 4,561 cf Custom Stage Data (Prismatic)-isted below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 220.00 225 0 0 220.10 1,635 93 93 220.20 6,690 416 509 220.30 12,150 942 1,451 220.40 16,065 1,411 2,862 220.50 17,915 1,699 4,561 Device Routing Invert Outlet Devices #1 Primary 220.20' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 46.00 65.00 115.00 140.00 150.00 Height(feet) 0.20 0.10 0.00 0.00 0.10 0.20 Primary OutFlow Max=2.23 cfs @ 12.13 hrs HW=220.25' (Free Discharge) t-1=Asymmetrical Weir(Weir Controls 2.23 cfs @ 0.60 fps) i i 11625.09 - EX Type 11124-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2121/2017 HydroCAD®10.00-18 s/n 01038 ©2016 HydroCAD Software Solutions LLC Page 20 Pond EX-P: Austin Field Depression Hydrograph I f I I 1 I I E I E € a inflow 1 2.49 ds p Primary I i 1 1 I I € J I ! I E r { I I I 1 1 1 E I ! 3 E 4 [ Infilow Area=36,7;60 S;f . I I 3 I f 1 E z .. � 1 �r e'atle'v-22a.2 2 914 5-; -... ! f 1 3 E c ��orag€ e-�I E _ E � I I E i J d �•�� 1 E F 1 E i I I U. 1 3 3 3 1 I I I I I f { { I I 3 1 I 1 i I ! 3 ! I I I ! E I I f I I I I } 0 1 2 3 4 5 6 7 8 9 10 1i 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 1 i 11625.09 - EX Type Ill 24-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 ; HydroCAD010.00-18 sin 01038 02016 HydroCAC7 Software Solutions LLC Page 21, Summary for Link DP-1: Site Total Inflow Area = 1425,125 sf, 29.90% Impervious, Inflow Depth > 2.99" for 10-YR event Inflow = 28.24 cfs @ 12.13 hrs, Volume= 105,935 cf Primary = 28.24 cfs @ 12.13 hrs, Volume= 105,935 cf, Atten= 0%, Lag= 0.0 min j Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1: Site Total 1 Hydrograph / I. / I ��OW 3I Prima ry 30 ---4 - 12 1 28- -Ioflorv�-Area=425, 28.24- -- --, I 1 I I 3 E I I 1 I I I 1 1 1 I F --1, I--1 -----1-_.-1--I .. lF .,r--I-- -I-- -- 26. / I F i 24- I 1 1 E 1 I 1 I 1 I F 1 I 22- ! h 20- I [8' i6 I 3 I 3 1 € I I I F I I I 1 E 1 E I I 1 I I i I r—y 14- [ --_-�__--_L--__ J - 12: --- ---------- iQ' I I F I I / 6 I 3 E 1 E ! I I I I 1 I i i I E I I 1 I I i I I i I I I .. .....I... .. .. _.____ 4- 2- 0� 0 1 2 3 4 5 8 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i i I I 11625.09 - EX Type 11124-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2121/2017 HydroCAD(D10.00-18 sin©1038 0 2016_HydroCAD Software Solutions LLC Page 22 Summary for Link DP-IA-1B: Rock Ridge Road/Elm Street Drainage System Inflow Area = 252,310 sf, 23.44% Impervious, Inflow Depth > 2.84" for 10-YR event Inflow = 16.43 cfs @ 12.12 hrs, Volume= 59,784 cf Primary = 16.43 cfs @ 12.12 hrs, Volume= 59,784 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0,00-24.00 hrs, dt= 0.05 hrs Link DP-1A-1B: Rock Ridge Road/Elm Street Drainage System Hydrograph I E I l I__ __:-..f_-I_.. E i I 3 3 k E I ' 3 �.:.,. ul I i I I 3 I f I I Fs i7fi 16. 18A3 cis 1 p h18ry • -__ ,--- -- _- ,1[7 •� -C f�o�►-Area=�5',31- -fB.43ds -.;-----------:-----;-----;--,- [6, • E 3 i i 15- • 1 I I i I 3 3 f r- T r -1 - I fE I -F i--r 14. 1 3 I i i E 13; 1 i I t E 1 12 3 3 I I 1 I I i E I i -- 11- f 3 I i I i LL S. 7: j- , • ---E--y--i-`r--I--7--i--Y..-i-..'3- :°"�.>.y - .,,,..._-3--'--r I __y__r___-- I 4 E 1 I I I 1 I I f E 1 3 I 1 1 i 2_ 9: o 1 2 3 4 5 6 7 8 9 10 i1 12 13 14 15 16 V 18 19 20 21 22 23 24 Time (hours) EI I 11625.09 - EX Type 1i124-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 sln 01038 O 2016 HydroCAD Software Solutions LLC Page 23 Summary for Link DP-ELM-1: Elm Street Basin Inflow Area = 172,815 sf, 39.34% Impervious, Inflow Depth > 3.20" for 10-YR event Inflow 12.50 cfs @ 12.15 hrs, Volume= 46,150 cf Primary = 12.50 cfs 12.15 hrs, Volume= 46,150 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0,00-24.00 hrs, dt= 0.05 hrs Link DP-ELM-1: Elm Street Basin Hydrograph I .1 --�—— Inflow 19 13 Primary 13 �°°5l 'flo --Are -j72;81- tziw 12 '.. 1 I ( 3 I I I 1 1 I ! f I 1 3 f I 1 I I I I I I f E E • ! i � i F i 10' 9m I 3 I I 1 I I I { ! l 3 1 I 3 1 ! I ...I.,.. ...,_.. ....... .. ... ..._., _ ! I -- E p E r I a ! I I I I ! ! ! W C --i--l---f--r--{-- --r--r--I---I "; -1 i --r .., ..� ..4 V f { I { f I I I 3 I 1 E I I{ 4 i E E I I I I E 1 I 1 1__*___€__!__! __!__ E .....I„ _,,,1.,. „„_E - _ 1 I I -1-- 1 _I - I _ I_ 2, l t E ! E € I 3 k I 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type /H 24-hr 25-YR Rainfali=5.76" Prepared by VHB Printed 2/21/2017 HydroCAD® 10.00-18 s/n 01038 ©2016. Hydro CAD Software Solutions LLC Pape 24 Summary for Subcatchment 1: M-ELM-1 Runoff = 15.00 cfs @ 12.15 hrs, Volume= 55,625 cf, Depth> 3.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt=0.05 hrs Type III 24-hr 25-YR Rainfall=5.76" Area (sf) CN Description 67,980 98 Impervious 104,835 74 >75% Grass cover, Good, HSG C 172,815 83 Weighted Average 104,835 60.66% Pervious Area 67,980 39.34% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 1.1 125 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 80 0.1000 5.09 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.0 135 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 50 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 260 0.0060 5.58 17.52 Pipe Channel, 24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50' n= 0.013 Concrete pipe, bends & connections 0.4 155 0.0060 7.01 34.42 Pipe Channel, 30.0" Round Area=4.9 sf Perim= 7.9' r= 0.63' n= 0.012 HDPE 0.9 675 0.0100 12.38 155.61 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 0.7 390 0,0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 11.0 1,920 Total i i 11626.09 - EX Type/1/ 24-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 H droCAD@ 10.00-18 sfn 01038 02016 H droCAD Software Solutions LLC Pacie 25 Subcatchment 1: M-ELM-1 Hydrograph � I E I ! t I I i E 1 I CI Runo€f 16.00 ds : � 15 rtYpe.. I1 4yhri-- --�-----1 j � -�-J---1 -J 1--t--1---I-- 1 , I 1 Y-- 1 I 1 1 I 1 ' E --- E I !13' ' 25- fa311=;5.7fi' 1 13, 1 I ! �--Y--r--r--r--I-- _ ; 12; _Runoff_Area-ll72 8 _5sf , L-- --;----- --E__.;....._ ....11.. .. I f ! { I ' ! I E 1 I I ! ! I f ! E I I I 11 ---1-- -- Runoff Volume-55-625 cf 10- ! E I I € E € I I 1 I I I I € _ __ r{ 3 __ __r_ I I__ __ E. 3__i 9 Runoff Deptf � .8 -3 -E- 1 _I ._-1 4 • I F 1 1 € I V I I I 3 1 I E _ -Flowe6gth=1,920' LL 7-' C=I `_ V {1 n €I I I I 1 I 1 k ( I 1 _ __3 _!-_E___I E_ _ E __`___ _E _ _ 4- I 1I I I f ! E 3 I I I E E E I 3_ ' ! I E I I I f I E I I I I I k k I € € 2 --`I---'--"I--J-- --L- L -E- -I- f I I I E 1 I I I I 1 E f ! { ! I D• D 1 2 3 4 B 7 8 9 10 11 12 13 14 15 18 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type ill 24-hr 25-YR Rainfafi=5.76" Prepared by VHB Printed 2/21/2017 Hydr®CAD® 10.00-18 sfn 01038 02016 HydroCAD Software Solutions LLC Page 26 Summary for Subcatchment 1 Ba: M-1 A-1 Ba Runoff = 19.15 cfs @ 12.11 hrs, Volume= 63,968 cf, Depth> 3.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR Rainfall=5.76" Area (sf) CN Description 55,450 98 Impervious 160,100 _-74 >75% Grass cover, Good, HSG C 215,550 80 Weighted Average 160,100 74.28% Pervious Area 55,450 25.72% Impervious Area Te Length Slope Velocity Capacity Description (min) (feet) (ftlft) (ft/sec) (cfs) 4.2 50 0.0400 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 3.6 430 0.0150 1.97 Shallow Concentrates! Flow, Unpaved Kv= 16.1 fps 7.8 480 Total Subcatchment 1Ba: M-1A-1Ba Hydrograph 21= --`---€-- 1..... - --i-----L--'---'- ..3._. .t.... E f I I 1 I t 1 I I E 203 19.35 Ns 3 I i I 1 r f I t € E € I I I 19' Yy 'e fl1 4 hlr --t i I i 17 25w_ k Ri6611=5.75'� - € 15.' _Rundf_M_66 29.5,550-Sf_ ; I 14 -- -- 73_ Runoff VO1urhe 63 968'�cf I 1 --II-- __r _7_.._,...__.r ^ - , k I I I 3 I I 1 I t 3 i : 12 Runoff-Depth>3.56 -,-- ; -;--1 ... _. . -- --T--.--r -- 11: - ----'- - -- -------- ! �F E F 0 10- / IOW .epgth=4$0-�!_-- I ` i I 1 I E I --CN=V_O—}--;—_3 z. E [ I I ��I-- -� I�f�I I I . I E • I I ! 1 I I I i I I i 3 1 I I 3 1 I I 1- �- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i 11625.09 - EX Type llf 24-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 HydroCAD010.00-18 sln 01038 ©2016 HydroCAD Software Solutions LLC Page 27 Summary for Subcatchment 1 Bb: M-1 A-1 Bb Runoff = 3.08 cfs 12.09 hrs, Volume= 9,714 cf. Depth> 3.