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HomeMy WebLinkAboutWPO201700019 Calculations WPO VSMP 2017-04-03 Scottsville Elementary School Security Addition ALBEMARLE COUNTY, VIRGINIA MINOR SITE PLAN AMENDMENT DESIGN CALCULATIONS & NARRATIVE FEBRUARY 21, 2017 REVISED APRIL 3, 2017 . a •• TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 434.327.1688 zr �CRAIG 3.KOTARSKI - Lic.No.0402048507 10 I/3 117 ` ; :. 4GNAL4 4¢ Table of Contents Section Title 1 Project Narrative 2 Outlet Protection Sizing 3 Stormwater Quantity Calculations 4 Pre-Developed HydroCAD Calculations 5 Post-Developed HydroCAD Calculations 6 Virginia Runoff Reduction Method ReDevelopment Worksheet Project Narrative: This project includes a building addition to Scottsville Elementary School, an update bus loop, additional parking, sidewalk and associated site work. Limits of disturbance is 0.75 acres. Water Quality: Currently there exists 0.50 acres of managed turf and'b.23 acres of impervious cover witl}in7the ite limits. In the proposed condition there will be 0.37 acres-of managed turf and 0.38 acres of impervious cover. Per the Virginia Runoff Reduction Redevelopment Spreadsheet,this will require that 0.30 lb/yr to be removed. This required reduction is being met through a surplus removal of 0.351b/yr that has been achieved on the Woodbrook Elementary School project. See Plan WP0201600075. This surplus removal will be applied to this project, as ownership for both parcels is the same, the Albemarle County School Board, per 9vac25-870-69 Section A Part 5. Water Quantity: The majority of the disturbed area drains to the existing stormwater management facility to the south west. Out flow from facility flows to the north to the ditch along Route 20. A small amount of the disturbed area is not routed and also drains to the north to the ditch along route 20. These two flows converge at the point of analysis shown on sheet C6.0. All other flows to this point remain the unchanged. For channel protection, the one-year peek flow rate from the total disturbed area routed and unrouted pre and post developed has been analyzed and the required reduction has been calculated as 0.57 CFS per the energy balance equation, 9VAC25-870-66. This has been achieved through modifying the existing stormwater management facility through excavating to add additional storage capacity and modifying the outflow structure. An analysis of the pre and post one-year flows from the system yields a reduction of 0.66 CFS. For flood protection, the pre- developed 10-year peek flow from the stormwater management facility has been maintained. See Sheet C7.0 and below for calculations below. Channel Protection (Energy Balance): The energy balance equation has been applied to the 1 year storm for the 0.75 acres of disturbed area as shown below. 0.9 * (QPRE * RI/PRE)/ QPost < RVPOST 1.18 + 0.20 cfs <_ 0.9 * ((0.92 + 0.2)c f s * (0.014 + 0.066)ac f t)/ (0.085 + 0.014ac f t) 1.38 cfs < 0.81 cfs The Energy Balance requires that the post-developed 1 year flow be reduced by 1.38 cfs -0.81 cfs =0.57 cfs or more. The existing stormwater management facility has been modified to achieve the required reduction in outflow from disturbed area at the point of analysis. All other contributing flows at that point remain unchanged. Existing pre-developed from SWM facility and unrouted disturbed area to the point of analysis Q1 = 5.39 cfs Q10= 13.71cfs proposed post-developed from modified SWM facility and unrouted disturbed area to the point of analysis Q1 =4.73 cfs Q10= 13.56 cfs 1 year flow has been reduced by 5.39 cfs - 4.73 cfs =0.66 cfs meeting the Energy Balance requirement. Flood Protection (10 year storm): i Post-Developed Q105 Pre-Developed Qio 12.88cfs 13.71cfs 1791 - III £-81'£ a2e1d SJS-VQS11 :azinos 3332 — N 0 01 t•t1 Nji, 4. ^ V 30 v ovo zv, 5 ° C 11 0.v J c N 3 (" CD rt. K O N -S D O O O .O r- c ,-IMIl itaastsfti= o w -i m 0 m --I aillialltsmmagamag'WIC 73 a■aagitrs '=msia_ As �anum" : 0 O rIV tri ._ 1M I-� W GZ -en11111111111111111111111INIMIIIIIIIIIIIII:VIERS ESN= -.. ..-.. ..... t=lf11[ i zw t-,-- 11-11 4•*,—. 111111111111111111111111111 , t r o ki „,o v, . Si:- r lik IV i,,n -o ° ° CI to - 7 1,,,o; is ki o W1114 _= - wit.0, 4 - a� . r t 0.. r m Si")' i � �'Ly --- ..r . ..?? ti-. ' i._.____.-. cx i is C r 0 • { em -'—_ moi . . :- 0O 1+ N W j1 o d50 Riprap Size, feet C T 81 £ Z66I < 4S > Ex. SW Facility Drains a Area Pre-Dev Disturbed Are Routed /'N EX. SWM Faclity 411 6L Pre-Dev Disturbed Area Unrouted Point of Analysis (Subca) Reach 'on. Routing Diagram for Pre Prepared by Timmons Group, Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Pre Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 2.360 74 >75% Grass cover, Good, HSG C (2S, 4S, 5S) 1.290 98 Paved parking, HSG C (2S, 4S, 5S) 3.650 82 TOTAL AREA Pre Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 3 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 3P 389.91 389.62 53.0 0.0055 0.011 24.0 0.0 0.0 Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 2S: Ex. SWM Facility Drainage Area Runoff = 4.55 cfs @ 12.15 hrs, Volume= 0.327 af, Depth> 1.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 1 YR Rainfall=3.04" Area (ac) CN Description 1.040 98 Paved parking, HSG C 1.860 74 >75%Grass cover, Good, HSG C 2.900 83 Weighted Average 1.860 64.14% Pervious Area 1.040 35.86% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.7 200 0.0300 0.17 Sheet Flow, Grass: Dense n= 0.240 P2= 3.68" 1.8 150 0.0400 1.40 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 21.5 350 Total Subcatchment 2S: Ex. SWM Facility Drainage Area Hydrograph 5- ®Runoff 14.55 cfs I Type II 24-hr 4- 1 YR Ra nfall_3 04" Runoff Area=2.900 ac 3- Runoff Volume_0.327 af Runoff Depth>1.35" Flow Length=350' 2- Tc=21.5 min - CN=83 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 5 Hydrograph for Subcatchment 2S: Ex. SWM Facility Drainage Area Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.10 0.00 0.00 18.60 2.83 1.31 0.12 3.30 0.12 0.00 0.00 18.90 2.85 1.32 0.12 3.60 0.13 0.00 0.00 19.20 2.86 1.33 0.11 3.90 0.14 0.00 0.00 19.50 2.87 1.35 0.11 4.20 0.15 0.00 0.00 19.80 2.89 1.36 0.10 4.50 0.17 0.00 0.00 4.80 0.18 0.00 0.00 5.10 0.20 0.00 0.00 5.40 0.21 0.00 0.00 5.70 0.23 0.00 0.00 6.00 0.24 0.00 0.00 6.30 0.26 0.00 0.00 6.60 0.28 0.00 0.00 6.90 0.29 0.00 0.00 7.20 0.31 0.00 0.00 7.50 0.33 0.00 0.00 7.80 0.35 0.00 0.00 8.10 0.37 0.00 0.00 8.40 0.39 0.00 0.00 8.70 0.42 0.00 0.00 9.00 0.45 0.00 0.00 9.30 0.48 0.00 0.01 9.60 0.51 0.00 0.02 9.90 0.54 0.01 0.03 10.20 0.58 0.01 0.04 10.50 0.62 0.02 0.06 10.80 0.67 0.03 0.08 11.10 0.74 0.05 0.12 11.40 0.83 0.07 0.18 11.70 1.08 0.16 0.36 12.00 2.02 0.71 2.79 12.30 2.17 0.81 3.11 12.60 2.26 0.88 1.12 12.90 2.33 0.93 0.61 13.20 2.38 0.97 0.45 13.50 2.43 1.00 0.37 13.80 2.47 1.03 0.32 14.10 2.50 1.06 0.28 14.40 2.54 1.08 0.25 14.70 2.57 1.11 0.23 15.00 2.59 1.13 0.22 15.30 2.62 1.15 0.21 15.60 2.65 1.17 0.19 15.90 2.67 1.18 0.18 16.20 2.69 1.20 0.16 16.50 2.71 1.22 0.16 16.80 2.73 1.23 0.15 17.10 2.75 1.25 0.15 17.40 2.77 1.26 0.14 17.70 2.78 1.27 0.14 18.00 2.80 1.29 0.13 18.30 2.82 1.30 0.13 Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 4S: Pre-Dev Disturbed Area Routed Runoff = 0.92 cfs @ 12.15 hrs, Volume= 0.066 af, Depth> 1.