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR Rainfall=5.76" Area (sf) CN Description 3,685 98 Impervious 33,075 74 >75% Grass cover, Good, HSG C 36,760 76 Weighted Average 33,075 89.98% Pervious Area 3,685 10.02% impervious Area Tc Length Slope Velocity Capacity Description min feet fE/ft) (ft/sec) (cfs 5.0 Direct Entry, Minimum Tc 5.0 0 Total, Increased to minimum Tc= 6.0 min Subcatchment 1 Bb: M-1 A-1 Bb Hydrograph f E 1 1 E ! r! 3.00 al; 3 {JyN/{ eii Lwn 1 25-YR Rainfall-r517i6" i I I It E Runoff ArOa=36 E I I,760 sf k I I ! 1 I E E I f ! -Ruh E I ' Runoff V, 6julmie=0,7;14; cf I 2- k Runof I f I Depth 1 I >3A I I 7I I 1 1 ! E I E f " 3 f y>° Tc-6a0 C 1 E ni i�I =7 GI_N__ l � - _ 1 I I 1 1 I I I I I E 1 I I I I I 3 i I I I I k E I I I I 1 1 1 I I 1 ! I f r E I 3 I E I I I I I I I 1 ! 3 ! E ! I 1 I I I I 0- , 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type /Y 24-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 N droCADO 10.00-18 sln 01038 O 2016 H drOCAD Software Solutions LLC Page 28 Summary for Reach EX-R: Overflow from Depression Inflow Area = 36,760 sf, 10.02% Impervious, Inflow Depth > 3.00" for 25-YR event Inflow = 2.84 cfs @ 12.13 hrs, Volume= 9,184 cf Outflow = 2.45 cfs @ 12.30 hrs, Volume= 9,097 cf, Atten= 14%, Lag= 10.3 min Routing by Stor-Ind+Trans method, Time Span=0,00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 0.92 fps, Min. Travel Time=6.4 min Avg. Velocity= 0.29 fps, Avg.Travel Time= 20.3 min Peak Storage= 938 cf @ 12.19 hrs Average Depth at Peak Storage= 0.05' Bank-Full Depth= 0.50' Flow Area= 25.8 sf, Capacity= 103.00 cfs 50.00' x 0.50' deep channel, n= 0.030 Short grass Side Slope Z-value= 3.0 'P Top Width= 53.00' Length= 350.0' Slope= 0.0171 7 ' Inlet Invert=220.00', Outlet Invert= 214.00' Reach EX-R: Overflow from Depression Hydrograph 3 i I 1 3 El Inflow aOLIfflOw Inflow ,4rea-36,;760 sf: 3 I ] 3 I I 1 I I I [ Avg..Flow Depth=o. 2.45 fs 3 I I ! 1 -MaX V6i l=0.0Z fpa-'- 3 € 1 I I I I 2- = Y 0 030 I I I 3 1 3 I 1 E E I I _ I !r�I =3Y10■0 i E I I i ; R I I I I L f [E I I I 1 i E F i } I E � 1 1 �` ! ( F I { V >� S=0.0171 J__ i __L-_I .J... _. / Capacity=103;.0b 6% i / I 1 E I I I I 1 € I I I I 1 I I I [ I I I h E I I 1 ! I I 3 1 I I f I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 Time (hours) ?Ei I i 11625.09 - EX Type /Ii 24-hr 25-YR Rainfall=5.76" Prepared by VH B Printed 2/21/2017 H droCAD®10.00-18 s1n 01038 02016 H droCAD Software Solutions LLC Page 29 Summary for Pond EX-P: Austin Field Depression Inflow Area = 36,760 sf, 10.02% Impervious, Inflow Depth a 3.17" for 25-YR event Inflow = 3.08 cfs @ 12.09 hrs, Volume= 9,714 of Outflow = 2.84 cfs @ 12.13 hrs, Volume= 9,184 of, Atten= 8%, Lag= 2.0 min Primary = 2.84 cfs @ 12.13 hrs, Volume= 9,184 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev=220.26'@ 12.13 hrs Surf.Area= 9,917 sf Storage= 1,000 cf Plug-Flow detention time=44.9 min calculated for 9,184 of(95% of inflow) Center-of-Mass det. time= 15.7 min ( 841.0 -825.3 ) i Volume Invert Avaii.Stora e Storage Description #1 220,00' 4,561 of Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 220.00 225 0 0 220.10 1,635 93 93 220.20 6,690 416 509 220.30 12,150 942 1,451 220.40 16,065 1,411 2,862 220.50 17,915 1,699 4,561 Device Routing Invert Outlet Devices #1 Primary 220.20' Asymmetrical Weir, C=3.27 Offset (feet) 0.00 46.00 65.00 115.00 140.00 150.00 Height(feet) 0.20 0.10 0.00 0.00 0.10 0.20 Primary OutFlow Max=2.77 cfs @ 12.13 hrs HW=220.26' (Free Discharge) t1=Asymmetrical Weir(Weir Controls 2.77 cfs @ 0.63 fps) 11625.09 - EX Type 111 24-hr 25-YR Rainfall=5.76° Prepared by VHB Printed 2/21/2017 HydroCAD® 10.00-18 s/n 01038 ©2016 HydroCAD„Software Solutions LLC Page 30 Pond EX-P: Austin Field Depression I I"Ograph flow E ! 3 1 i f f I � 1 3 I I i i �� _+ 1 f E I 3 [ I { $.6BC49 1 i I I i i I E E 0 Primary ��n �� ow A e =-36,7f 0 sfi E Peak Elev=220�2 EOd�' i . V I M �. 1 _ ".. cam" __ 1{ fly. 2 ( I tL ! I 1 I f I 3 I € I I ! I 1 I 1 ! 1 I I 3 I I I I f 1 1 1 I I E ! I I I I 1 1 I k I { 1 I I 1 3 I I I 3 3 i i I I I I E 1 1 t I E ! I I 1 I I 3 I I € 1 I I E E I I ! I I I I E a- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) E i 11625.09 - EX Type fll 24-hr 25-YR Rainfali=5.76" Prepared by VHB Printed 2/21/2017 H droCAD® 10.00-18 sln 01038 Q 2016 H droCAD Software Solutions LLC Page 31 Summary for Link DP-1: Site Total Inflow Area = 425,125 sf, 29.90% Impervious, Inflow Depth a 3.63" for 25-YR event Inflow — 34.32 cfs @ 12.13 hrs, Volume= 128,690 cf Primary - 34.32 cfs c@ 12.13 hrs, Volume= 128,690 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1: Site Total Hydrograph U Prima ry 36= -Inforjv Area;=425,1;2 3432tis 34= i ——--—,—----r-- 32- 30- I I. I 28; 26: 1 1 I I I 1 1 I ! 1 I ' .. I T I F 24 y 22: -�-- I i-- i -I__ -_ I --1 20. 1 - 6- I ! _ 3 14. ! I F 1 ! I i i :. t ! I I '-%'..�: I , I I I f I 3 --- -i-- - r ;:... 12- -J-- --L--i-- --F--L--I- --I----- 1 i : 4. I I 3 I / 0 0 1 2 3 4 5 5 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type /H 24-hr 25-YR Rainfali=5.76" Prepared by VHB Printed 2/21/2017 Y Solutions LLC H droCRD�1.0,00-18 sIn 01038 e0 2016 HydroCAD Softwarelu,S, ,page 32 Summary for Link DP-IA-1B: Rock Ridge Road/Elm Street Drainage System Inflow Area = 252,310 sf, 23.44% Impervious, Inflow Depth > 3.47" for 25-YR event Inflow = 20.15 cfs @ 12.12 hrs, Volume= 73,064 cf Primary = 20.15 cfs @ 12.12 hrs, Volume= 73,064 cf, Atten=0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1A-1B: Rock Ridge Road/Elm Street Drainage System Hydrograph 1 3 3 f 3 E 1 I 1 I El InHOW 113--_ kF€------I'I ----�.,-_.--.,�-- �-,-- ,-�--,- --,'----;.;-._-..�1--- - Primary 21 20.,s� 20. _- _J--1--L-- ,e i E 1 i I f I —1 i _ E E k 1 _ ___ _ —E — I �131 I , 12_ —E }� / r r 6. _- r-—_!_—J—_..1 k.__L_�__� ' I..__1-• .tea-% _I__�__J__3_-.-. e i I_ [ I I !__4-- 4 _. —E——1— -———I——I 2- 1- - 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 5 1 E 11625.09 - EX Type 11124-hr 25-YR Rainfall=5,76" Prepared by VHB Printed 2/21/2017 E H droCAD®10.00-18 sln 01038 ©2016 H droCAD Software Solutions LLC Page 33 Summary for Link DP-ELM-1: Elm Street Basin Inflow Area = 172,815 sf, 39.34% Impervious, Inflow Depth > 3.86" for 25-YR event Inflow — 15.00 cfs c@ 12.15 hrs, Volume= 55,625 cf Primary — 15.00 cfs @ 12.15 hrs, Volume= 55,625 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0,00-24.00 hrs, dt= 0.05 hrs Link DP-ELM-1: Elm Street Basin Hydrograph ®Inflow i ry ,,,i1 �s oo ers crs ,- ! , -r I r ! ,- ! -- me 16- ! 0 Prima 1 I t I I ! 1 f - F t 5 nf1O*-ArOz(= 72y811 -i-- --� 15- ' 14 I J J.-_.i I.. F ! -E-- I I -1__ F I I ! I 3 I I 1 F f I I E I ! I ! E I f I ! 11 E 10- I I __. -- ---- - I 3 I I E f ! € I I I E I tL 7- 3 I ! ! I I I 1 I E 1 .s`�. ! 1 ! I € I A 1 3 3 -3 _-I ___- 1 __---!---i 1 I I I �I _f__ 1__I I I ^t 3- I I I I F ! I I I E 1 I I I - ----y---f--Y--r-7----- --r- - - --r--I---s--1 --t - —--i--'I'- . 1 0 , 0 1 2 3 4 5 8 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type Ill 24-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 s/n 01038 ©2016 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment 1: M-ELM-1 Runoff - 17.23 cfs c@ 12.15 hrs, Volume= 64,180 cf, Depth> 4.46" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR Rainfall=6.40" Area (sf) CN Description 67,980 98 Impervious T 104,835 74 >75% Grass cover, Good, HSG C 172,815 83 Weighted Average 104,835 60.66% Pervious Area 67,980 39.34% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 1.1 125 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 80 0.1000 5.09 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.0 135 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 50 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 260 0.0060 5.58 17.52 Pipe Channel, 24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50' n= 0.013 Concrete pipe, bends & connections 0.4 155 0.0060 7.01 34.42 Pipe Channel, 30.0" Round Area=4.9 sf Perim= 7.9' r= 0.63' n= 0.012 HDPE 0.9 675 0.0100 12.38 155.61 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 0.7 390 0.0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 11.0 1,920 Total i 1 11625.09 - EX Type Ill 24-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 212112M H droCAD®10.00-18 sin 01038 ©2016 I i droCAD Software Solutions LLC Page 35 Subcatchment 1: M-ELM-1 Hydrograph I ' F 1 37.23 efg ___°___I__ E__-__-_.. • � E I I f { { 1 f I F I I € I 16_ ,OBOE-YR-kainfallIF'4011 _. . .. _ --- 1g - - 1 - I - I 14: Runoff-Area 1172 815 s# ; ;, .,- -;--;- --- 13' j 12 Ruho_ff_Vol_ulmeT.64J8,8 cf 11' Runoff-Deofli>4.4G�� -;-- ---- I I 1 9 I I �epgth-'1-928 ! 