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 1 YR Rainfall=3.04" Area (ac) CN Description 0.460 74 >75%Grass cover, Good, HSG C 0.190 98 Paved parking, HSG C 0.650 81 Weighted Average 0.460 70.77% Pervious Area 0.190 29.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 4S: Pre-Dev Disturbed Area Routed Hydrograph 1 ®Runoff 10.92 cfs I Type II 24-hr 1 YR Rainfall=3.04" y Runoff Area=0.650 ac Runoff Volume=0.066 af ri Runoff Depth>1.22" LL Tc=21.5 min CN=81 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 7 Hydrograph for Subcatchment 4S: Pre-Dev Disturbed Area Routed Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.10 0.00 0.00 18.60 2.83 1.19 0.03 3.30 0.12 0.00 0.00 18.90 2.85 1.20 0.02 3.60 0.13 0.00 0.00 19.20 2.86 1.21 0.02 3.90 0.14 0.00 0.00 19.50 2.87 1.22 0.02 4.20 0.15 0.00 0.00 19.80 2.89 1.23 0.02 4.50 0.17 0.00 0.00 4.80 0.18 0.00 0.00 5.10 0.20 0.00 0.00 5.40 0.21 0.00 0.00 5.70 0.23 0.00 0.00 6.00 0.24 0.00 0.00 6.30 0.26 0.00 0.00 6.60 0.28 0.00 0.00 6.90 0.29 0.00 0.00 7.20 0.31 0.00 0.00 7.50 0.33 0.00 0.00 7.80 0.35 0.00 0.00 8.10 0.37 0.00 0.00 8.40 0.39 0.00 0.00 8.70 0.42 0.00 0.00 9.00 0.45 0.00 0.00 9.30 0.48 0.00 0.00 9.60 0.51 0.00 0.00 9.90 0.54 0.00 0.00 10.20 0.58 0.00 0.00 10.50 0.62 0.01 0.01 10.80 0.67 0.02 0.01 11.10 0.74 0.03 0.02 11.40 0.83 0.05 0.03 11.70 1.08 0.13 0.07 12.00 2.02 0.61 0.55 12.30 2.17 0.71 0.64 12.60 2.26 0.78 0.23 12.90 2.33 0.82 0.13 13.20 2.38 0.86 0.09 13.50 2.43 0.89 0.08 13.80 2.47 0.92 0.07 14.10 2.50 0.95 0.06 14.40 2.54 0.97 0.05 14.70 2.57 0.99 0.05 15.00 2.59 1.01 0.05 15.30 2.62 1.03 0.04 15.60 2.65 1.05 0.04 15.90 2.67 1.06 0.04 16.20 2.69 1.08 0.04 16.50 2.71 1.09 0.03 16.80 2.73 1.11 0.03 17.10 2.75 1.12 0.03 17.40 2.77 1.14 0.03 17.70 2.78 1.15 0.03 18.00 2.80 1.16 0.03 18.30 2.82 1.17 0.03 Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Runoff = 0.20 cfs @ 12.14 hrs, Volume= 0.014 af, Depth> 1.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 1 YR Rainfall=3.04" Area (ac) CN Description 0.040 74 >75% Grass cover, Good, HSG C 0.060 98 Paved parking, HSG C 0.100 88 Weighted Average 0.040 40.00% Pervious Area 0.060 60.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Hydrograph Runoff 02, Iozods 0.19; Type II 24-hr 0.18: 1 YR Rainfall=3.04" 0.17' Runoff Area ._0.100 ac 0.147! Runoff Volume=0.014 of .. 0.13= t 0.12= Runoff Depth>1.71" 0.11 r LL 0.1-- Te_21.5 min 0.09= 0.083 CN=88 0.07-- 0.06t 0.05, 0.04_ 0.03 0 02 0.01 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 9 Hydrograph for Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.10 0.00 0.00 18.60 2.83 1.67 0.00 3.30 0.12 0.00 0.00 18.90 2.85 1.68 0.00 3.60 0.13 0.00 0.00 19.20 2.86 1.69 0.00 3.90 0.14 0.00 0.00 19.50 2.87 1.71 0.00 4.20 0.15 0.00 0.00 19.80 2.89 1.72 0.00 4.50 0.17 0.00 0.00 4.80 0.18 0.00 0.00 5.10 0.20 0.00 0.00 5.40 0.21 0.00 0.00 5.70 0.23 0.00 0.00 6.00 0.24 0.00 0.00 6.30 0.26 0.00 0.00 6.60 0.28 0.00 0.00 6.90 0.29 0.00 0.00 7.20 0.31 0.00 0.00 7.50 0.33 0.00 0.00 7.80 0.35 0.00 0.00 8.10 0.37 0.01 0.00 8.40 0.39 0.01 0.00 8.70 0.42 0.01 0.00 9.00 0.45 0.02 0.00 9.30 0.48 0.03 0.00 9.60 0.51 0.03 0.00 9.90 0.54 0.04 0.00 10.20 0.58 0.06 0.00 10.50 0.62 0.07 0.00 10.80 0.67 0.09 0.01 11.10 0.74 0.12 0.01 11.40 0.83 0.16 0.01 11.70 1.08 0.30 0.02 12.00 2.02 0.98 0.13 12.30 2.17 1.10 0.13 12.60 2.26 1.18 0.05 12.90 2.33 1.24 0.02 13.20 2.38 1.28 0.02 13.50 2.43 1.32 0.01 13.80 2.47 1.36 0.01 14.10 2.50 1.38 0.01 14.40 2.54 1.41 0.01 14.70 2.57 1.44 0.01 15.00 2.59 1.46 0.01 15.30 2.62 1.49 0.01 15.60 2.65 1.51 0.01 15.90 2.67 1.53 0.01 16.20 2.69 1.54 0.01 16.50 2.71 1.56 0.01 16.80 2.73 1.58 0.01 17.10 2.75 1.60 0.01 17.40 2.77 1.61 0.01 17.70 2.78 1.63 0.01 18.00 2.80 1.64 0.01 18.30 2.82 1.66 0.00 Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 10 Summary for Pond 3P: EX. SWM Faclity Inflow Area= 3.550 ac, 34.65%Impervious, Inflow Depth > 1.33" for 1 YR event Inflow = 5.48 cfs @ 12.15 hrs, Volume= 0.393 af Outflow = 5.20 cfs @ 12.20 hrs, Volume= 0.377 af, Atten= 5%, Lag= 2.9 min Primary = 5.20 cfs @ 12.20 hrs, Volume= 0.377 af Routing by Stor-Ind method, Time Span= 3.00-20.01 hrs, dt= 0.03 hrs/3 Peak Elev= 393.60' @ 12.20 hrs Surf.Area= 3,980 sf Storage= 1,829 cf Plug-Flow detention time= 25.0 min calculated for 0.377 af (96%of inflow) Center-of-Mass det. time= 9.9 min ( 812.1 - 802.2 ) Volume Invert Avail.Storage Storage Description #1 393.00' 4,931 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 393.00 1,900 0 0 393.50 3,839 1,435 1,435 394.00 4,540 2,095 3,530 394.30 4,800 1,401 4,931 Device Routing Invert Outlet Devices #1 Primary 389.91' 24.0" Round Culvert L= 53.0' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 389.91'/389.62' S= 0.0055 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight &clean, Flow Area= 3.14 sf #2 Device 1 393.26' 24.0"x 24.0"Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=5.18 cfs @ 12.20 hrs HW=393.60' (Free Discharge) L�Culvert (Passes 5.18 cfs of 24.81 cfs potential flow) 2_Orifice/Grate (Weir Controls 5.18 cfs @ 1.91 fps) Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 11 Pond 3P: EX. SWM Faclity 6 Hydrograph ■Inflow II Inflow Area=3.550 a®® ■I Primary 5 Peak EIev=393.60' Storage-1 ,829 cf 4 3 3 LL 2 1 0 A i 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pond 3P: EX. SWM Faclity Stage-Discharge ®Primary 394-- c 0 m W 393 � , � � . 0 2 4 6 8 10 12 14 • 16 18 Discharge (cfs) Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 12 Pond 3P: EX. SWM Faclity Stage-Area-Storage Surface/Horizontal/Wetted Area(sq-ft) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500Surface ®Storage 394 0 W 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 Storage(cubic-feet) Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 13 Hydrograph for Pond 3P: EX. SWM Faclity Time Inflow Storage Elevation Primary (hours) (cfs) (cubic-feet) (feet) (cfs) 3.00 0.00 0 393.00 0.00 3.60 0.00 0 393.00 0.00 4.20 0.00 0 393.00 0.00 4.80 0.00 0 393.00 0.00 5.40 0.00 0 393.00 0.00 6.00 0.00 0 393.00 0.00 6.60 0.00 0 393.00 0.00 7.20 0.00 0 393.00 0.00 7.80 0.00 0 393.00 0.00 8.40 0.00 0 393.00 0.00 9.00 0.00 1 393.00 0.00 9.60 0.02 21 393.01 0.00 10.20 0.04 82 393.04 0.00 10.80 0.09 222 393.11 0.00 11.40 0.22 532 393.23 0.00 12.00 3.34 1,284 393.46 2.34 12.60 1.35 1,131 393.42 1.63 13.20 0.54 867 393.34 0.58 13.80 0.39 813 393.32 0.41 14.40 0.30 782 393.31 0.31 15.00 0.27 767 393.31 0.27 15.60 0.23 755 393.30 0.24 16.20 0.20 743 393.30 0.21 16.80 0.18 735 393.30 0.19 17.40 0.17 730 393.30 0.17 18.00 0.16 724 393.29 0.16 18.60 0.15 719 393.29 0.15 19.20 0.14 714 393.29 0.14 19.80 0.12 709 393.29 0.13 Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 14 Stage-Discharge for Pond 3P: EX. SWM Faclity Elevation Primary Elevation Primary Elevation Primary (feet) (cfs) (feet) (cfs) (feet) (cfs) 393.00 0.00 393.52 3.47 394.04 17.01 393.01 0.00 393.53 3.67 394.05 17.12 393.02 0.00 393.54 3.88 394.06 17.23 393.03 0.00 393.55 4.09 394.07 17.33 393.04 0.00 393.56 4.30 394.08 17.44 393.05 0.00 393.57 4.52 394.09 17.55 393.06 0.00 393.58 4.74 394.10 17.65 393.07 0.00 393.59 4.96 394.11 17.76 393.08 0.00 393.60 5.19 394.12 17.86 393.09 0.00 393.61 5.42 394.13 17.96 393.10 0.00 393.62 5.65 394.14 18.07 393.11 0.00 393.63 5.89 394.15 18.17 393.12 0.00 393.64 6.13 394.16 18.27 393.13 0.00 393.65 6.37 394.17 18.37 393.14 0.00 393.66 6.62 394.18 18.47 393.15 0.00 393.67 6.87 