0 9: { _F-Cow.. _ - u --- 7: _________.._.. I� F I I I E t I E I 1 L... .., i I E ! . r /x� f 3 ! 3 ! f f I 6= ' .. �'�V _j__E__E .-3..,...,.i, .._.___I_ ; _ f t I 1 ( I 1 1 1 -- - . ____ E I 1 ----E. .,'. .f 3 I 1 4� • / -__I__..E I I -i--€--F--I--..f.., ....,.I- I ,� j--�--I_..�'_ �. .I�.. 1 E ! f f f I I 2"w _-_--I--- 1 0 1 2 3 4 5 fi 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23 24 Time (hours) I j 11625.09 - EX Type 11124-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 HydroCA0010,00-18 sin 01038 02016 ions LLC ydraCAD Software Solt Pape 36 „y ,., Summary for Subcatchment 1 Ba: M-1A-1 Ba Runoff - 22.19 cfs @ 12.11 hrs, Volume= 74,352 cf, Depth> 4.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Spam 0.00-24.00 hrs, dt= 0.05 hrs Type Ill 24-hr 100-YR Rainfall=6.40" Area (sf) CN Description,,, , 56,450 98 Impervious 60,100 74 >75% Grass cover, Good HSG C 215,550 80 Weighted Average 160,100 74.28% Pervious Area 55,450 26.72% Impervious Area Te Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.0400 0.20 Sheet Fla Grass: Short n= 0.150 P2= 3.32" 3.6 430 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16,1 fps,.::::::::,, 7.8 480 Total Subcatchment 1 Ba: M-1A-1 Ba Hydrograph I I -I----A-_.1,._.1__1__1___E_..._E..,- I- I I I 3 I { € E 1 { € E I f I { I f I 1 I 24'. --l---1,--- ---- ClRunaff 23`. --€-- .l,-....-1_- --i-...1..-- --'--J 22A0d:I 22 a� 100,=Yt I �Infi'�I1-64Q ---- '21 13 " L__i ----- -- ..-..L L--'---'--.2 . - .:_. 1 -r E __- 19- Runoff Area-215;550.s#. .. . :,_-- _'.....___- --- - -- --3--1--1c7c r 3 ! I I I1 I I I } E ! ! I 3 Runoff-Volurhe-74'352-c ^ 13 K h off_ -Qp th>4r14" II­.. _�-- --r--IL - � ..e.n 1■p�■ 10 94 �, _ L�_I_ _.. ...-ii' l..D__�__�.. .,r-_E___I___I ... _L__�_..1.,.� -A--.-... 7, _ .. _ .L_-E_ k_�-,I.....� '' :;l,.^_L..._L 1_ -- 5-'r 3 ` 1 i t ----- 3 f 1 { 1 I I 14 0= MEW 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i 11625.09 - EX Type !If 24-hr 100-YR Ra€nfalf=6,40" Prepared by VHB Printed 2/21/2017 i HydroCAD® 1Q.00-18 sln 01038 ©2016 HydroCAD Software Solutions LLC_ Page 37 Summary for Subcatchment 1Bb: M-1A-1Bb i Runoff = 3.61 cis @ 12.09 hrs, Volume= 11,409 cf, Depth> 3.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR Rainfall=6.40`I i Area sf CN Description * 3,685 98 Impervious 33,075 74 >75% Grass cover, Good, HSG C 36,760 76 Weighted Average 33,075 89.98% Pervious Area 3,685 10,02% Impervious Area To Length Slope Velocity Capacity Description (min) (feet) (ftlft) (fUsec) (cfs) 5.0 Direct Entry, Minimum Tc 5.0 0 Total, Increased to minimum To= 6.0 min Subcatchment 1 Bb: M-IA-1 Bb Hydrograph 4^ I f I I 1 I E t { I 1 I ! i I RUlIOff I I E E E I 3.84 Cos f I I 1 I i I Type III 24,'.hrT 3 i I l I I I I i i I I 1 I 1 3 [ 1 3 1 I [ ! I I 3 3 ! '1,00-YR-Rain al.l'=OAd.' ; - 3- � I 'Are' ! 3 I Runoff Are'aT36,76011sf E E 3 3 I I I h I I E I 1 I I Runoff Voiunhe?-11,409 Cf F f I I l t E I I I -Runo�-Qe 1 I I 1 f E I ft 7 ..1 v I p h i� � y 2-- ' Tc 6.0 i y N iO � 'r � ! CN=7S I 1 I E I E I f I I I I I E I 1 I E E E ! f 1 1 Q4 0 1 2 3 4 5 6 7 6 S 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type 11124-hr I00-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 H droCAD® 10.00-18 sln 01038 O 2016 H droCAD Software Solutions LLC Page 38 Summary for Reach EX-R: Overflow from Depression Inflow Area = 36,760 sf, 10.02% Impervious, Inflow Depth> 3.55" for 100-YR event Inflow = 3.37 cfs @ 12.12 hrs, Volume= 10,876 cf Outflow — 2.93 cfs @ 12.28 hrs, Volume= 10,779 cf, Atten= 13%, Lag= 9.5 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 0.98 fps, Min. Travel Time= 5.9 min Avg. Velocity= 0.30 fps, Avg.Travel Time= 19.3 min Peak Storage= 1,043 cf @ 12.18 hrs Average Depth at Peak Storage= 0.06' Bank-Full Depth= 0.50' Flow Area=25.8 sf, Capacity= 103.00 cfs 50.00' x 0.50' deep channel, n= 0.030 Short grass Side Slope Z-value= 3.0 T Top Width= 53.00' Length= 350.0' Slope= 0.0171 T Inlet Invert= 220.00', Outlet Invert= 214.00' Reach EX-R: Overflow from Depression Hydrograph I k 1 1 I I (1 M Infi�W I I 3 i i ! 3 E • f I I I E I 1 I I 0 OUISIOW 3.37 cfs E I I lhf oW Are2i=36,760 �f E f E AVg.€Florw Depth-.0.3 2.93 dStl k I f I 11OX I/el=f0.08;I fps i_h,=.0.030 i i ! 2- C d W=0.0 17 1 1OaOc 3 3 3 1 1 } 1 • � s k E 1 i I I 3 i f I ! I I I 1 1 1 1 E I I I i 0- o 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i I 11625.09 - EX Type 11124-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 H droCAD® 10.00-18 sin 01038 02016 H droCAD Software Solutions LLC Page 39 Summary for Pond EX-P: Austin Field Depression Inflow Area = 36,760 sf, 10.02% Impervious, Inflow Depth > 3.72" for 100-YR event Inflow - 3.61 cfs @ 12.09 hrs, Volume= 11,409 cf Outflow - 3.37 cfs @ 12.12 hrs, Volume= 10,876 cf, Atten= 7%, Lag= 1.9 min Primary = 3.37 cfs @ 12.12 hrs, Volume= 10,876 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 220.27'@ 12.12 hrs Surf.Area= 10,268 sf Storage= 1,065 cf Plug-Flow detention time=40.2 min calculated for 10,876 cf(95% of inflow) Center-of-Mass det. time= 14.6 min (835.3 - 820.7 } Volume Invert Avail.Storage Storage Description #1 220.00' 4,561 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store _(feet) (sq-ft) (cubic-feet) (cubic-feet) 220.00 225 0 0 220.10 1,635 93 93 220.20 6,690 416 509 220.30 12,150 942 1,451 220.40 16,065 1,411 2,862 220.50 17,915 1,699 4,561 Device Routing Invert Outlet Devices #1 Primary 220.20' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 46.00 65.00 115.00 140.00 150.00 Height(feet) 0.20 0.10 0.00 0.00 0.10 0.20 Primary OutFlow Max=3.27 cfs @ 12.12 hrs HW=220.26' (Free Discharge) t1=Asymmetrical Weir(Weir Controls 3.27 cfs @ 0.65 fps) 11625.09 - EX Type 11124-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 Fi droCAD®10.00-18 s/n 01038 02016 H droCAD Software Solutions LLC Page 40 Pond EX-P: Austin Field Depression Hydrograph A 1 F 13 inflow 4 E I ! f f I 3 # 1 i E I { I I E I E # Q Primary 3 E I f I '. ! 3 1 f 3.91 dS E ! f I � I i ! I S £ E ! I i Infliow area=36 760 sf l V .' 1 ! ! 1 I I 3 I 3 # Pe'al�- leer-220w27'- - r --f----- -_k--_-E----- i I E 1 1 3 3 I 1 torageT1 065 cf 3 3 3 1 1 I £ F I 1 1 ! I -...,..... -------- .,.--- - -I I - �VF }� 2` p 1 I I I I I I I 1 I E I E I 1 E i I I i LL ! I I ! I { ! 1 I f ! E I I E ! I I I E I I S f 1 ! 1 1 I ! I ! t t t 1f- 0 1 2 3 4 5 $ 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - EX Type Ill 24-hr 100-YR Rainfall=6.40 Prepared by VHB Printed 2/21/2017 Hydro ADO 10.00-18 sin 01038 ©2016 HydroCAD Software Solutions LLC Page.41 Summary for Link DP-1: Site Total Inflow Area = 425,125 sf, 29.90% Impervious, Inflow Depth > 4.21" for 100-YR event Inflow = 39.76 efs 12.13 hrs, Volume= 149,310 cf Primary = 39.76 cfs 12.13 hrs, Volume= 149,310 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0,00-24.00 hrs, dt= 0.05 hrs Link DP-1: Site Total Hydrograph 1 I E I I E I ! E � � E I E I I E { I Q I€3fiOW 44: -- I --, --�- L. .._! se.�aca9 42 3976 E„c,ts 2�51 40: O ' A0 I F 36- J I 32 ------- -- - -- - 3 I I I ! 1 I I I { - . 282 ' / / I I 3 I I 3 I I I I I ! 1 1 24 ---�--'- L-_1-_ p 20 . 1 / --1--r--r--r--I---1--r--r--I-- 'I ._E,..,....1... _,�.._r--r- -----;-----'--�-- W >, : L_-I__j-_i--L - 1 I 1 1 I I 1 I I ! 3 1 ! ! I 3 I I I 14' • I [ 1 I ! I 1 i I V.''- { I I I ' - --- 3 { I I I 12� - - / E E 1 8i I- --EE-----r--r----- `-: L 1. 