394.19 18.57 393.16 0.00 393.68 7.12 394.20 18.67 393.17 0.00 393.69 7.38 394.21 18.77 393.18 0.00 393.70 7.64 394.22 18.87 393.19 0.00 393.71 7.90 394.23 18.97 393.20 0.00 393.72 8.16 394.24 19.07 393.21 0.00 393.73 8.43 394.25 19.16 393.22 0.00 393.74 8.70 394.26 19.26 393.23 0.00 393.75 8.97 394.27 19.36 393.24 0.00 393.76 9.25 394.28 19.45 393.25 0.00 393.77 9.53 394.29 19.55 393.26 0.00 393.78 9.81 394.30 19.64 393.27 0.03 393.79 10.09 393.28 0.07 393.80 10.38 393.29 0.14 393.81 10.67 393.30 0.21 393.82 10.96 393.31 0.29 393.83 11.26 393.32 0.38 393.84 11.56 393.33 0.48 393.85 11.86 393.34 0.59 393.86 12.16 393.35 0.71 393.87 12.46 393.36 0.83 393.88 12.77 393.37 0.95 393.89 13.08 393.38 1.09 393.90 13.39 393.39 1.23 393.91 13.71 393.40 1.37 393.92 14.03 393.41 1.52 393.93 14.35 393.42 1.67 393.94 14.67 393.43 1.83 393.95 14.99 393.44 2.00 393.96 15.32 393.45 2.17 393.97 15.65 393.46 2.34 393.98 15.98 393.47 2.52 393.99 16.32 393.48 2.70 394.00 16.57 393.49 2.89 394.01 16.68 393.50 3.08 394.02 16.79 393.51 3.27 394.03 16.90 Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 15 Stage-Area-Storage for Pond 3P: EX. SWM Faclity Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 393.00 1,900 0 394.04 4,575 3,712 393.02 1,978 39 394.06 4,592 3,803 393.04 2,055 79 394.08 4,609 3,895 393.06 2,133 121 394.10 4,627 3,988 393.08 2,210 164 394.12 4,644 4,081 393.10 2,288 209 394.14 4,661 4,174 393.12 2,365 256 394.16 4,679 4,267 393.14 2,443 304 394.18 4,696 4,361 393.16 2,520 354 394.20 4,713 4,455 393.18 2,598 405 394.22 4,731 4,549 393.20 2,676 458 394.24 4,748 4,644 393.22 2,753 512 394.26 4,765 4,739 393.24 2,831 568 394.28 4,783 4,835 393.26 2,908 625 394.30 4,800 4,931 393.28 2,986 684 393.30 3,063 745 393.32 3,141 807 393.34 3,219 870 393.36 3,296 935 393.38 3,374 1,002 393.40 3,451 1,070 393.42 3,529 1,140 393.44 3,606 1,211 393.46 3,684 1,284 393.48 3,761 1,359 393.50 3,839 1,435 393.52 3,867 1,512 393.54 3,895 1,589 393.56 3,923 1,668 393.58 3,951 1,746 393.60 3,979 1,826 393.62 4,007 1,906 393.64 4,035 1,986 393.66 4,063 2,067 393.68 4,091 2,148 393.70 4,119 2,231 393.72 4,147 2,313 393.74 4,175 2,396 393.76 4,204 2,480 393.78 4,232 2,565 393.80 4,260 2,650 393.82 4,288 2,735 393.84 4,316 2,821 393.86 4,344 2,908 393.88 4,372 2,995 393.90 4,400 3,083 393.92 4,428 3,171 393.94 4,456 3,260 393.96 4,484 3,349 393.98 4,512 3,439 394.00 4,540 3,530 394.02 4,557 3,620 Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 16 Summary for Link 6L: Point of Analysis Inflow Area= 3.650 ac, 35.34% Impervious, Inflow Depth > 1.29" for 1 YR event Inflow = 5.39 cfs @ 12.19 hrs, Volume= 0.391 of Primary = 5.39 cfs Qa 12.19 hrs, Volume= 0.391 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 3.00-20.01 hrs, dt= 0.03 hrs Link 6L: Point of Analysis Hydrograph 6 ■Inflow Inflow Area=3.650 a .Pnmary 5 4 N V 3 .2 2 0 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 17 Hydrograph for Link 6L: Point of Analysis Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 3.00 0.00 0.00 0.00 18.60 0.15 0.00 0.15 3.30 0.00 0.00 0.00 18.90 0.15 0.00 0.15 3.60 0.00 0.00 0.00 19.20 0.14 0.00 0.14 3.90 0.00 0.00 0.00 19.50 0.14 0.00 0.14 4.20 0.00 0.00 0.00 19.80 0.13 0.00 0.13 4.50 0.00 0.00 0.00 4.80 0.00 0.00 0.00 5.10 0.00 0.00 0.00 5.40 0.00 0.00 0.00 5.70 0.00 0.00 0.00 6.00 0.00 0.00 0.00 6.30 0.00 0.00 0.00 6.60 0.00 0.00 0.00 6.90 0.00 0.00 0.00 7.20 0.00 0.00 0.00 7.50 0.00 0.00 0.00 7.80 0.00 0.00 0.00 8.10 0.00 0.00 0.00 8.40 0.00 0.00 0.00 8.70 0.00 0.00 0.00 9.00 0.00 0.00 0.00 9.30 0.00 0.00 0.00 9.60 0.00 0.00 0.00 9.90 0.00 0.00 0.00 10.20 0.00 0.00 0.00 10.50 0.00 0.00 0.00 10.80 0.01 0.00 0.01 11.10 0.01 0.00 0.01 11.40 0.01 0.00 0.01 11.70 0.28 0.00 0.28 12.00 2.47 0.00 2.47 12.30 4.53 0.00 4.53 12.60 1.68 0.00 1.68 12.90 0.86 0.00 0.86 13.20 0.60 0.00 0.60 13.50 0.49 0.00 0.49 13.80 0.42 0.00 0.42 14.10 0.36 0.00 0.36 14.40 0.32 0.00 0.32 14.70 0.30 0.00 0.30 15.00 0.28 0.00 0.28 15.30 0.26 0.00 0.26 15.60 0.25 0.00 0.25 15.90 0.23 0.00 0.23 16.20 0.21 0.00 0.21 16.50 0.20 0.00 0.20 16.80 0.19 0.00 0.19 17.10 0.19 0.00 0.19 17.40 0.18 0.00 0.18 17.70 0.17 0.00 0.17 18.00 0.17 0.00 0.17 18.30 0.16 0.00 0.16 Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 2S: Ex. SWM Facility Drainage Area Runoff = 6.70 cfs @ 12.14 hrs, Volume= 0.482 af, Depth> 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 2 YR Rainfall=3.86" Area (ac) CN Description 1.040 98 Paved parking, HSG C 1.860 74 >75%Grass cover, Good, HSG C 2.900 83 Weighted Average 1.860 64.14% Pervious Area 1.040 35.86% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.7 200 0.0300 0.17 Sheet Flow, Grass: Dense n= 0.240 P2= 3.68" 1.8 150 0.0400 1.40 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 21.5 350 Total Subcatchment 2S: Ex. SWM Facility Drainage Area Hydrograph ®Runoff 7= 16.70cfs l Type II 24-hr ., 2 YR Rainfall_3.86" Runoff Area=2.900 ac 5 Runoff Volume=0.482 af 4 Runoff Depth>1.99" LL - - - Flow Length-350' Tc=21.5 min 2- CN=83 1— 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 19 Hydrograph for Subcatchment 2S: Ex. SWM Facility Drainage Area Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.13 0.00 0.00 18.60 3.60 1.94 0.17 3.30 0.15 0.00 0.00 18.90 3.61 1.95 0.16 3.60 0.16 0.00 0.00 19.20 3.63 1.97 0.15 3.90 0.18 0.00 0.00 19.50 3.65 1.98 0.14 4.20 0.20 0.00 0.00 19.80 3.66 2.00 0.14 4.50 0.21 0.00 0.00 4.80 0.23 0.00 0.00 5.10 0.25 0.00 0.00 5.40 0.27 0.00 0.00 5.70 0.29 0.00 0.00 6.00 0.31 0.00 0.00 6.30 0.33 0.00 0.00 6.60 0.35 0.00 0.00 6.90 0.37 0.00 0.00 7.20 0.40 0.00 0.00 7.50 0.42 0.00 0.00 7.80 0.45 0.00 0.00 8.10 0.47 0.00 0.01 8.40 0.50 0.00 0.01 8.70 0.53 0.01 0.02 9.00 0.57 0.01 0.03 9.30 0.60 0.02 0.05 9.60 0.64 0.02 0.06 9.90 0.68 0.03 0.07 10.20 0.73 0.04 0.09 10.50 0.79 0.06 0.13 10.80 0.85 0.08 0.17 11.10 0.94 0.11 0.23 11.40 1.05 0.15 0.33 11.70 1.37 0.31 0.62 12.00 2.56 1.10 4.26 12.30 2.75 1.25 4.50 12.60 2.87 1.34 1.58 12.90 2.96 1.41 0.85 13.20 3.02 1.47 0.62 13.50 3.08 1.51 0.52 13.80 3.14 1.56 0.44 14.10 3.18 1.59 0.38 14.40 3.22 1.63 0.34 14.70 3.26 1.66 0.32 15.00 3.29 1.69 0.30 15.30 3.33 1.71 0.28 15.60 3.36 1.74 0.26 15.90 3.39 1.76 0.24 16.20 3.41 1.79 0.23 16.50 3.44 1.81 0.21 16.80 3.46 1.83 0.21 17.10 3.49 1.85 0.20 17.40 3.51 1.87 0.19 17.70 3.53 1.89 0.19 18.00 3.56 1.90 0.18 18.30 3.58 1.92 0.17 Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 4S: Pre-Dev Disturbed Area Routed Runoff = 1.39 cfs @ 12.15 hrs, Volume= 0.100 af, Depth> 1.84" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 2 YR Rainfall=3.86" Area (ac) CN Description 0.460 74 >75%Grass cover, Good, HSG C 0.190 98 Paved parking, HSG C 0.650 81 Weighted Average 0.460 70.77% Pervious Area 0.190 29.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 4S: Pre-Dev Disturbed Area Routed Hydrograph ®Runoff 11.39 cfs I Type II 24-hr 2 YR Rainfall_3.86" Runoff Area_0650 ac 1- Runoff Volume=0.100 af _ Runoff Depth>1.84" Tc=21.5 min CN=810 3 4 5 6 7 8 9 10 —1Y- 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 21 Hydrograph for Subcatchment 4S: Pre-Dev Disturbed Area Routed Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.13 0.00 0.00 18.60 3.60 1.79 0.04 3.30 0.15 0.00 0.00 18.90 3.61 1.80 0.03 3.60 0.16 0.00 0.00 19.20 3.63 1.82 0.03 3.90 0.18 0.00 0.00 19.50 3.65 1.83 0.03 4.20 0.20 0.00 0.00 19.80 3.66 1.84 0.03 4.50 0.21 0.00 0.00 4.80 0.23 0.00 0.00 5.10 0.25 0.00 0.00 5.40 0.27 0.00 0.00 5.70 0.29 0.00 0.00 6.00 0.31 0.00 0.00 6.30 0.33 0.00 0.00 6.60 0.35 0.00 0.00 6.90 0.37 0.00 0.00 7.20 0.40 0.00 0.00 7.50 0.42 0.00 0.00 7.80 0.45 0.00 0.00 8.10 0.47 0.00 0.00 8.40 0.50 0.00 0.00 8.70 0.53 0.00 0.00 9.00 0.57 0.00 0.00 9.30 0.60 0.01 0.01 9.60 0.64 0.01 0.01 9.90 0.68 0.02 0.01 10.20 0.73 0.03 0.02 10.50 0.79 0.04 0.02 10.80 0.85 0.05 0.03 11.10 0.94 0.08 0.04 11.40 1.05 0.11 0.06 11.70 1.37 0.25 0.12 12.00 2.56 0.98 0.87 12.30 2.75 1.13 0.94 12.60 2.87 1.21 0.33 12.90 2.96 1.28 0.18 13.20 3.02 1.33 0.13 13.50 3.08 1.38 0.11 13.80 3.14 1.42 0.09 14.10 3.18 1.45 0.08 14.40 3.22 1.48 0.07 14.70 3.26 1.52 0.07 15.00 3.29 1.54 0.06 15.30 3.33 1.57 0.06 15.60 3.36 1.60 0.06 15.90 3.39 1.62 0.05 16.20 3.41 1.64 0.05 16.50 3.44 1.66 0.05 16.80 3.46 1.68 0.04 17.10 3.49 1.70 0.04 17.40 3.51 1.72 0.04 17.70 3.53 1.74 0.04 18.00 3.56 1.75 0.04 18.30 3.58 1.77 0.04 Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Runoff = 0.28 cfs @ 12.14 hrs, Volume= 0.020 af, Depth> 2.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type Il 24-hr 2 YR Rainfall=3.86" Area (ac) CN Description 0.040 74 >75%Grass cover, Good, HSG C 0.060 98 Paved parking, HSG C 0.100 88 Weighted Average 0.040 40.00% Pervious Area 0.060 60.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Hydrograph 0.3= ®Runoff 0.28. l oze cfs 0.26= Type II 24-hr 0.24- 2 YR Rainfall=3.86" 0.22 Runoff Area=0.100 ac Runoff Volume=0.020 af .... 0.18 ' 0.16 Runoff Depth>2.41" 3 = , 30.14 Tc=21.5 min 0.127. CN=88 0.1-- 0 08-: -0.08= 0.06- 0.04= 0.02 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 23 Hydrograph for Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.13 0.00 0.00 18.60 3.60 2.36 0.01 3.30 0.15 0.00 0.00 18.90 3.61 2.37 0.01 3.60 0.16 0.00 0.00 19.20 3.63 2.39 0.01 3.90 0.18 0.00 0.00 19.50 3.65 2.40 0.01 4.20 0.20 0.00 0.00 19.80 3.66 2.42 0.01 4.50 0.21 0.00 0.00 4.80 0.23 0.00 0.00 5.10 0.25 0.00 0.00 5.40 0.27 0.00 0.00 5.70 0.29 0.00 0.00 6.00 0.31 0.00 0.00 6.30 0.33 0.00 0.00 6.60 0.35 0.00 0.00 6.90 0.37 0.01 0.00 7.20 0.40 0.01 0.00 7.50 0.42 0.01 0.00 7.80 0.45 0.02 0.00 8.10 0.47 0.03 0.00 8.40 0.50 0.03 0.00 8.70 0.53 0.04 0.00 9.00 0.57 0.05 0.00 9.30 0.60 0.06 0.00 9.60 0.64 0.08 0.00 9.90 0.68 0.10 0.00 10.20 0.73 0.12 0.01 10.50 0.79 0.14 0.01 10.80 0.85 0.17 0.01 11.10 0.94 0.22 0.01 11.40 1.05 0.28 0.02 11.70 1.37 0.49 0.03 12.00 2.56 1.43 0.18 12.30 2.75 1.60 0.18 12.60 2.87 1.70 0.06 12.90 2.96 1.78 0.03 13.20 3.02 1.84 0.02 13.50 3.08 1.89 0.02 13.80 3.14 1.94 0.02 14.10 3.18 1.98 0.01 14.40 3.22 2.02 0.01 14.70 3.26 2.05 0.01 15.00 3.29 2.08 0.01 15.30 3.33 2.11 0.01 15.60 3.36 2.14 0.01 15.90 3.39 2.17 0.01 16.20 3.41 2.19 0.01 16.50 3.44 2.21 0.01 16.80 3.46 2.24 0.01 17.10 3.49 2.26 0.01 17.40 3.51 2.28 0.01 17.70 3.53 2.30 0.01 18.00 3.56 2.32 0.01 18.30 3.58 2.34 0.01 Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 24 Summary for Pond 3P: EX. SWM Faclity Inflow Area= 3.550 ac, 34.65% Impervious, Inflow Depth > 1.96" for 2 YR event Inflow = 8.09 cfs @ 12.14 hrs, Volume= 0.581 of Outflow = 7.75 cfs @ 12.19 hrs, Volume= 0.564 af, Atten=4%, Lag= 2.7 min Primary = 7.75 cfs @ 12.19 hrs, Volume= 0.564 of Routing by Stor-Ind method, Time Span= 3.00-20.01 hrs, dt= 0.03 hrs/3 Peak Elev= 393.70' @ 12.19 hrs Surf.Area=4,126 sf Storage= 2,249 cf Plug-Flow detention time= 19.9 min calculated for 0.564 af (97%of inflow) Center-of-Mass det. time= 9.1 min ( 803.1 - 794.0 ) Volume Invert Avail.Storage Storage Description #1 393.00' 4,931 cf Custom Stage Data (Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 393.00 1,900 0 0 393.50 3,839 1,435 1,435 394.00 4,540 2,095 3,530 394.30 4,800 1,401 4,931 Device Routing Invert Outlet Devices #1 Primary 389.91' 24.0" Round Culvert L= 53.0' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 389.91'/389.62' S= 0.0055 '/ Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 3.14 sf #2 Device 1 393.26' 24.0"x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=7.73 cfs @ 12.19 hrs HW=393.70' (Free Discharge) L.Culvert (Passes 7.73 cfs of 25.28 cfs potential flow) 2_Orifice/Grate (Weir Controls 7.73 cfs @ 2.18 fps) Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 25 Pond 3P: EX. SWM Faclity Hydrograph 9 ■Inflow 8.09cfs crs ®Primary 8J Inflow Area=3.550 af'780 Peak Elev_393.70' Storage=2,249 cf 6-' $ 5 3 - 0 LL 4- 2- 0 -2 1-' 7 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pond 3P: EX. SWM Faclity Stage-Discharge [M Primary II 394- c 0 m W 393 0 2 4 6 8 10 12 14 • • 16 • 18 Discharge (cfs) Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 26 Pond 3P: EX. SWM Faclity Stage-Area-Storage Surface/Horizontals wetted Area(sq-ft) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 0 Surface II ®Storage 394 m c 0 W 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 Storage(cubic-feet) Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 27 Hydrograph for Pond 3P: EX. SWM Faclity Time Inflow Storage Elevation Primary (hours) (cfs) (cubic-feet) (feet) (cfs) 3.00 0.00 0 393.00 0.00 3.60 0.00 0 393.00 0.00 4.20 0.00 0 393.00 0.00 4.80 0.00 0 393.00 0.00 5.40 0.00 0 393.00 0.00 6.00 0.00 0 393.00 0.00 6.60 0.00 0 393.00 0.00 7.20 0.00 0 393.00 0.00 7.80 0.00 1 393.00 0.00 8.40 0.01 19 393.01 0.00 9.00 0.04 74 393.04 0.00 9.60 0.07 190 393.09 0.00 10.20 0.11 374 393.17 0.00 10.80 0.20 682 393.28 0.07 11.40 0.40 795 393.32 0.35 12.00 5.13 1,570 393.54 3.77 12.60 1.91 1,275 393.46 2.30 13.20 0.75 930 393.36 0.81 13.80 0.54 861 393.34 0.56 14.40 0.42 820 393.32 0.43 15.00 0.37 802 393.32 0.37 15.60 0.32 787 393.31 0.33 16.20 0.27 771 393.31 0.28 16.80 0.25 761 393.31 0.25 17.40 0.23 755 393.30 0.24 18.00 0.22 749 393.30 0.22 18.60 0.20 742 393.30 0.20 19.20 0.18 735 393.30 0.19 19.80 0.17 728 393.29 0.17 Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 28 Stage-Discharge for Pond 3P: EX. SWM Faclity Elevation Primary Elevation Primary Elevation Primary (feet) (cfs) (feet) (cfs) (feet) (cfs) 393.00 0.00 393.52 3.47 394.04 17.01 393.01 0.00 393.53 3.67 394.05 17.12 393.02 0.00 393.54 3.88 394.06 17.23 393.03 0.00 393.55 4.09 394.07 17.33 393.04 0.00 393.56 4.30 394.08 17.44 393.05 0.00 393.57 4.52 394.09 17.55 393.06 0.00 393.58 4.74 394.10 17.65 393.07 0.00 393.59 4.96 394.11 17.76 393.08 0.00 393.60 5.19 394.12 17.86 393.09 0.00 393.61 5.42 394.13 17.96 393.10 0.00 393.62 5.65 394.14 18.07 393.11 0.00 393.63 5.89 394.15 18.17 393.12 0.00 393.64 6.13 394.16 18.27 393.13 0.00 393.65 6.37 394.17 18.37 393.14 0.00 393.66 6.62 394.18 18.47 393.15 0.00 393.67 6.87 394.19 18.57 393.16 0.00 393.68 7.12 394.20 18.67 393.17 0.00 393.69 7.38 394.21 18.77 393.18 0.00 393.70 7.64 394.22 18.87 393.19 0.00 393.71 7.90 394.23 18.97 393.20 0.00 393.72 8.16 394.24 19.07 393.21 0.00 393.73 8.43 394.25 19.16 393.22 0.00 393.74 8.70 394.26 19.26 393.23 0.00 393.75 8.97 394.27 19.36 393.24 0.00 393.76 9.25 394.28 19.45 393.25 0.00 393.77 9.53 394.29 19.55 393.26 0.00 393.78 9.81 394.30 19.64 393.27 0.03 393.79 10.09 393.28 0.07 393.80 10.38 393.29 0.14 393.81 10.67 393.30 0.21 393.82 10.96 393.31 0.29 393.83 11.26 393.32 0.38 393.84 11.56 393.33 0.48 393.85 11.86 393.34 0.59 393.86 12.16 393.35 0.71 393.87 12.46 393.36 0.83 393.88 12.77 393.37 0.95 393.89 13.08 393.38 1.09 393.90 13.39 393.39 1.23 393.91 13.71 393.40 1.37 