4: 1 I I E I 3 I I f , 2-1 0= 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i 11625.09 - EX Type 1i124-hr 100-YR Rainfall=6.40° Prepared by VHB Printed 2/21/2017 H droCAD®10.00-18 sln 01038 02016 H droCAD Software Solutions LLC Page 42 Summary for Link DP-1A-1 B: Rock Ridge Road/Elm Street Drainage System Inflow Area = 252,310 sf, 23.44% impervious, Inflow Depth> 4.05" for 100-YR event Inflow = 23.48 cfs @ 12.11 hrs, Volume= 85,130 cf Primary = .23.48 cfs @ 12.11 hrs, Volume= 85,130 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1A-1B: Rock Ridge Road/Elm Street Drainage System Hydrograph I 3 ! £ 1 I I I I ! I I [ 1 1 f I f 1 IFF1fOW 1 1 ! I 1 I I I 23A8ds ! 1 1 I t t + E ! Q i'rimary 2-3.-4 9=cfa- s24 -1nf1o*-Are4-252; 22; 20 1 i 14 ---- [ i : �I_�y ��• { I 1 7 + I 1 I 3 I f 1 € # € -----�- 3 p 12: __I__�__i__r__t....--- W 3 t L'" � --i---f--T--�--I � '1...-T -i--I--1-- .:;_.: ..£..-� ! 7--�--I-..-,.. r--1---I--l_- E ! f € 1 I I I I I 1 I f I 1 I 1 i , �-- { I I I I E 47 o 1 2 3 4 5 B 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 1 i I I 11625.09 - EX Type 11124-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 H droCAD® 10.00-18 s1n 01038 ©2016 H droCAD Software Solutions LLC Page 43 Summary for Link DP-ELM-1: Elm Street Basin i Inflow Area = 172,816 sf, 39.34% Impervious, Inflow Depth > 4.46" for 100-YR event Inflow = 17.23 cfs @ 12.15 hrs, Volume= 64,180 cf Primary = 17.23 cfs @ 12.15 hrs, Volume= 64,180 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-ELM-1: Elm Street Basin Hydrograph l J I.,.._ 1 , ' - 131f1i1oW 19, . -�- - J !, a a... .. I ❑23cfs r I..., i- 1..., 1 L.., _ E _.. Cl Primary 1g IEnflo Area 72 81 ;723ag E 1 , 3 I f f € 3 17V W :_/y� , 1 f 14' __-__-__f________r__f_____ ____-__ 13 1 / i f 12= 114 IT �- 10. 3 --E---E-- --j--�--;--F--j--E-- , -I---,-----I ---- ----€ ---- --i-- . LL 4: / r 7, I___'__ _ ? _ c , 3 1 4 3T 2; F �I 0m 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 Time (hours) 10 `4 B M-E M-10 M-1 -10B DP-ELM-1 DP-1A-1B Elm Street B in :Rock idge Road/Elm te Drainage System DP 1 Site Total Subcai Reaeh on Lj� Routing Diagram for 11625.09-PR-Phase 3 Prepared by VHB, Printed 2/21/2017 HydroCADD 10.00-18 sln 01038 O 2016 HydroCAD Sofhvare Solutions LLC 11625.09 r PR - Phase 3 Prepared by VHB Printed 2/21/2017 HydroCAD® 10,00-18 sln 41038 ©2016 HydroGAD_Software Solutions LLC Pape 2 Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 226,110 74 >75% Grass cover, Good, HSG C (10, 10B) 62,465 98 Impervious, BLDG (10) 5,490 98 Impervious, BLDG Overhang (10) 131,060 98 Impervious, PVMT (10, 10B) 426,126 86 TOTAL AREA 11625.09 - PR - Phase 3 Prepared by VHB Printed 2/21/2017 HydroCAD@)10.00-18 s/n 01038 ©2016 HydroCAD Software Solutions LLC Page 3 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover 0 0 226,110 0 0 226,110 >75% Grass cover, Good 0 0 0 0 62,465 62,465 Impervious, BLDG 0 0 0 0 5,490 5,490 Impervious, BLDG Overhang 0 0 0 0 131,060 131,060 Impervious, PVMT 0 0 226,110 0 199,016 426,126 TOTAL AREA 11625.09 - PR - Phase 3 Type 11124-hr 2-YR Rainfall=3.36" Prepared by VH B Printed 2/21/2017 HydroCAD010.00-18 s/n 01038 02016 HydroCAD Software Solutions LLC Pace 4 Summary for Subcatchment 10: M-ELM-10 Runoff - 18.21 cfs @ 12.13 hrs, Volume= 63,835 cf, ❑epth> 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs E Type III 24-hr 2-YR Rainfall=3.36" Area (sf) CN Description 62,465 98 Impervious, BLDG 128,350 98 Impervious, PVMT 192,145 74 >75% Grass cover, Good, HSG C 5,490 98 Impervious, BLDG Overhang 388,450 86 Weighted Average 192,145 49.46% Pervious Area 196,305 50.54% Impervious Area Te Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 0.8 125 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.3 80 0.1000 5.09 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 90 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 35 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.1 20 0.0100 4.91 3.86 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 HDPE 0.6 350 0.0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 0.8 510 0.0070 10.36 130.20 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 9.1 1,260 Total 11625.09 - PR - Phase 3 Type 11124-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 Fi droCAD010.00-18 sin 01038 02016 H droCAD Software Solutions LLC Page 5 Subcatchment 10: M-ELM-10 Hydrograph I I I I f 1 i I 1 1 i 3 I I 20 --I--'--i--.i L--L 19: ' � � �-I� __...I --I-- -- --!--L--1---1---I- I-------'-- 18- T !e.111 4wFI h.rI!. 17: ZYkRanf6 IJL`_3_L 3_t_IfI_" 16 I 1 I F E I 14= -Runoff-Area-388,-450sf-,- ri - --1-- 3 --F---f--- f ` � I 3 I € 13 Ru off-Vollume-r63y835'-cf -�--I 1 t F 1 ! 3 12• I I i I E E I I I f I ! I } . � I I i ,�- floweh='l-E260'--- -- !L 9:- -....f.,.-._.L,,,_......._ 6 L 1..._-I---}--- i f h � I I i 3 i I ���.: E I I i 7 --[---E - _,}._ -.,.I__J__1 _L__L__L_J__J__1__1__1__L__I_......3_. . E E I I I i € I I I 1 •: h k I i I 1 I I I 1 , 4 3 --r--f---E--,---r--�.................._I--_7-- I f i E I 1 E i 0 0 1 2 3 4 5 S 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) I 11625.09 - PR - Phase 3 Type i1124-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 HydroCAD010,00-18 sin 01038 02016 HydroCAD Software Solutions LLC Palle 6 Summary for Subcatchment 10B: M-1A-10B Runoff = 1.11 cfs @ 12.12 hrs, Volume= 3,859 cf, Depth> 1.26" 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR Rainfall=3.36" Area sf CN Description i 2,710 98 Impervious, PVMT 33,965 74 >75% Grass cover, Good, HSG C 36,675 76 Weighted Average 33,965 92.61% Pervious Area 2,710 7.39% Impervious Area Tc Length Slope Velocity Capacity Description (miry) (feet) (ftlft) (ft/sec) (cfs) 3.8 50 0.0500 0.22 Sheet Flow, -- Grass; Short n= 0.150 P2= 3.32" 1.7 125 0.0060 1.25 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 360 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8,1 535 Total Subcatchment 10B: M-IA-10B Hydrograph Ty p el I 1 '24-h 3 3 ! E € I I f I I I I 1 2-YR Rainfall=3.36'" RI 1 I I u"' off Ar�aL-36E ,675 sf f ! ! ! I I 1 I 3 € E 1 I I k I I I Runoff Vo)uine'=$,8'59, c f E I t I I 1 I Ruinofl` bed th>9.26',' k F y � i MoW Ldngth'=535' LL f 1 3 ! 3 E I E f TCr8.�1 mMO 1 I f C N-7,6 E 1 I I 3 t E I k I ! i I 1 I 3 I 1 E I 1 - I [ ! E 1 1 3 I I { 3 E I 1 i �- 0 11 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - PR - Phase 3 Type 11124-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 sln 01038 ©2©16 HydroCAD Software Solutions LLC Page 7 Summary for Link DP-1. Site Total Inflow Area = 425,125 sf, 46.81% Impervious, Inflow Depth > 1.91" for 2-YR event Inflow = 19.31 cfs @ 12.13 hrs, Volume= 67,694 cf Primary = 19.31 cfs @ 12.13 hrs, Volume= 67,694 cf, Atten= 0%, Lag=0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1: Site Total Hydrograph 1 I E E i I I _€__-__—r_ — 3 ___ i _ In! ow I I I 1 I 1 I I i ' 21. -- [3 Prima 20 €9.31 !f rI } ry -- --1- ----- 1 - - I E -i_--- I I 1 1174 14, I -I--A--T- 11 -... 3 € E € I 3 i I - --E-- -__ 1 y� // I € i 3 ! I 1 E ar O 10: -'--J--1--L--'--J-- --E--'-_--l---.a..._ I -E 7--F--j-l---f--T--'--I--1-- / F / E t � 3 - -J- -€-- --I-_ -L- ' -J- -L- - -�- 2 1 0- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 Time (hours) 1 i i 'i. 11625.09 - PR - Phase 3 Type 11124-hr 2-YR Rainfall=3.36" Prepared by VHB Printed 2/21/2017 H droCAD®10.00-18 s/n 01038 ©2016 H droCAD Software Solutions LLC Page 8 Summary for Link DP-1A-1B: Rock Ridge Road/Elm Steet Drainage System Inflow Area = 36,675 A 7.39% Impervious, Inflow Depth > 1.26" for 2-YR event Inflow - 1.11 cfs c@ 12.12 hrs, Volume= 3,859 cf Primary - 1.11 cfs @ 12.12 hrs, Volume= 3,859 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1A-1 B: Rock Ridge Road/Elm Steet Drainage System Hydrograph 13�Inflow C1 Prima da 1 ! I 1 E ! E 3 f I ry i ! 1 I I E i i I I E E T7/cig I f E � i ! i ! fnf ow ke -36AT --'-- ' ' - -.--z - ---- i .. k f f f 3 I 1 f ! f E € I I 3 3 1 I 3 I I I 1 I t f f I 1 3 I I 3 I F f f E I I I I F f 1 i I 3 3 I 3 I F f I 1 I I I I 3 I k 1 I 3 3 I 1 I I 3 ! F E I ! I 3 € ! 1 3 I I LL - 0 4 5 6 7 8 9 i0 11 12 13 14 iS 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - PR - Phase 3 Type 11124-hr 2-YR Rainfall=3.36° Prepared by VHB Printed 2/21/2017 HydroCAD® 10"00-18 s/n 01038 ©2016 HydroCAD Software Solutions LLC Page 9 Summary for Link DP-ELM-1: Elm Street Basin Inflow Area = 388,450 sf, 50.54% Impervious, Inflow Depth > 1.97" for 2-YR event Inflow — 18.21 cfs @ 12.13 hrs, Volume= 63,835 of Primary — 18.21 cfs @ 12.13 hrs, Volume= 63,835 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-ELM-1: Elm Street Basin Hydrograph 3 i I 1 1 3 E I / I --I-_1__L_-I--J__1__L-_I_--I__J__L__L_J__1__L__[---'.