393.92 14.03 393.41 1.52 393.93 14.35 393.42 1.67 393.94 14.67 393.43 1.83 393.95 14.99 393.44 2.00 393.96 15.32 393.45 2.17 393.97 15.65 393.46 2.34 393.98 15.98 393.47 2.52 393.99 16.32 393.48 2.70 394.00 16.57 393.49 2.89 394.01 16.68 393.50 3.08 394.02 16.79 393.51 3.27 394.03 16.90 Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 29 Stage-Area-Storage for Pond 3P: EX. SWM Faclity Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 393.00 1,900 0 394.04 4,575 3,712 393.02 1,978 39 394.06 4,592 3,803 393.04 2,055 79 394.08 4,609 3,895 393.06 2,133 121 394.10 4,627 3,988 393.08 2,210 164 394.12 4,644 4,081 393.10 2,288 209 394.14 4,661 4,174 393.12 2,365 256 394.16 4,679 4,267 393.14 2,443 304 394.18 4,696 4,361 393.16 2,520 354 394.20 4,713 4,455 393.18 2,598 405 394.22 4,731 4,549 393.20 2,676 458 394.24 4,748 4,644 393.22 2,753 512 394.26 4,765 4,739 393.24 2,831 568 394.28 4,783 4,835 393.26 2,908 625 394.30 4,800 4,931 393.28 2,986 684 393.30 3,063 745 393.32 3,141 807 393.34 3,219 870 393.36 3,296 935 393.38 3,374 1,002 393.40 3,451 1,070 393.42 3,529 1,140 393.44 3,606 1,211 393.46 3,684 1,284 393.48 3,761 1,359 393.50 3,839 1,435 393.52 3,867 1,512 393.54 3,895 1,589 393.56 3,923 1,668 393.58 3,951 1,746 393.60 3,979 1,826 393.62 4,007 1,906 393.64 4,035 1,986 393.66 4,063 2,067 393.68 4,091 2,148 393.70 4,119 2,231 393.72 4,147 2,313 393.74 4,175 2,396 393.76 4,204 2,480 393.78 4,232 2,565 393.80 4,260 2,650 393.82 4,288 2,735 393.84 4,316 2,821 393.86 4,344 2,908 393.88 4,372 2,995 393.90 4,400 3,083 393.92 4,428 3,171 393.94 4,456 3,260 393.96 4,484 3,349 393.98 4,512 3,439 394.00 4,540 3,530 394.02 4,557 3,620 Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 30 Summary for Link 6L: Point of Analysis Inflow Area= 3.650 ac, 35.34% Impervious, Inflow Depth > 1.92" for 2 YR event Inflow = 8.02 cfs @ 12.19 hrs, Volume= 0.585 of Primary = 8.02 cfs @ 12.19 hrs, Volume= 0.585 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 3.00-20.01 hrs, dt= 0.03 hrs Link 6L: Point of Analysis Hydrograph / •Inflow 8.02 cfs I ®Primary 8- Inflow Area3.650 a mrcfs 7- 6� .2 4J 3 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 2 YR Rainfall=3.86" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 31 Hydrograph for Link 6L: Point of Analysis Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 3.00 0.00 0.00 0.00 18.60 0.21 0.00 0.21 3.30 0.00 0.00 0.00 18.90 0.20 0.00 0.20 3.60 0.00 0.00 0.00 19.20 0.19 0.00 0.19 3.90 0.00 0.00 0.00 19.50 0.18 0.00 0.18 4.20 0.00 0.00 0.00 19.80 0.18 0.00 0.18 4.50 0.00 0.00 0.00 4.80 0.00 0.00 0.00 5.10 0.00 0.00 0.00 5.40 0.00 0.00 0.00 5.70 0.00 0.00 0.00 6.00 0.00 0.00 0.00 6.30 0.00 0.00 0.00 6.60 0.00 0.00 0.00 6.90 0.00 0.00 0.00 7.20 0.00 0.00 0.00 7.50 0.00 0.00 0.00 7.80 0.00 0.00 0.00 8.10 0.00 0.00 0.00 8.40 0.00 0.00 0.00 8.70 0.00 0.00 0.00 9.00 0.00 0.00 0.00 9.30 0.00 0.00 0.00 9.60 0.00 0.00 0.00 9.90 0.00 0.00 0.00 10.20 0.01 0.00 0.01 10.50 0.01 0.00 0.01 10.80 0.08 0.00 0.08 11.10 0.25 0.00 0.25 11.40 0.37 0.00 0.37 11.70 0.62 0.00 0.62 12.00 3.96 0.00 3.96 12.30 6.54 0.00 6.54 12.60 2.36 0.00 2.36 12.90 1.19 0.00 1.19 13.20 0.83 0.00 0.83 13.50 0.68 0.00 0.68 13.80 0.58 0.00 0.58 14.10 0.50 0.00 0.50 14.40 0.44 0.00 0.44 14.70 0.41 0.00 0.41 15.00 0.38 0.00 0.38 15.30 0.36 0.00 0.36 15.60 0.34 0.00 0.34 15.90 0.31 0.00 0.31 16.20 0.29 0.00 0.29 16.50 0.27 0.00 0.27 16.80 0.26 0.00 0.26 17.10 0.25 0.00 0.25 17.40 0.24 0.00 0.24 17.70 0.24 0.00 0.24 18.00 0.23 0.00 0.23 18.30 0.22 0.00 0.22 Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 2S: Ex. SWM Facility Drainage Area Runoff = 11.33 cfs @ 12.14 hrs, Volume= 0.826 af, Depth> 3.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 10 YR Rainfall=5.56" Area (ac) CN Description 1.040 98 Paved parking, HSG C 1.860 74 >75% Grass cover, Good, HSG C 2.900 83 Weighted Average 1.860 64.14% Pervious Area 1.040 35.86% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.7 200 0.0300 0.17 Sheet Flow, Grass: Dense n= 0.240 P2= 3.68" 1.8 150 0.0400 1.40 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 21.5 350 Total Subcatchment 2S: Ex. SWM Facility Drainage Area Hydrograph 12 a Runoff 111.33cfs 1 11_ Type II 24-hr lot 10 YR Rainfall=5.56" Runoff Area_2.900 ac 87' Runoff Volume=0.826 af Runoff Depth>3.42fi Flow Length=350' 53 Tc=21.5 min 4- CN=83 3: 2 1-' 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 33 Hydrograph for Subcatchment 2S: Ex. SWM Facility Drainage Area Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.19 0.00 0.00 18.60 5.18 3.34 0.26 3.30 0.21 0.00 0.00 18.90 5.21 3.36 0.25 3.60 0.24 0.00 0.00 19.20 5.23 3.38 0.23 3.90 0.26 0.00 0.00 19.50 5.26 3.41 0.22 4.20 0.28 0.00 0.00 19.80 5.28 3.43 0.21 4.50 0.31 0.00 0.00 4.80 0.33 0.00 0.00 5.10 0.36 0.00 0.00 5.40 0.39 0.00 0.00 5.70 0.42 0.00 0.00 6.00 0.44 0.00 0.00 6.30 0.48 0.00 0.01 6.60 0.51 0.00 0.02 6.90 0.54 0.01 0.03 7.20 0.57 0.01 0.04 7.50 0.61 0.02 0.05 7.80 0.64 0.02 0.06 8.10 0.68 0.03 0.07 8.40 0.72 0.04 0.08 8.70 0.77 0.05 0.10 9.00 0.82 0.07 0.13 9.30 0.87 0.08 0.15 9.60 0.92 0.10 0.17 9.90 0.98 0.13 0.20 10.20 1.05 0.15 0.24 10.50 1.13 0.19 0.30 10.80 1.23 0.24 0.38 11.10 1.35 0.30 0.50 11.40 1.51 0.38 0.69 11.70 1.97 0.67 1.22 12.00 3.69 2.02 7.50 12.30 3.96 2.26 7.46 12.60 4.13 2.40 2.56 12.90 4.26 2.51 1.35 13.20 4.36 2.60 0.98 13.50 4.44 2.67 0.82 13.80 4.52 2.74 0.70 14.10 4.58 2.80 0.60 14.40 4.64 2.85 0.54 14.70 4.69 2.90 0.50 15.00 4.75 2.94 0.47 15.30 4.79 2.99 0.44 15.60 4.84 3.03 0.41 15.90 4.88 3.07 0.38 16.20 4.92 3.10 0.35 16.50 4.96 3.13 0.33 16.80 4.99 3.17 0.32 17.10 5.03 3.20 0.31 17.40 5.06 3.23 0.30 17.70 5.09 3.26 0.29 18.00 5.12 3.28 0.28 18.30 5.15 3.31 0.27 Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment 4S: Pre-Dev Disturbed Area Routed Runoff = 2.41 cfs @ 12.14 hrs, Volume= 0.175 af, Depth> 3.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 10 YR Rainfall=5.56" Area (ac) CN Description 0.460 74 >75%Grass cover, Good, HSG C 0.190 98 Paved parking, HSG C 0.650 81 Weighted Average 0.460 70.77% Pervious Area 0.190 29.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 4S: Pre-Dev Disturbed Area Routed Hydrograph ®Runoff 12.41 cfs l Type II 24-hr 10 YR Rainfall:Z.56 2- Runoff Area=0.650 ac Runoff Volume_0.175 af Runoff Depth>3.23" LL Tc=21.5 min 1- CN=81 o �. �:, T,n , m � 3 •4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type /1 24-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 35 Hydrograph for Subcatchment 4S: Pre-Dev Disturbed Area Routed Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.19 0.00 0.00 18.60 5.18 3.14 0.06 3.30 0.21 0.00 0.00 18.90 5.21 3.17 0.05 3.60 0.24 0.00 0.00 19.20 5.23 3.19 0.05 3.90 0.26 0.00 0.00 19.50 5.26 3.21 0.05 4.20 0.28 0.00 0.00 19.80 5.28 3.23 0.05 4.50 0.31 0.00 0.00 4.80 0.33 0.00 0.00 5.10 0.36 0.00 0.00 5.40 0.39 0.00 0.00 5.70 0.42 0.00 0.00 6.00 0.44 0.00 0.00 6.30 0.48 0.00 0.00 6.60 0.51 0.00 0.00 6.90 0.54 0.00 0.00 7.20 0.57 0.00 0.00 7.50 0.61 0.01 0.01 7.80 0.64 0.01 0.01 8.10 0.68 0.02 0.01 8.40 0.72 0.02 0.01 8.70 0.77 0.03 0.02 9.00 0.82 0.05 0.02 9.30 0.87 0.06 0.03 9.60 0.92 0.07 0.03 9.90 0.98 0.09 0.04 10.20 1.05 0.12 0.05 10.50 1.13 0.15 0.06 10.80 1.23 0.19 0.07 11.10 1.35 0.24 0.10 11.40 1.51 0.32 0.14 11.70 1.97 0.59 0.25 12.00 3.69 1.86 1.58 12.30 3.96 2.09 1.60 12.60 4.13 2.23 0.55 12.90 4.26 2.34 0.29 13.20 4.36 2.42 0.21 13.50 4.44 2.50 0.18 13.80 4.52 2.56 0.15 14.10 4.58 2.62 0.13 14.40 4.64 2.67 0.12 14.70 4.69 2.72 0.11 15.00 4.75 2.76 0.10 15.30 4.79 2.80 0.10 15.60 4.84 2.84 0.09 15.90 4.88 2.88 0.08 16.20 4.92 2.91 0.08 16.50 4.96 2.95 0.07 16.80 4.99 2.98 0.07 17.10 5.03 3.01 0.07 17.40 5.06 3.04 0.07 17.70 5.09 3.07 0.06 18.00 5.12 3.09 0.06 18.30 5.15 3.12 0.06 Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Runoff = 0.44 cfs @ 12.14 hrs, Volume= 0.033 af, Depth> 3.93" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 3.00-20.01 hrs, dt=0.03 hrs Type II 24-hr 10 YR Rainfall=5.56" Area (ac) CN Description 0.040 74 >75% Grass cover, Good, HSG C 0.060 98 Paved parking, HSG C 0.100 88 Weighted Average 0.040 40.00% Pervious Area 0.060 60.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Hydrograph 0.48: ®Runoff 0.46; 0.44: 044cfs I 0.42_ Type II 24-hr 044: 10 YR Rainfall-=5.56" 0.0336 8` . 0.34 Runoff Area=0.100 ac 0.32-' >„ 0.3_ Runoff Volume=0.033 af 0. 0.22866' Runoff Depth>3.93" 0.24 0 0.22: - Tc21.5 min 0.2, 0.18'" CN=88 0.16' 0.14' 0.12 0.1= 0.08= 0.06:" 0.04 0 02 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 37 Hydrograph for Subcatchment 5S: Pre-Dev Disturbed Area Unrouted Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 3.00 0.19 0.00 0.00 18.60 5.18 3.84 0.01 3.30 0.21 0.00 0.00 18.90 5.21 3.86 0.01 3.60 0.24 0.00 0.00 19.20 5.23 3.89 0.01 3.90 0.26 0.00 0.00 19.50 5.26 3.91 0.01 4.20 0.28 0.00 0.00 19.80 5.28 3.93 0.01 4.50 0.31 0.00 0.00 4.80 0.33 0.00 0.00 5.10 0.36 0.01 0.00 5.40 0.39 0.01 0.00 5.70 0.42 0.01 0.00 6.00 0.44 0.02 0.00 6.30 0.48 0.03 0.00 6.60 0.51 0.03 0.00 6.90 0.54 0.04 0.00 7.20 0.57 0.05 0.00 7.50 0.61 0.07 0.00 7.80 0.64 0.08 0.00 8.10 0.68 0.09 0.00 8.40 0.72 0.11 0.01 8.70 0.77 0.13 0.01 9.00 0.82 0.16 0.01 9.30 0.87 0.18 0.01 9.60 0.92 0.21 0.01 9.90 0.98 0.24 0.01 10.20 1.05 0.28 0.01 10.50 1.13 0.33 0.01 10.80 1.23 0.40 0.02 11.10 1.35 0.47 0.02 11.40 1.51 0.59 0.03 11.70 1.97 0.94 0.05 12.00 3.69 2.44 0.30 12.30 3.96 2.70 0.28 12.60 4.13 2.85 0.10 12.90 4.26 2.97 0.05 13.20 4.36 3.06 0.04 13.50 4.44 3.14 0.03 13.80 4.52 3.21 0.03 14.10 4.58 3.27 0.02 14.40 4.64 3.33 0.02 14.70 4.69 3.38 0.02 15.00 4.75 3.43 0.02 15.30 4.79 3.47 0.02 15.60 4.84 3.52 0.01 15.90 4.88 3.55 0.01 16.20 4.92 3.59 0.01 16.50 4.96 3.63 0.01 16.80 4.99 3.66 0.01 17.10 5.03 3.69 0.01 17.40 5.06 3.72 0.01 17.70 5.09 3.75 0.01 18.00 5.12 3.78 0.01 18.30 5.15 3.81 0.01 Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 38 Summary for Pond 3P: EX. SWM Faclity Inflow Area= 3.550 ac, 34.65% Impervious, Inflow Depth > 3.38" for 10 YR event Inflow = 13.74 cfs @ 12.14 hrs, Volume= 1.001 af Outflow = 13.29 cfs @ 12.18 hrs, Volume= 0.984 af, Atten= 3%, Lag=2.3 min Primary = 13.29 cfs @ 12.18 hrs, Volume= 0.984 of Routing by Stor-Ind method, Time Span= 3.00-20.01 hrs, dt= 0.03 hrs/3 Peak Elev= 393.90' @ 12.18 hrs Surf.Area=4,395 sf Storage= 3,067 cf Plug-Flow detention time= 14.8 min calculated for 0.982 of (98%of inflow) Center-of-Mass det. time= 8.0 min ( 790.0 - 781.9 ) Volume Invert Avail.Storage Storage Description #1 393.00' 4,931 cf Custom Stage Data (Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 393.00 1,900 0 0 393.50 3,839 1,435 1,435 394.00 4,540 2,095 3,530 394.30 4,800 1,401 4,931 Device Routing Invert Outlet Devices #1 Primary 389.91' 24.0" Round Culvert L= 53.0' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 389.91'/389.62' S= 0.0055 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 3.14 sf #2 Device 1 393.26' 24.0"x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=13.28 cfs @ 12.18 hrs HW=393.90' (Free Discharge) L�Culvert (Passes 13.28 cfs of 26.14 cfs potential flow) 2=Orifice/Grate (Weir Controls 13.28 cfs @ 2.61 fps) Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 39 Pond 3P: EX. SWM Faclity Hydrograph ■Inflow 15. ®Primary ,4- Inflow Area=3.550' aim 13= 12= Peak E ev=393.90' „- Sforage=3,Ob7cf v. 6 5.=:' 4- 3= 2= 1 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pond 3P: EX. SWM Faclity f Stage-Discharge 1.1)==i 394- 1 c O m la 393 � 1 • . ( , / 0 2 4 6 8 10 12 14 16 18 Discharge (cfs) Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 40 Pond 3P: EX. SWM Faclity Stage-Area-Storage Surface/Horizontal-Wetted Area(sq-ft) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 ®Surface ®Storage 394 Zv m c 0 m 393 . 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 Storage(cubic-feet) Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 41 Hydrograph for Pond 3P: EX. SWM Faclity Time Inflow Storage Elevation Primary (hours) (cfs) (cubic-feet) (feet) (cfs) 3.00 0.00 0 393.00 0.00 3.60 0.00 0 393.00 0.00 4.20 0.00 0 393.00 0.00 4.80 0.00 0 393.00 0.00 5.40 0.00 0 393.00 0.00 6.00 0.00 1 393.00 0.00 6.60 0.02 21 393.01 0.00 7.20 0.04 83 393.04 0.00 7.80 0.06 196 393.09 0.00 8.40 0.09 364 393.16 0.00 9.00 0.15 623 393.26 0.00 9.60 0.20 737 393.30 0.19 10.20 0.29 765 393.31 0.27 10.80 0.46 819 393.32 0.42 11.40 0.83 917 393.35 0.76 12.00 9.08 2,142 393.68 7.08 12.60 3.11 1,550 393.53 3.67 13.20 1.20 1,047 393.39 1.27 13.80 0.85 949 393.36 0.88 14.40 0.65 892 393.35 0.67 15.00 0.57 867 393.34 0.58 15.60 0.50 846 393.33 0.51 16.20 0.43 824 393.33 0.44 16.80 0.39 810 393.32 0.40 17.40 0.36 801 393.32 0.37 18.00 0.34 792 393.32 0.34 18.60 0.31 784 393.31 0.32 19.20 0.29 774 393.31 0.29 19.80 0.26 764 393.31 0.26 Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 42 Stage-Discharge for Pond 3P: EX. SWM Faclity Elevation Primary Elevation Primary Elevation Primary (feet) (cfs) (feet) (cfs) (feet) (cfs) 393.00 0.00 393.52 3.47 394.04 17.01 393.01 0.00 393.53 3.67 394.05 17.12 393.02 0.00 393.54 3.88 394.06 17.23 393.03 0.00 393.55 4.09 394.07 17.33 393.04 0.00 393.56 4.30 394.08 17.44 393.05 0.00 393.57 4.52 394.09 17.55 393.06 0.00 393.58 4.74 394.10 17.65 393.07 0.00 393.59 4.96 394.11 17.76 393.08 0.00 393.60 5.19 394.12 17.86 393.09 0.00 393.61 5.42 394.13 17.96 393.10 0.00 393.62 5.65 394.14 18.07 393.11 0.00 393.63 5.89 394.15 18.17 393.12 0.00 393.64 6.13 394.16 18.27 393.13 0.00 393.65 6.37 394.17 18.37 393.14 0.00 393.66 6.62 394.18 18.47 393.15 0.00 393.67 6.87 394.19 18.57 393.16 0.00 393.68 7.12 394.20 18.67 393.17 0.00 393.69 7.38 394.21 18.77 393.18 0.00 393.70 7.64 394.22 18.87 393.19 0.00 393.71 7.90 394.23 18.97 393.20 0.00 393.72 8.16 394.24 19.07 393.21 0.00 393.73 8.43 394.25 19.16 393.22 0.00 393.74 8.70 394.26 19.26 393.23 0.00 393.75 8.97 394.27 19.36 393.24 0.00 393.76 9.25 394.28 19.45 393.25 0.00 393.77 9.53 394.29 19.55 393.26 0.00 393.78 9.81 394.30 19.64 393.27 0.03 393.79 10.09 393.28 0.07 393.80 10.38 393.29 0.14 393.81 10.67 393.30 0.21 393.82 10.96 393.31 0.29 393.83 11.26 393.32 0.38 393.84 11.56 393.33 0.48 393.85 11.86 393.34 0.59 393.86 12.16 393.35 0.71 393.87 12.46 393.36 0.83 393.88 12.77 393.37 0.95 393.89 13.08 393.38 1.09 393.90 13.39 393.39 1.23 393.91 13.71 393.40 1.37 393.92 14.03 393.41 1.52 393.93 14.35 393.42 1.67 393.94 14.67 393.43 1.83 393.95 14.99 393.44 2.00 393.96 15.32 393.45 2.17 393.97 15.65 393.46 2.34 393.98 15.98 393.47 2.52 393.99 16.32 393.48 2.70 394.00 16.57 393.49 2.89 394.01 16.68 393.50 3.08 394.02 16.79 393.51 3.27 394.03 16.90 Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 43 Stage-Area-Storage for Pond 3P: EX. SWM Faclity Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 