__J__ n 24, ---�--�--+--�--I--�--+--�--I--�- ta.2tcts --1--�--�---�--1--�--s--�-----�--a-- 113Primary 19. 1 I I 1 3 I I f I F F E I r -Inflo Are' a,-_388A5 --I--�- 18 --I--y---:--r--r-----r--r--.--�--z-- 17'. ,• '3-`7"- f-_1_.._1.... _.I_..yl`'"'I-` '" `1`-`1 -4--r--�- --1"-T `-[`-1 - 16: / ! 3 7 I _....1-_. ( -,- 13' i 1 i I 1 i 12- I I I I 1 1 E / ,__7 __I__�___i__r__.I___i_____r__1___,__�__ ti I i I LL 9 / __. __._3.. 1....L ..1.._..,I.,,_1......I,._.,.i._..!-. :su' ._I_._J_..J _L !_J__.-I_-L / / i i� i �_•• F 6 F , 3- --I-- - 2 0= 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (flours) i li I I I 11625.09 - PR - Phase 3 Type 11124-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 HydroCAD010.00-18 sln 01038 ©2016 HydroCAD Software Solutions LLC Pace 10 Summary for Subcatchment 10: M-ELM-10 Runoff - 31.89 cfs @ 12.13 hrs, Volume= 113,287 cf, Depth> 3.50" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR Rainfall=5.04" Area sf CN Descri on 62,465 98 Impervious, BLDG 128,360 98 Impervious, PVMT 192,145 74 >75% Grass cover, Good, HSG C 5,490 98 Impervious, BLDG Overhang 388,460 86 Weighted Average 192,145 49.46% Pervious Area 196,305 50.54% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.5 50 0.0200 0.15 Sheet Flow, Grass; Short n= 0.150 P2= 3.32" 0.8 125 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.3 80 0.1000 5.09 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 90 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 35 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.1 20 0.0100 4.91 3.86 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 HDPE 0.6 350 0.0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00` n= 0.012 HDPE 0.8 510 0.0070 10.36 130.20 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00` n= 0.012 HDPE 9.1 1,260 Total 11625.09 - PR - Phase 3 Type IR 24-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 sfn 01038 ©2016 HydroCAD Software Solutions LLC Page-1.1_ Subcatchment 10: M-ELM-10 Hydrograph I 1 --! ! _ E E I I 1 I I 3 I i I 1 I f�U�Off 34 I I I f € I I -'-i-�-r-�---l--t--r--r--r--I---I- 91.89 ds I-r--r--r--f--�--y--�--r--r--r--r`- 32 f E ! ! f ! I I Ype_l1- 4- r -- �} I I �F i �;0=�(R Rainal =0A4 �,. 28: r I I I 1 f I 3 1 3l'- e �pE uNoff'Are 88 4�0-sf -------------- -`" E 26; R Af T TAT 1 1 1 ".�^. ! i I E E i i I 1 1 _ �, 3 I i I I i 3 I i I I ! I 3 I 24 -kunoff Vol6r a=118.. 87 c 22. I 20 �..€- 1-__f__7--t----_r- __I-----7_� -_ ------Y__r RUnof_f..Qepth>.�50�� 3 I E ry a 1 1 E E E E 1 I 1 I I �w 3 -Rlor A`er gth=1 260'- d a I : 1 I 1 L. Tc w,,,,A Min: __ ----- _- . 12. T--r--I--I--i---I--1 i ! I - ____r.__1___I__�__i__ F__rr.__I_ f I { E I 1 I 1__I __L__I___I___f___ __.___1___I___F__J__ E__L__L 4 f I 3 E ! I 1 I ! 3 3 I E [ E I I 2- ? 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Tlme (hours) i i I 11625.09 - PR - Phase 3 Type 11124-hr 10-YR Rainfall=5.04" Prepared by VH B Printed 2/21/2017 HydroCAD®10.00-18 s/n 01038 O 2016 HydroCAD Software Solutions LLC Pa4e 12 Summary for Subcatchment 1OB: M-1A-10B Runoff - 2.32 cfs @ 12.12 hrs, Volume= 7,839 of, Depth> 2.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs i Type III 24-hr 10-YR Rainfall=5.04" Area sf CN Description " 2,710 98 Impervious, PVMT 33,965 74 >75% Grass cover, Good, HSG C 36,675 76 Weighted Average 33,965 92.61% Pervious Area 2,710 7.39% Impervious Area To Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 3.8 50 0.0500 0.22 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 1.7 125 0.0060 1.26 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 360 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8.1 535 Total Subcatchment 10B: M-1A-1OB Hydrograph r 3 1 I I r ! F 232 C14 I ! I ! 3 1 �y�■�.Ar 124 1■y TyPV I^1 '^ ^�-h, 10=YR-Rainfallfi5.04"..k - -;---E--, I--,-- - ,--,-- 2` I I ! I I I Rulnoff ArbaL36,675 sf ! RuOoff VdjujnO=7�839 Cf I I I [ I 1 r 3 Ru noff D! E P h>i 6" Flow Len f h'=535' _ 1..- i TC=8A mid I I i \� 76 r r 1 1 1 1 i I I 0- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i 11625.09 - PR - Phase 3 Type ill 24-hr 10-YR Rainfall=5.04" Prepared by VHB Printed 2121/2017 HydroCAD®10.00-18 sln 01038 ©2016 HydroCAD Software Solutions LLC Page 13 Summary for Link DP-1: Site Total Inflow Area = 425,125 sf, 46.81% impervious, Inflow Depth > 3.42" for 10-YR event Inflow — 34.18 cfs @ 12.13 hrs, Volume= 121,127 of Primary = 34.18 cfs @ 12.13 hrs, Volume= 121,127 of, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1: Site Total Hydrograph I I I i I I I 3 y r I 1 Y r I t I 13 Inflow 38- ' I I I ; - _ aa.iscft -1-- -- --t-- --*-- -----1--� 0Pnma ryl 36- /J� 34. 34 -Infol' Ar/G'►' a- 25,12 I t 3 i 1 3 3 I I 32. ' � T 30: ——1— 1 3 E ! ! ! 3 f 3 i 28- 1 1 1 - ----1 I --E----- --r - -I---I-- -----I---S--F-----E-- --3 ------i---i-- 26= i ! 24' ——�— itiI 1 1 �p 22: 1 1_ ( E E —-- I ——� E---I— '——�— ..r 20. 1__ 1. 14 1 I 1 E f I 3 F 1 E f 3 12- ----[ E I I I I is qyy I I -�-�� I 1__-__E__J__1__L__I_ . f 4' ' 2'.' 0= 0 1 2 3 4 5 S 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 1 E 11625.09 - PR - Phase 3 Type I1124-hr 10-YR Rainfall=5.04" Prepared by VH B Printed 2/21/2017 I i droCAD@ 10.00-18 sin 01038 ©2016 N droCAD Software Solutions LLC Pacie 14 Summary for Link DP-1A-1 B: Rock Ridge Road/Elm Steet Drainage System Inflow Area = 36,675 sf, 7.39% Impervious, Inflow Depth > 2.56" for 10-YR event Inflow = 2.32 cfs @ 12.12 hrs, Volume= 7,839 cf Primary = 2.32 cfs @ 12.12 hrs, Volume= 7,839 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1A-1B: Rock Ridge Road/Elm Steet Drainage System Hydrograph i 1 F I I 3 3 E 1 I I i k I 1 I 1 I®ifE{IDW I i I I 3 I I 2s2 d$ I i 3 € I E I Q Pnma I I ■I iW oW Ai e . =36 67 2a2�8 { = I 3 I 1 1 i 1 I 1 3 3 1 I i 3 I I I 2 3 3 3 3 f I 1 ! 1 1 1 ! ! f I T. 1 I I 3 k 3 3 3 3 E I I 3 3 1 I 1 I 1 3 1 1 3 I I I 1 { 1 I ! ! 1 I I 3 3 3 f I I I 1 1 I ! 3 I I I 3 V i 3 3 3 f I 7 1 1 I I 3 E 3 3 3 3 E I I I 3 1 1 I 1 E 3 1 I 3 I I I 3 I I 0n. Q 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - PR - Phase 3 Type III 24-hr 90-YR Rainfall=5.04" Prepared by VHB Printed 2/21/2017 HydroCAD® 10,00-18 s/n 01038 ©2016 HydroCAD Software Solutions LLC Page 15 Summary for Link DP-ELM-1: Elm Street Basin Inflow Area = 388,450 sf, 50.54% Impervious, Inflow Depth > 3.50" for 10-YR event Inflow = 31.89 cfs @ 12.13 hrs, Volume= 113,287 of Primary = 31.89 cfs @ 12.13 hrs, Volume= 113,287 of, Atten=0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0,00-24.00 hrs,•dt= 0.05 hrs Link DP-ELM-1: Elm Street Basin Hydrograph I 1 E I I 1 I k i 1 k E i-----I---;--i--;--,---I--;--;--,---,-- --p-- .... , ; -;-- --;-- M Inflow I : 0 primary J _ ....1-... _!_.....7--[ --E---:--T--r--1---I-- 3�.$s CAS -1---I--J--�---I-.,._'.,.,.-1`-[' -k-``!---1-- 34' ,J I E : .". I I k. E I 1 i ! [ ! I 32, Iofjo* Area=388, 5 131.89 .__'_T__T --r-T--t--r--k---c-- --r--E---I- - '--,- - --r-- ri--r--k---E -,- 30, JJ -_,--y--T--Y--E- 2$- I E I 26' J 24 J- 22- J - yf20 I 14- F 1 I127 I I ! 1 1 f I I ! € I 1 t T__T f I 1- , 1 T 10, I --T--r---- -1--T--r--i--,--T-- .-r_-!---�--T--r--I--�--�-- 6; J , 4 - f I 2_ 0= 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Tfine (hours) E i I 11625.09 - PR - Phase 3 Type 11124-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 HydroCADO 10.00-18 sin 01038 ®2016 HydroCAD Software Solutions LLC Page 16 Summary for Subcatchment 10: M-ELM-10 Runoff = 37.80 cfs @ 12.13 hrs, Volume= 135,191 cf, Depth> 4.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs j Type III 24-hr 25-YR Rainfall=5.76" Area sf CN Description * 62,465 98 Impervious, BLDG * 128,350 98 Impervious, PVMT 192,145 74 >75% Grass cover, Good, HSG C * 5,490 98 Im ervious BLDG Overhang 388,450 86 Weighted Average 192,145 49.46% Pervious Area 196,305 50.54% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft) (ft/sec) (cfs 5.5 50 0.0200 0.15 Sheet Flow, Grass; Short n= 0.150 P2= 3.32" 0.8 125 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.3 80 0.1000 5.O0 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 90 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 35 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.1 20 0.0100 4.91 3.86 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 HDPF 0.6 350 0.0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPF 0.8 510 0.0070 10.36 130.20 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPF 9.1 1,260 Total 11625.09 - PR - Phase 3 Type/1/ 24-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 H droCAD®10.00-18 s/n 01038 ©2016 H droCAD Software Solutions LLC Pacie 17 Subcatchment 10: M-ELM-10 Hydrograph I 1 I F I I I I I E I ! 1 3 1 I E S f € I 42 40- 1 1 I E E 1 I I 1 ! I I I I I I I E F # f I --i__�-�__-}-'--T__r.....1..,._r_"'E___I_ 37.BO ds I -Irypel)l44=hr -E- --E--,---,--,- -E�, 34- -25R�Rai nfal�=�.76'"_,.. _; _ :_ 1 E E I I E I I 3 3 1 i E 3o ' -I u"off area=�.8$,450;sf; -'--; -- ,--;27 _;- ' I 1 } Vol ' 3 1 I 26 -�ur�off ' n e='1E30,'1'91,0 ,- 2z. -,- -I--j- T € ---- 24- l-u 6 o# bepth:i4.1-8"'- E --'- --'-- -- - -3- 1 - { - Y 22 J_ 3 _.i,... ._!_._L__ LL Flow_.L•ength=�1i2.60'_ ' 1 E -- - i I 1 I i ! 3 I E I 1 "•-�� I ���E I I I ! I 1 € 1 7 //''�•.� - y__r__Y__r__E__�__' .....;: _r.__,.._-_1- ---;'"-y r--�_-I___I_-_ 16= 14 -1w. 12 87 1 [ E I € I I ! I t I I I 1 1 € I I I I I , I 1 41 ..[---F--Y--t--r--r--r--I--- 2: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) i 11625.09 - PR - Phase 3 Type 11124-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 H CIroCA0010.00-18 sln 01038 ©2016 H droCAD Software Solutions LLC page 18 Summary for Subcatchment 10B: M-1A-10B Runoff - 2.88 cfs @ 12.12 hrs, Volume= 9,688 cf, Depth> 3.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR Rainfall=5.76" Area (sf) CN Description 2,710 98 impervious, PVMT 33,965 74 >75% Grass cover, Good, HSG C 36,675 76 Weighted Average 33,965 92.61% Pervious Area 2,710 7.39% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftisec) cfs 3.8 50 0.0500 0.22 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 1.7 125 0.0060 1.25 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 360 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8.1 535 Total Subcatchment 10B: M-IA-IOB Hydrograph -------- -- - -- I�Runoff 3 Type 111 ;24-hir 25-YR Railrifalh-5.76 I I ff A I I I I R ?unorea'=36, i 675 sf { I I 1 I 2- ' kunoff Vidjul nq'= 6:80 cf I I I I ] I t 1 I I I I I ! Runoff bepth>3.17" RoW Len th=535' ' I 1 ! '� I -Tc�8r1\-m� 1_ I 11/N-76 I 1 I I I 3 I I 1 1 I I I I I I I 1 ! ! I 1 1 l I I I I ! 1 0 0 1 2 3 4 6 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - PR - Phase 3 Type 11124-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 HydroCAD® 10.00-18 sln 01038 ©2016 HydroCAD Software Solutions LLC Page 19 Summary for Link DP-1: Site Total Inflow Area = 425,125 sf, 46.81% Impervious, Inflow Depth > 4.09" for 25-YR event Inflow — 40.62 cfs @ 12A3 hrs, Volume= 144,879 cf Primary -- 40.62 cfs @ 12A3 hrs, Volume= 144,879 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1: Site Total Hydrograph 1 E k ! 1 121/• --f l-- -- ....E_-�....-I.....r.._.h_._.i_.....I....... _. .r_..,.L.._....I.,....i_' E--j-_E-- --E--{--E--i-- [EIfOW III ry / -I__J--1_-! I__-1_..A__.1..._.I_._�1 40.62.cos _I_�,,,,,I,,,_...1_..,.1._'-1__.J__.F--i__°---`__J-- 1.[]Prima 44= - - � I r / € r 40.62 cfs E 42 Inf orN Ar0a-42-$,12 / / 36 / r• I 1 I { I i I I I I -�=";, E I E I 1 3 F E ! . 32- 1 _ E 28 -- --�--I---1- --!- - --1---'- --'---I-- J-- =- I . � • .�.�I--.�..I... 26-! I I I F I I ' .._i__J.._ _ "` _ C 22- ..L--€---I--E--`'--I---I :.,....W -E-_-I--1_-L__'--J--I--L--'-__?'-_ F__. 1 E € E E I I ';�;'%� t I 1 3 I I } } £ { - 20.W / ---I--7---F--it--E.._�.... ...,..._-L..__i.... .- :;, .,.1_.._...1.,......,-_. r"--r---;--'}--t-----£--18, I ! 3 i { <: 16: _!__J_. E- -�-- � --'--------------I-- {-- I - , • I I I i ! ! � � I [ 3 E I € 4 2`. 0= 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 13 20 21 22 23 24 Time (hours) i 11625.09 - PR - Phase 3 Type 1!! 24-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 H dmCAD010.00-18 sln 01038 ©2016 Fi droCAD Software Solutions LLC Pac ie 20 Summary for Link DP-1A-1B: Rock Ridge Road/Elm Steet Drainage System Inflow Area = 36,675 sf, 7.39% Impervious, Inflow Depth > 3.17" for 25-YR event Inflow - 2,88 cfs @ 12.12 hrs, Volume= 9,688 of Primary - 2.88 cfs @ 12.12 hrs, Volume= 9,688 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt=0.05 hrs Link DP-1A-1 B: Rock Ridge Road/Elm Steet Drainage System Hydrograph I I E I I ! I I I I I I I I F I E I I I k 1 E I [ I 1 1 I E I Q Primary 3- I I 1 I Inflow Area=36,6;7 288Ma E I I I I E I I I I 1 I I I I I ! e 1 I I 1 3 f I 2- I ! I I ! 1 E I € I E E t € E N E 1 I I I I € E f 3 3 f ! } E E t E E 1 h I 3 V € k E I F I I 4 E 4 f E E I € f ! f 3 E I I 1 1 ! € I 0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - PR - Phase 3 Type /H 24-hr 25-YR Rainfall=5.76" Prepared by VHB Printed 2/21/2017 H droCAD®10.00-18 s/n 01038 OO 2016 H droCAD Software Solutions LLC Page 21 Summary for Link DP-ELM-1: Elm Street Basin Inflow Area = 388,450 A 50.54% Impervious, Inflow Depth > 4.18" for 25-YR event Inflow -- 37.80 cfs @ 12.13 hrs, Volume= 135,191 cf Primary 37.80 cfs G 12.13 hrs, Volume= 135,191 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-ELM-1. Elm Street Basin Hydrograph / - -- -�-- -- -----_-- -- -- -- -- -!--1- 1--- —--- -- , I --I € --1— 3760cfs `! i € ! i__.i "r-- E,,. many - l I I F E E Fri I40 , {nfloW Alrea_=388 5,4 3,� 5 38' - -- -- 3fi. 3 Yi E E -- -- - -- - -- -- / _ - _,i T i r l 344 E 32, / _ 1 _ 1 _ 3 _ ! _ ! _ _ i I I 3 1 I I E € 3 I 1 I E I 1 E J � i 28: / -= 2fi: � F i I _ 7 __I_._ .3_... ._ -�--r -F -T T -1-- -- 4n 24- 18: 1 G: J --`- I € j 14- __i__I___E__�_ 11111 1 I C ] [ i E I I t F I I ] 3 3 -1...._ 1__i___k__1__T_____f__ _ .ry.;_ l J V ee 4- I � 2= 0 1 2 3 4 5 fi 7 8 9 10 11 12 13 14 15 1fi 17 18 19 20 21 22 23 24 Time (hours) j I 11625.09 - PR - Phase 3 Type Ill 24-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/2112017 Hy 1D.00-18 slrt 01038 02016 FiydroCAD Software Solutions LLC Page 22, Summary for Subcatchment 10: M-ELM-10 Runoff 43.04 cfs @ 12.13 hrs, Volume= 154,878 cf, Depth> 4.78" a Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR Rainfall=6.40" Area (sf) CN Description 62,465 98 Impervious, BLDG 128,350 98 Impervious, PVMT 192,145 74 >75% Grass cover, Good, HSG C 5,490 98 Impervious, BLDG Overhang 388,450 86 Weighted Average 192,145 49,46% Pervious Area 196,305 50,54% Impervious Area Tc Length Slope Velocity Capacity Description min feet fUft ft/sec cfs 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n=0.150 P2= 3.32" 0.8 125 0.0150 2.49 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.3 80 0.1000 5.09 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 90 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.3 35 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.1 20 0.0100 4.91 3.86 Pipe Channel, 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 HDPE 0.6 350 0.0060 9.59 120.54 Pipe Channel, 48.0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 0.8 510 0.0070 10.36 130.20 Pipe Channel, 48,0" Round Area= 12.6 sf Perim= 12.6' r= 1.00' n= 0.012 HDPE 9.1 1,260 Total i i 11625.09 - PR - Phase 3 Type lil 24-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2121/2017 HydroCAD010.00-18 sfn 01038 02016 HydroCAD Software Solutions LLC Page 23 Subcatchment 10: M-ELM-10 Hydrograph I ! 3 k € I I k I I I 3 } f I I I £ I € ! F I 4e- --- - - - -------- -- -- -- ---- - , I 46_- a. -- --=--�-- -- --'---'--�- -- -- --'---'--J--3--1-----L-- RUnoff I ! I [ I E I l I I gg_(µb Os 44- - -l-- -M-r--r--r--I---r - --r--r--r-�-- --T--r--r--r--I-- 42- -- ':V e ' - r _,f L_.-?.._E_....I_ _I-... - ^'•-f,_.,.!._....E...,...h...,....1..__I__ __1__ __ __£___I__ • � iJ�3 3a= '. 1;00-YID-F ainfall76.40',- f - --;--- E W _ ---- 1 f 3 £ 34 - unotf- °rep.= V [�E.. 1 sIk E Ii 32' 5 ;Mcfi i I ume=' 878;3 iOff Vol I --�--E - • 3 i--- -pith !> 78 26- � ��--� --• L--'--J-- -"3;a..