393.00 1,900 0 394.04 4,575 3,712 393.02 1,978 39 394.06 4,592 3,803 393.04 2,055 79 394.08 4,609 3,895 393.06 2,133 121 394.10 4,627 3,988 393.08 2,210 164 394.12 4,644 4,081 393.10 2,288 209 394.14 4,661 4,174 393.12 2,365 256 394.16 4,679 4,267 393.14 2,443 304 394.18 4,696 4,361 393.16 2,520 354 394.20 4,713 4,455 393.18 2,598 405 394.22 4,731 4,549 393.20 2,676 458 394.24 4,748 4,644 393.22 2,753 512 394.26 4,765 4,739 393.24 2,831 568 394.28 4,783 4,835 393.26 2,908 625 394.30 4,800 4,931 393.28 2,986 684 393.30 3,063 745 393.32 3,141 807 393.34 3,219 870 393.36 3,296 935 393.38 3,374 1,002 393.40 3,451 1,070 393.42 3,529 1,140 393.44 3,606 1,211 393.46 3,684 1,284 393.48 3,761 1,359 393.50 3,839 1,435 393.52 3,867 1,512 393.54 3,895 1,589 393.56 3,923 1,668 393.58 3,951 1,746 393.60 3,979 1,826 393.62 4,007 1,906 393.64 4,035 1,986 393.66 4,063 2,067 393.68 4,091 2,148 393.70 4,119 2,231 393.72 4,147 2,313 393.74 4,175 2,396 393.76 4,204 2,480 393.78 4,232 2,565 393.80 4,260 2,650 393.82 4,288 2,735 393.84 4,316 2,821 393.86 4,344 2,908 393.88 4,372 2,995 393.90 4,400 3,083 393.92 4,428 3,171 393.94 4,456 3,260 393.96 4,484 3,349 393.98 4,512 3,439 394.00 4,540 3,530 394.02 4,557 3,620 Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 44 Summary for Link 6L: Point of Analysis Inflow Area= 3.650 ac, 35.34% Impervious, Inflow Depth > 3.34" for 10 YR event Inflow = 13.71 cfs @ 12.18 hrs, Volume= 1.016 af Primary = 13.71 cfs @12.18 hrs, Volume= 1.016 af, Allen= 0%, Lag=0.0 min Primary outflow= Inflow, Time Span= 3.00-20.01 hrs, dt= 0.03 hrs Link 6L: Point of Analysis Hydrograph ■Inflow 157.- ® ®Primary 14; Inflow Area=3.650 a 13� 12 11� 10-? 9� 8J 3 2 7A >, u. 5 4= 2= 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pre Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 45 Hydrograph for Link 6L: Point of Analysis Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 3.00 0.00 0.00 0.00 18.60 0.33 0.00 0.33 3.30 0.00 0.00 0.00 18.90 0.31 0.00 0.31 3.60 0.00 0.00 0.00 19.20 0.30 0.00 0.30 3.90 0.00 0.00 0.00 19.50 0.28 0.00 0.28 4.20 0.00 0.00 0.00 19.80 0.27 0.00 0.27 4.50 0.00 0.00 0.00 4.80 0.00 0.00 0.00 5.10 0.00 0.00 0.00 5.40 0.00 0.00 0.00 5.70 0.00 0.00 0.00 6.00 0.00 0.00 0.00 6.30 0.00 0.00 0.00 6.60 0.00 0.00 0.00 6.90 0.00 0.00 0.00 7.20 0.00 0.00 0.00 7.50 0.00 0.00 0.00 7.80 0.00 0.00 0.00 8.10 0.00 0.00 0.00 8.40 0.01 0.00 0.01 8.70 0.01 0.00 0.01 9.00 0.01 0.00 0.01 9.30 0.15 0.00 0.15 9.60 0.20 0.00 0.20 9.90 0.23 0.00 0.23 10.20 0.28 0.00 0.28 10.50 0.35 0.00 0.35 10.80 0.44 0.00 0.44 11.10 0.58 0.00 0.58 11.40 0.79 0.00 0.79 11.70 1.27 0.00 1.27 12.00 7.38 0.00 7.38 12.30 10.80 0.00 10.80 12.60 3.76 0.00 3.76 12.90 1.88 0.00 1.88 13.20 1.31 0.00 1.31 13.50 1.06 0.00 1.06 13.80 0.90 0.00 0.90 14.10 0.78 0.00 0.78 14.40 0.69 0.00 0.69 14.70 0.64 0.00 0.64 15.00 0.60 0.00 0.60 15.30 0.56 0.00 0.56 15.60 0.53 0.00 0.53 15.90 0.49 0.00 0.49 16.20 0.45 0.00 0.45 16.50 0.42 0.00 0.42 16.80 0.41 0.00 0.41 17.10 0.39 0.00 0.39 17.40 0.38 0.00 0.38 17.70 0.37 0.00 0.37 18.00 0.35 0.00 0.35 18.30 0.34 0.00 0.34 411:. 0 Post-Dev Distu ed Post S M Facility Area Routed Drai gae Area /'>\ ( 4S ) Modified S M Faclity Post-Dev Disturbed 6L Area Unrouted Point of Analysis (Subca) Reach 'on. Routing Diagram for Post Prepared by Timmons Group, Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Post Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 2.230 74 >75% Grass cover, Good, HSG C (2S, 4S, 5S) 1.100 98 Paved parking, HSG C (2S, 4S) 0.320 98 Water Surface, HSG C (5S) 3.650 83 TOTAL AREA Post Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 3 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 3P 389.91 389.62 53.0 0.0055 0.011 24.0 0.0 0.0 2 3P 390.00 389.95 12.5 0.0040 0.011 15.0 0.0 0.0 Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 2S: Post SWM Facility Draingae Area Runoff = 4.56 cfs 12.15 hrs, Volume= 0.327 af, Depth> 1.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt=0.01 hrs Type II 24-hr 1 YR Rainfall=3.04" Area (ac) CN Description 1.040 98 Paved parking, HSG C 1.860 74 >75% Grass cover, Good, HSG C 2.900 83 Weighted Average 1.860 64.14% Pervious Area 1.040 35.86% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.7 200 0.0300 0.17 Sheet Flow, Grass: Dense n= 0.240 P2= 3.68" 1.8 150 0.0400 1.40 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 21.5 350 Total Subcatchment 2S: Post SWM Facility Draingae Area Hydrograph 5- ®Runoff 1 4.56 cfs I Type II 24-hr 4-y 1 YR Rainfall=3.04" Runoff Area=2.900 ac Runoff Volume=0.327 af 3- Runoff Depth>1.35" Flow Length=350' 2 Tc=21.5 min CN=83 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 5 Hydrograph for Subcatchment 2S: Post SWM Facility Draingae Area Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 0.60 0.02 0.05 0.20 0.01 0.00 0.00 10.60 0.64 0.02 0.06 0.40 0.01 0.00 0.00 10.80 0.67 0.03 0.08 0.60 0.02 0.00 0.00 11.00 0.71 0.04 0.11 0.80 0.03 0.00 0.00 11.20 0.76 0.05 0.14 1.00 0.03 0.00 0.00 11.40 0.83 0.07 0.18 1.20 0.04 0.00 0.00 11.60 0.93 0.11 0.26 1.40 0.05 0.00 0.00 11.80 1.31 0.27 0.68 1.60 0.05 0.00 0.00 12.00 2.02 0.71 2.79 1.80 0.06 0.00 0.00 12.20 2.12 0.78 4.31 2.00 0.07 0.00 0.00 12.40 2.20 0.84 2.06 2.20 0.07 0.00 0.00 12.60 2.26 0.88 1.12 2.40 0.08 0.00 0.00 12.80 2.31 0.91 0.71 2.60 0.09 0.00 0.00 13.00 2.35 0.94 0.54 2.80 0.10 0.00 0.00 13.20 2.38 0.97 0.45 3.00 0.10 0.00 0.00 13.40 2.41 0.99 0.39 3.20 0.11 0.00 0.00 13.60 2.44 1.01 0.35 3.40 0.12 0.00 0.00 13.80 2.47 1.03 0.32 3.60 0.13 0.00 0.00 14.00 2.49 1.05 0.29 3.80 0.14 0.00 0.00 14.20 2.51 1.07 0.27 4.00 0.15 0.00 0.00 14.40 2.54 1.08 0.25 4.20 0.15 0.00 0.00 14.60 2.56 1.10 0.24 4.40 0.16 0.00 0.00 14.80 2.58 1.11 0.23 4.60 0.17 0.00 0.00 15.00 2.59 1.13 0.22 4.80 0.18 0.00 0.00 15.20 2.61 1.14 0.21 5.00 0.19 0.00 0.00 15.40 2.63 1.15 0.20 5.20 0.20 0.00 0.00 15.60 2.65 1.17 0.19 5.40 0.21 0.00 0.00 15.80 2.66 1.18 0.18 5.60 0.22 0.00 0.00 16.00 2.68 1.19 0.17 5.80 0.23 0.00 0.00 16.20 2.69 1.20 0.16 6.00 0.24 0.00 0.00 16.40 2.70 1.21 0.16 6.20 0.25 0.00 0.00 16.60 2.72 1.22 0.15 6.40 0.27 0.00 0.00 16.80 2.73 1.23 0.15 6.60 0.28 0.00 0.00 17.00 2.74 1.24 0.15 6.80 0.29 0.00 0.00 17.20 2.75 1.25 0.14 7.00 0.30 0.00 0.00 17.40 2.77 1.26 0.14 7.20 0.31 0.00 0.00 17.60 2.78 1.27 0.14 7.40 0.33 0.00 0.00 17.80 2.79 1.28 0.13 7.60 0.34 0.00 0.00 18.00 2.80 1.29 0.13 7.80 0.35 0.00 0.00 18.20 2.81 1.30 0.13 8.00 0.36 0.00 0.00 18.40 2.82 1.30 0.12 8.20 0.38 0.00 0.00 18.60 2.83 1.31 0.12 8.40 0.39 0.00 0.00 18.80 2.84 1.32 0.12 8.60 0.41 0.00 0.00 19.00 2.85 1.33 0.11 8.80 0.43 0.00 0.00 19.20 2.86 1.33 0.11 9.00 0.45 0.00 0.00 19.40 2.87 1.34 0.11 9.20 0.47 0.00 0.01 19.60 2.88 1.35 0.10 9.40 0.49 0.00 0.01 19.80 2.89 1.36 0.10 9.60 0.51 0.00 0.02 20.00 2.89 1.36 0.10 9.80 0.53 0.01 0.02 10.00 0.55 0.01 0.03 10.20 0.58 0.01 0.04 Post Type 11 24-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 4S: Post-Dev Disturbed Area Unrouted Runoff = 0.20 cfs @ 12.14 hrs, Volume= 0.014 af, Depth> 1.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt=0.01 hrs Type II 24-hr 1 YR Rainfall=3.04" Area (ac) CN Description 0.040 74 >75%Grass cover, Good, HSG C 0.060 98 Paved parking, HSG C 0.100 88 Weighted Average 0.040 40.00% Pervious Area 0.060 60.