-L--L--�'--'---J___5....1__...1......1...._..F_._...I_.._ - - E 3 0 24. F,IoVv LOngth= 26Q .,. ' .. -I --=--'---'--= -{---'--- ---____-- �' I 3 I - 3 i '_.}... €- _-I' I I F I LL 20 T� 1U: --- ..-I_�-I....1`-T--T---- 16- l• C -„8 Vf` 1 L f V I 1 I E I I 3 F I 14- _1._ ..1--i--Y--T--Y--I---1-- --Y -Y--r-- - -- -- - 12 ; 1 4 E I � F I- E--_I ] 3 E _-f 1-__I � .' E I I I _..}•_..�.....' I 4. I F 2- 0 0 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 1 11625.09 - PR - Phase 3 Type Ili 24-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 H droCAD®10.00-18 sin 01038 ©2016 H LdroCAD Software Solutions LLC Page 24 Summary for Subcatchment 10B: M-1A-10B Runoff - 3.38 cfs @ 12.12 hrs, Volume= 11,378 cf, Depth> 3.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24A0 hrs, dt= 0.05 hrs Type III 24-hr 100-YR Rainfall=6,40" Area (sf) CN Description * 2,710 98 Impervious, PVMT 33,965 74 >75% Grass cover, Good, HSG C 36,675 76 Weighted Average 33,965 92.61% Pervious Area 2,710 7.39% Impervious Area Tc Length: Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 3.8 50 0.0500 0.22 Sheet Flow, Grass: Short n= 0.150 P2= 3.32" 1.7 125 0.0060 1.25 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 360 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8.1 535 Total Subcatchment 106: M-1A-10B Hydrograph I I I I I I 1 � 1 I I f I E I E 3 1 i �Runoff I I I ! 33 (dS 1 I 3 f 1 Type Ili �4 hr t 3 3 --- -i-----. t `.- - ----i 7 r -I-. .. I- -1 - t- -- -- -->---E.,. ..,..E.._ - -- 1,00 YRa>�nall=6.40" I i �- 3 1 1 E ` I I I Runoff Area'36,675sf 3 3 Runoff Volume' 11,378 Cf 3 •--• � Depth�3� E - E,7 I 2- Runoff � ` I I E 3 I ! E y 1 I O Flow Leh9th'-5$5'� �� I I C ��� � ��� " : i --I-- CN=76. _-1 ., -- -- -- - I I 1 ! I I I I I I E I I V- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 11625.09 - PR - Phase 3 Type I1124-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2121/2017 H droCAD®10.00-18 sln 01038 ©2016 H droCAD Software Solutions LLC Page 25 Summary for Link DP-1: Site Total Inflow Area = 425,125 sf, 46.81% Impervious, Inflow Depth > 4.69" for 100-YR event Inflow 46.64 cfs @ 12.12 hrs, Volume= 166,256 cf Primary -- 46.64 cfs @ 12.12 hrs, Volume= 166,256 cf, Atten= 0%,' Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs . Link DP-1: Site Total Hydrograph V1 inflow ♦ } i I 1 i i I i € i I ! ! I I 3 5a� ' _ Primary I'ni#10 -Area=42512 45- - - - ♦ ! 1 1 I 1 i E E I I k I 1 I I 30 -_E- ---- -- f £ 1 3 1 ! # E I E 1 I I ! 25 ! 20 - -I--'--=-- I- f { E } E E E ! } 1 £ I 3 E I I 3 E 1 a- - i I E E € I 1 I I I 5- a- a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) I 11625.09 - PR - Phase 3 Type 11124-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 H droCAD® 10.00-18 sln 01038 02016 H droCAD Software Solutions LLC Page 26 Summary for Link DP-1A-1B: Rock Ridge Road/Elm Steet Drainage System Inflow Area = 36,675 sf, 7.39% impervious, Inflow Depth > 3,72" for 100-YR event Inflow = 3.38 cfs @ 12.12 hrs, Volume= 11,378 of Primary = 3.38 cfs @ 12.12 hrs, Volume= 11,378 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-1A-1 B: Rock Ridge Road/Elm Steet Drainage System Hydrograph I a Inflow I ! I f r 3 1 + { ! I E [ 1 1 f 1 I C1 pri€n8 339 L{8 1 I 1 1 I I 1 I I I ry I I I Inflow A ea=36,67 33a�a 1 I 3 f I 1 I 3 I I I I I 3 I I f E 1 i I -- -- I I ! f I E I I 1 ! I ! I f I 3 { 2_ E E f 1 I I I I I 3 I I 3 I I I 1 I ! I 1 1 I S 1 I I 1 1 ! I I E 1 1 I 1 I I I E I I I I I I I 3 E I I i 1 I E I I I I I 1 1 I I 3 I I 1 I I I 1 I I I 3 1 I I 0 1 2 3 4 S S 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (Yours) i i � I 11625.09 - PR - Phase 3 Type i1124-hr 100-YR Rainfall=6.40" Prepared by VHB Printed 2/21/2017 HydroCAD®10.00-18 sln 01038 @ 2016 HydroCAD Software Solutions LLC Page 27 Summary for Link DP-ELM-1: Elm Street Basin Inflow Area = 388,450 sf, 50.54% Impervious, Inflow Depth > 4.78" for 100-YR event Inflow - 43.04 cfs @ 12.13 hrs, Volume= 154,878 cf Primary -- 43.04 cfs @ 12.13 hrs, Volume= 154,878 cf, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link DP-ELM-1: Elm Street Basin Hydrograph E [ E FM 1 A3.04ds I I I mart 46:" -------E-----i - - - ,-- -- --,---I-- --i-------a--: " /� �- Pri 44= of ©yv-Area= $8y45 A3.64 ds __I__-_____L__I___I__.a__. ----- - -- ------------------------- 42- i 1 �-`i - .w 40. 1__L__—_J__J I I 3 3 ' - -.. 3 - 32 1 -1--'--- I-- i ' -- 3 -- .30z - " E E ! I I I I I I m � �- � l3�i 28zi I ! ! ; I 3 i I I I i 1 I I 1 1 C 22=LL -- - ' - - - - ' --I- -- -- - V _ I - --------------------- L__I__J_. _I__J__ __L____J__ l - ...,..._,"�.._..,...'"� ---r--I--7--r--;-- -- r-- ,', 10: - ; .___'" "i". i t �4 2' 0' 0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Recharge Calcidations Project Name:Additional Area for Building A&C Project No,: 11625.09 Borth Campus Development Date: July 2014 Merrimack College Calculated by: BCS Project Location: Andover/North Andover,MA Rev: Feb 2017 3 MA DFP-Required Recharge Volume(Cubic Feet) HSG Area Recharge Depth' Volume acres In, c.f. A 0.00 0.60 0 B O.DO 0.35 0 C 0.18 0.25 161 D D.00 0.10 0 TOTAL 161 Assumplims: former Massachuselis DEP Infclhakn requirement HSG A=0,60 in;HSG B=0.351n;HSG C=0.261n;HSG D=0.101n. Capture Area Adjustment Required Recharge Volume 161 o.f. Additional Site impervious Area 7,750 s.f. Additional Site Impervious Area Drainage to Recharge Facilities 7,750 s.f. Capture Area Adjustment Factor 1.00 - Percentage of Site Impervious Draining to Recharge Facility 100.00 % Adjusted Required Recharge Volume 161 c.f. Town of Andover-Required Recharge Volume(Cubic Feet) Site Impervious Area 7,750 s.f. Site Total Area 7,750 s.f. %Impervious 1.00 Rv 0.95 A 0.18 acres 5 0.25 Rev 153 0, Provided Recharge Volume(Cubic Feet)and Drawdown Times Subsurface Detentionflnfltratlon System 1-SC-310 Units Infiltration Volumes Provided in System below Outlet at elevation 186 Surface Elevation 217.33 Invert In(6") 214.5 Invert Out(6°) 214.5 Bottom of Stone(6"Depth) 214.0 Approximate Separation Groundwater Elovation(t} 212.0 to Groundwater: 2.0 ft. Depth of Water in System(in) 28 Unit Storage per Chamber(c.f.)* 31 '(per Manufacturer) Number of Units 6 Total Volume(c.f.) 186 Drawdown Analysis: Surface Area 421 S,f. Total Volume 186 c;f. 11vhb1prot1Wat-LD111625.091ssheetskDralnage111625.09-Recharge Calculatlons,PH3_Build A_C.xls Recharge Rate 0.60 inlhr` 'Rawls Rate for Type C soil per Geotech Report Drawdown Time. 30.7 hours Recharge Volume Summary REQUIRED: MassDEP Adjusted Required Recharge Volume 161 c.f. Town of Andover Required Recharge Volume 153 c.f. PROVIDED: Provided Recharge Volume 186 c.f. Drawdown Time 31 hrs 11vhb1projlWat-Lb111625.091ssheetsXDralnsgeX11625.09-Recharge Calculations_PH3_Build A_C.xls 1 G ® Reebatr t � i Project Name:Sakowich Center Expansion Project No.: 11626,09 North Campus Development Date: July 2014 Merrimack College Calculated by: BCB I Project Location: AndoverlNorth Andover,NSA Rev; Feb 2017 i MA DEP-Required Recharge Volume(Cubic Feet) HSG Area Recharge Depth" Volume acres in. c.f. A 0.00 0.80 0 B 0.00 0,35 0 C 0.20 0,25 185 D 0.00 0.10 0 TOTAL 185 Assumollons� former Messachusetis DEP Inf liratioa requirement:HSG A=0.60 In;HSG B=0.35 in;HSG C=0251n;HSG D=0.10 in. Capture Area Adjustment Required Recharge Volume 185 c.f, Total Site Impervious Area 8,860 s.f, 2 „ 0 Total Site Impervous Area Drafna a to Recharge Facilities 701 a.f. ,,, Capture Area Adjustment Factor 1.26 - Percentage of Site Impervious Draining to Recharge Facility 79.12 % [Adjusted Required Recharge Volume 233 c.f. Town of Andover-Required Recharge Volume(Cubic Feet) Site Impervious Area 8,860 s.f. Site Total Area 18,400 s.f. %Impervious 0.48 RV 0.48 A 0.42 acres S 0,25 Rev 185 M. Provided Recharge Volume(Cubic Feet)and Drawdown Times Subsurface Detentlonllnfiltration S stem 1-SC-310 Units Infiltration Volumes Provided in System below Outlet at elevation 246 Surface Elevation 217.33 Invert In(6") 214.5 Invert Out(6') 214.5 Bottom of Stone(6"Depth) 214.0 Approximate Separation Groundwater Elevation(tl 212.0 to Groundwater: 2.0 ft. Depth of Water in System(in) 26 Unit Storage per Chamber(o.f.)" 31 '(per Manufacturer) Number of Units 8 Total Volume(c.f.) 246 Drawdown Analysis: Surface Area 161 s.f. Total Volume 248 c.€. 1lvhblprollWat-LD111625.091ssheelslDralnage111625A9-Recharge Calculafions_PH3 Sakowich.xis Recharge Rate 0.60 infhr` 'Rawls Rate for Type C soil per Geotech Report D€awdown Time; 30.7 hours Recharge Volume Summary REQUIRED: MassDEP Adjusted Required Recharge Volume 233 c.f. Town of Andover Required Recharge Volume 185 c.f. PROVIDED: Provided Recharge Volume 248 c.f. Drawdown Time 31 hrs 11vhMprojlWat-LDkI 1625.091ssheetsQraina9eli 1625.09-Recharge Calculations—PH3,sakov&h.xls UPDATED AT ANDOVER ASSESSORS OFFICE FEBRUARY 16, 2017 Parcel ID Owner Co=Owner Address City/Stateop d 1 0 5 AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 ,t20103 AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 v,2 0104 T 3t 1 Y14NC� A1K3 *,44W C#W4 29 BROOKFIELD RD ANDOVER MA 01810 -.r 2 0105 LYNCH CAROLYN 27 BROOKFIELD RD ANDOVER MA 0181'0 ✓2 0 106 HARRER WILLIAM M HARRER ANNA V TE 23 BROOKFIELD RD ANDOVER MA 01810 ✓2 0107 GIBSON CRAIG D LESLEY G GIBSON TE 17 BROOKFIELD RD ANDOVER MA 01810 .•1 2 0 108 LEVINE STEPHEN H LEVINE SANDRA KTE 13 BROOKFIELD RD ANDOVER MA 01810 /2 0 109 BUSTA THOMAS =, GRACE BUSTA. 9 BROOKFIELD RD ANDOVER MA 01810 ✓2 0110 BEAN CURTIS H SARA 14 BEAN 5 BROOKFIELD RD ANDOVER MA 01810 .✓ 2 0111 7amAwA[., 1 BROOKFIELD RD ANDOVER MA 01810 /2 0 112 HUDKINS THOMAS R JUDITH K HUDKINS TE 151 ELM ST ANDOVER MA 01810 2 0 45 KARNIK ASHUTOSH P SMITAA KARNIK TE 188 ELM ST ANDOVER MA 01810 ✓ 2 0 46 CARLEO JR ROBERT A MCCARRON TE DIANE M 1 NAPIER RD ANDOVER MA 01810 ✓ 2 0 48 MERRIMACK COLLEGE INC 315 TURNPIKE ST NORTH ANDOVER MA 01845 'r 2 0 49 WILSON MATTHEW R WILSON MARIA TE 200 ELM ST ANDOVER MA 01810 205 GRACE M BERNARDIN IRREVOC TR BERNARDIN ROBERT+PETER TRS 138 ELM ST ANDOVER MA 01810 2 0 51 AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 'j 2 0 51 A AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 'j 2052 SALLY SHOCKRO 33 ROCK RIDGE RD ANDOVER MA 01810 ✓ 2 0 53 -P AGE t►hgejUA aCV- C4tL*q-G 3t5 p11GE W 27 ROCK RIDGE RD ANDOVER MA 01810 J 2054 '+ ;�"',�&r eci t N1-4"4µQCC COLtL"t$ 31S - tIC6 ST' 23 ROCK RIDGE RD ANDOVER MA 01810 ✓ 2055 RECK JOANNA- 15 ROCK RIDGE RD ANDOVER MA 01810 ✓ 2056 DAVID JOHNSON 61 BROOKFIELD RD ANDOVER MA 01810 . 206 EVERETT HOME BUILDERS PO BOX 508 MALDEN MA 02148 ✓ 2 0 64 HASKELL BETH C RAYMOND R JEFFREY JT 18 FOX HILL RD ANDOVER MA 01810 2 0 65 DIETZ JOHN P 24'FOX HILL RD ANDOVER MA 01810 ✓ 2 0 66 OUELLETTE BERTRAND A CAMILI E L OUELLETTE TE 30 FOX HILL RD ANDOVER MA 01810 ✓., 2 0 67 LANDRY JR JAMES L LANDRY TE KIMBERLY R 15 WOODCLIFF RD ANDOVER MA 01810 2068 HASKELL BETH RAYMOND RICHARD J TE 14 FOX HILL RD ANDOVER MA 01810 2076 MERRIMACK COLLEGE 7 ROCK RIDGE RD ANDOVER MA 01810 ✓ 2 0 77 MERRIMACK COLLEGE 185 ELM ST ANDOVER MA 01810 ✓ 2096 MORAVA NORMAL 11 FOX HILL RD ANDOVER MA 01810 2 0 97 THOMSON ALA NW SUSAN THOMSON TE 41 FOX HILL RD ANDOVER MA 01810 ✓ 2 0 98 GRUNDEEN PAULETTE 37 FOX HILL RD ANDOVER MA 01810 ✓ 2099 HAYWOOD CLAIRE F LE 33 FOX HILL RD ANDOVER MA 01810 ✓ 21 0 139 MAYE ROBERT J LISA HOLIHAN MAYE TE 139143 ELM ST ANDOVER MA 01810 . . . . ✓ 21 0144 MAYE LISA H ' )AA`IS 143 ELM ST ANDOVER MA 01810 ✓ 21 0147 AVIS PO BOX 5097 ANDOVER MA 01810 ✓ 210156 WANG HANLI JHANG JU TE 63 LUCERNE DR ANDOVER MA 01810 210157 E 59 LUCERNE DR ANDOVER MA 01810 ✓ 210158 MR MARAQ C� A 55 LUCERNE DR ANDOVER MA 01810 ✓. 210159 M NH 49 LUCERNE DR ANDOVER MA 01810 ✓ 210 160 SPURR GREGORY W IIl BONNIE A SPURR TE 43 LUCERNE DR ANDOVER MA 01810 ✓ 210161 J 314E" k5 JT 39 LUCERNE DR ANDOVER MA 01810 ✓ 301 OWNER UNKNOWN TT % COLLECTOR/TREASURER 36 BARTLET ST ANDOVER MA 01810 ✓. 302 PAGLIA PETER M PAGLIA LORI M TE 3 FARNSWORTH•RD ANDOVER MA 01810 V' 303 ONE 47 ELM ST REALTY TRUST WILLIAM +BERNICE DOWNS TRS 147 ELM ST ANDOVER MA 01810 v 304 AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 305 AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 ✓ 3 0 5 A AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 V 3 0 5 B AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 ✓ 306 MERRIMACK COLLEGE INC 315 TURNPIKE ST NORTH ANDOVER MA 01845 y 4061 TOWN OF ANDOVER CONSERVATION COMMISSION 36 BARTLET ST ANDOVER MA 01810 v' 4062 KWOLYK DONA M 124 SUMMER ST ANDOVER MA 01810 4063 KARLBERG JEFFREYA KARLBERG TE MICHELE 1 134 SUMMER ST ANDOVER MA 01810 ✓ 4064 WOODWARD GEORGE S HOPE P WOODWARD TE 138 SUMMER ST ANDOVER MA D1810 4065 ST JEAN DAVID L 144 SUMMER ST ANDOVER MA 01810 4066 MERRIMACK COLLEGE CIO DONNA COUTURE 315 TURNPIKE ST NORTH ANDOVER MA 01845 V 4057 KEIL MARK A ELIZABETH L ANDERSON TE 148 SUMMER ST ANDOVER MA 01810 4058 EDHOLM JAMES L EDHOLM KATHLEEN D TE 158 SUMMER ST ANDOVER MA 01810 ✓ . 4069 VALLEAU A REED LOUISE D VALLEAU TE 166 SUMMER ST ANDOVER MA 01810 Y 4 0 70 DONALD E JOHNSON IRREV TRUST JANE W JOHNSON 1RREV TRUST 4 APPLECREST RD ANDOVER MA 01810 ✓ 4071 BANZI FREDERICK J JEAN M BANZI TE 6 APPLECREST RD ANDOVER MA 01810 V 4072 AUGUSTINIAN COLLEGE THE MERRIMACK VALLEY 315 TURNPIKE ST NORTH ANDOVER MA 01845 ✓ . 4 0 73 MERRIMACK COLLEGE JL4wM A SAuGE 315 TURNPIKE ST NORTH ANDOVER MA 01845 ✓ 4077 TT 19 DOWNING ST ANDOVER MA 01810 ✓ 4078 PELTIER LEONARD J VERONICA G PELTIER 17 DOWNING ST ANDOVER MA 01810 . 4079 LAHOOD JOSEPH W SANDRA J LAHOOD TE 15 DOWNING ST ANDOVER MA 01810 4080 THIRTEEN DOWNING STREET RT II O'BRIEN THOMAS+GERALDINE TRS 13 DOWNING ST ANDOVER MA 01810 ✓ 4081 LllPKINS PA4" UWS SLSSM6 S&S }11 DOWNING ST ANDOVER MA 01810 ✓ 4082 ROMAN REALTY TRUST' BARBARA L ROMAN TR 9 DOWNING ST ANDOVER MA 01810 ✓ 4083 MONTANI ANN M GEORGE V O'REILLY ETAL 7 DOWNING ST ANDOVER MA 01810 4084 TE 5 DOWNING ST ANDOVER MA 01810 IUA5Eir.T A sw%,vf l +�Y D St tit 4 0 85 Leo CHApj N&FEN NfSN 3©OWNING ST AN©OVER MA 01810 �/ 4086 LYNCH JOHN K LYNCH JANE B TE 1 DOWNING•ST ANDOVER MA 01810 NOTIFICATION TO ABUTTERS UNDER THE MASSACHUSETTS WETLANDS PROTECTION ACT AND THE TOWN OF ANDOVER WETLANDS PROTECTION BYLAW In accordance with the second paragraph of Massachusetts General Laws Chapter 131, section 40 and the Town of Andover Wetlands Protection Bylaw,you are hereby notified of the following: The Applicant, Merrimack College, has filed a request for an Amended Order of Conditions with the Andover Conservation Commission pertaining to alteration of stormwater flows within areas subject to the Wetlands Protection Act. This work is proposed at the Merrimack College campus located at 315 Turnpike Street in North Andover. The request for an Amended Order of Conditions relates to a ;minor modification to the previously(2016) approved North Campus Academic, which included three new academic buildings in addition to two residential buildings constructed on an approximately 4.8-acre site along Flaherty Drive; north of the Sakowich Student Center and west of Austin Hall. The proposed modification changes the footprints of 2 of the buildings along Rock Ridge Road to accommodate program needs,and includes an expansion to the existing Sakowich Campus Center between the existing loading dock,Flaherty Way and Deegan Walk. Copies of the Request for Amended Order may be examined at the Andover Conservation Connnission office located in'the Town Hall at 36 Bartlett Street between the hours of 8:00 am to 3:00 pin Monday through Friday.For more information, call the Andover Conservation Commission at(978)623-8311.The Request for Amended Order may also be examined at the offices of Vanasse Hangen Brustlin, Inc. by appointment.For niore information call Chris Lovett at(617)924-1770. Copies of the Request for Amended Order of Conditions may be obtained frorn the Andover Conservation Commission or by calling Jeff Koetteritz at Vanasse Hangen Brustlin,Inc. at(617) 924-1770. You may be charged for the cost of tine copy. Notice of the Public Hearing, including its date, time and place, will be published in a local newspaper at least 5 days in advance, and will be posted in the Town Hall not less than 48 hours in advance of the Hearing. You may also contact the Department of Environmental Protection Northeast Regional Office at(978)694- 3200 for more information about this application or the Wetlands Protection Act.