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 4S: Post-Dev Disturbed Area Unrouted Hydrograph 0.22-� 0.21= ®Runoff 0.19; 0.2, I o.2o cfs I Type Il 24-h r ,- 0.18; 1 YR Rainfall-=3.04" 0.17: 0.,6= Runoff Area_0100 ac 0.157:- 0 14.' .150.14= Runoff Volume=0.014 af 0.13_ H 0.12! Runoff Depth>1.71" '� 0.11; LL 0.,3 Tc_21.5 min 0.09- 0.08 CN=88 0.07= 0.06 0.05= 0.04= 0.03 0.02 0.01 0' 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 sin 06538 ©2016 HydroCAD Software Solutions LLC Page 7 Hydrograph for Subcatchment 4S: Post-Dev Disturbed Area Unrouted Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 0.60 0.07 0.00 0.20 0.01 0.00 0.00 10.60 0.64 0.08 0.00 0.40 0.01 0.00 0.00 10.80 0.67 0.09 0.01 0.60 0.02 0.00 0.00 11.00 0.71 0.11 0.01 0.80 0.03 0.00 0.00 11.20 0.76 0.13 0.01 1.00 0.03 0.00 0.00 11.40 0.83 0.16 0.01 1.20 0.04 0.00 0.00 11.60 0.93 0.22 0.01 1.40 0.05 0.00 0.00 11.80 1.31 0.45 0.04 1.60 0.05 0.00 0.00 12.00 2.02 0.98 0.13 1.80 0.06 0.00 0.00 12.20 2.12 1.07 0.18 2.00 0.07 0.00 0.00 12.40 2.20 1.13 0.09 2.20 0.07 0.00 0.00 12.60 2.26 1.18 0.05 2.40 0.08 0.00 0.00 12.80 2.31 1.22 0.03 2.60 0.09 0.00 0.00 13.00 2.35 1.25 0.02 2.80 0.10 0.00 0.00 13.20 2.38 1.28 0.02 3.00 0.10 0.00 0.00 13.40 2.41 1.31 0.02 3.20 0.11 0.00 0.00 13.60 2.44 1.33 0.01 3.40 0.12 0.00 0.00 13.80 2.47 1.36 0.01 3.60 0.13 0.00 0.00 14.00 2.49 1.38 0.01 3.80 0.14 0.00 0.00 14.20 2.51 1.39 0.01 4.00 0.15 0.00 0.00 14.40 2.54 1.41 0.01 4.20 0.15 0.00 0.00 14.60 2.56 1.43 0.01 4.40 0.16 0.00 0.00 14.80 2.58 1.45 0.01 4.60 0.17 0.00 0.00 15.00 2.59 1.46 0.01 4.80 0.18 0.00 0.00 15.20 2.61 1.48 0.01 5.00 0.19 0.00 0.00 15.40 2.63 1.49 0.01 5.20 0.20 0.00 0.00 15.60 2.65 1.51 0.01 5.40 0.21 0.00 0.00 15.80 2.66 1.52 0.01 5.60 0.22 0.00 0.00 16.00 2.68 1.53 0.01 5.80 0.23 0.00 0.00 16.20 2.69 1.54 0.01 6.00 0.24 0.00 0.00 16.40 2.70 1.56 0.01 6.20 0.25 0.00 0.00 16.60 2.72 1.57 0.01 6.40 0.27 0.00 0.00 16.80 2.73 1.58 0.01 6.60 0.28 0.00 0.00 17.00 2.74 1.59 0.01 6.80 0.29 0.00 0.00 17.20 2.75 1.60 0.01 7.00 0.30 0.00 0.00 17.40 2.77 1.61 0.01 7.20 0.31 0.00 0.00 17.60 2.78 1.62 0.01 7.40 0.33 0.00 0.00 17.80 2.79 1.63 0.01 7.60 0.34 0.00 0.00 18.00 2.80 1.64 0.01 7.80 0.35 0.00 0.00 18.20 2.81 1.65 0.00 8.00 0.36 0.01 0.00 18.40 2.82 1.66 0.00 8.20 0.38 0.01 0.00 18.60 2.83 1.67 0.00 8.40 0.39 0.01 0.00 18.80 2.84 1.68 0.00 8.60 0.41 0.01 0.00 19.00 2.85 1.69 0.00 8.80 0.43 0.02 0.00 19.20 2.86 1.69 0.00 9.00 0.45 0.02 0.00 19.40 2.87 1.70 0.00 9.20 0.47 0.02 0.00 19.60 2.88 1.71 0.00 9.40 0.49 0.03 0.00 19.80 2.89 1.72 0.00 9.60 0.51 0.03 0.00 20.00 2.89 1.72 0.00 9.80 0.53 0.04 0.00 10.00 0.55 0.05 0.00 10.20 0.58 0.06 0.00 Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 5S: Post-Dev Disturbed Area Routed Runoff = 1.18 cfs @ 12.14 hrs, Volume= 0.085 af, Depth> 1.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs Type II 24-hr 1 YR Rainfall=3.04" Area (ac) CN Description 0.330 74 >75% Grass cover, Good, HSG C 0.320 98 Water Surface, HSG C 0.650 86 Weighted Average 0.330 50.77% Pervious Area 0.320 49.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 5S: Post-Dev Disturbed Area Routed Hydrograph H Runoff I iia�l Type II 24-hr 1 1 YR Rainfalk3.04" Runoff Area=0.650 ac - Runoff Volume=0.085 af Runoff Depth>1.56" LL Tc=21.5 min CN=86 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 9 Hydrograph for Subcatchment 5S: Post-Dev Disturbed Area Routed Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 0.60 0.04 0.02 0.20 0.01 0.00 0.00 10.60 0.64 0.05 0.02 0.40 0.01 0.00 0.00 10.80 0.67 0.06 0.03 0.60 0.02 0.00 0.00 11.00 0.71 0.07 0.04 0.80 0.03 0.00 0.00 11.20 0.76 0.09 0.04 1.00 0.03 0.00 0.00 11.40 0.83 0.12 0.06 1.20 0.04 0.00 0.00 11.60 0.93 0.16 0.08 1.40 0.05 0.00 0.00 11.80 1.31 0.37 0.20 1.60 0.05 0.00 0.00 12.00 2.02 0.86 0.75 1.80 0.06 0.00 0.00 12.20 2.12 0.94 1.11 2.00 0.07 0.00 0.00 12.40 2.20 1.01 0.52 2.20 0.07 0.00 0.00 12.60 2.26 1.05 0.28 2.40 0.08 0.00 0.00 12.80 2.31 1.09 0.18 2.60 0.09 0.00 0.00 13.00 2.35 1.12 0.13 2.80 0.10 0.00 0.00 13.20 2.38 1.15 0.11 3.00 0.10 0.00 0.00 13.40 2.41 1.17 0.10 3.20 0.11 0.00 0.00 13.60 2.44 1.20 0.09 3.40 0.12 0.00 0.00 13.80 2.47 1.22 0.08 3.60 0.13 0.00 0.00 14.00 2.49 1.24 0.07 3.80 0.14 0.00 0.00 14.20 2.51 1.26 0.06 4.00 0.15 0.00 0.00 14.40 2.54 1.27 0.06 4.20 0.15 0.00 0.00 14.60 2.56 1.29 0.06 4.40 0.16 0.00 0.00 14.80 2.58 1.31 0.06 4.60 0.17 0.00 0.00 15.00 2.59 1.32 0.05 4.80 0.18 0.00 0.00 15.20 2.61 1.34 0.05 5.00 0.19 0.00 0.00 15.40 2.63 1.35 0.05 5.20 0.20 0.00 0.00 15.60 2.65 1.36 0.05 5.40 0.21 0.00 0.00 15.80 2.66 1.38 0.04 5.60 0.22 0.00 0.00 16.00 2.68 1.39 0.04 5.80 0.23 0.00 0.00 16.20 2.69 1.40 0.04 6.00 0.24 0.00 0.00 16.40 2.70 1.41 0.04 6.20 0.25 0.00 0.00 16.60 2.72 1.42 0.04 6.40 0.27 0.00 0.00 16.80 2.73 1.43 0.04 6.60 0.28 0.00 0.00 17.00 2.74 1.44 0.04 6.80 0.29 0.00 0.00 17.20 2.75 1.45 0.03 7.00 0.30 0.00 0.00 17.40 2.77 1.46 0.03 7.20 0.31 0.00 0.00 17.60 2.78 1.47 0.03 7.40 0.33 0.00 0.00 17.80 2.79 1.48 0.03 7.60 0.34 0.00 0.00 18.00 2.80 1.49 0.03 7.80 0.35 0.00 0.00 18.20 2.81 1.50 0.03 8.00 0.36 0.00 0.00 18.40 2.82 1.51 0.03 8.20 0.38 0.00 0.00 18.60 2.83 1.52 0.03 8.40 0.39 0.00 0.00 18.80 2.84 1.53 0.03 8.60 0.41 0.00 0.00 19.00 2.85 1.54 0.03 8.80 0.43 0.01 0.00 19.20 2.86 1.54 0.03 9.00 0.45 0.01 0.01 19.40 2.87 1.55 0.03 9.20 0.47 0.01 0.01 19.60 2.88 1.56 0.03 9.40 0.49 0.01 0.01 19.80 2.89 1.57 0.02 9.60 0.51 0.02 0.01 20.00 2.89 1.57 0.02 9.80 0.53 0.02 0.01 10.00 0.55 0.03 0.01 10.20 0.58 0.03 0.02 Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 10 Summary for Pond 3P: Modified SWM Faclity Inflow Area = 3.550 ac, 38.31% Impervious, Inflow Depth > 1.39" for 1 YR event Inflow = 5.73 cfs @ 12.15 hrs, Volume= 0.411 of Outflow = 4.57 cfs @ 12.26 hrs, Volume= 0.404 af, Atten= 20%, Lag= 6.6 min Primary = 4.57 cfs @ 12.26 hrs, Volume= 0.404 of Routing by Stor-Ind method, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs/3 Peak Elev= 391.46' @ 12.26 hrs Surf.Area= 2,375 sf Storage= 2,897 cf Plug-Flow detention time= 19.5 min calculated for 0.403 of (98%of inflow) Center-of-Mass det. time= 12.5 min ( 812.1 - 799.6 ) Volume Invert Avail.Storage Storage Description #1 390.00' 12,566 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 390.00 1,609 0 0 391.00 2,115 1,862 1,862 392.00 2,678 2,397 4,259 393.00 3,297 2,988 7,246 394.00 4,540 3,919 11,165 394.30 4,800 1,401 12,566 Device Routing Invert Outlet Devices #1 Primary 389.91' 24.0" Round Culvert L= 53.0' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 389.91'/389.62' S= 0.0055 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight &clean, Flow Area= 3.14 sf #2 Device 1 392.50' 24.0"x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 390.00' 15.0" Round Culvert L= 12.5' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 390.00'/389.95' S= 0.0040 'P Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 1.23 sf Primary OutFlow Max=4.57 cfs @ 12.26 hrs HW=391.46' (Free Discharge) t-.. =Culvert (Passes 4.57 cfs of 9.04 cfs potential flow) 2_Orifice/Grate ( Controls 0.00 cfs) 3_Culvert (Barrel Controls 4.57 cfs @ 4.01 fps) Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 11 Pond 3P: Modified SWM Faclity Hydrograph • I5.73 crs I ®Primary Inflow Area=3.550 ac 5- Peak Elev_391 .46' - 1 4 57 cfs Storage=2,897 cf 4 0 S y 0 3� 2- 1- 0 1 2 3 4 5 6 7 8 9 10 11 1213 14 15 16 17 18 19 20 Time (hours) Pond 3P: Modified SWM Faclity Stage-Discharge ®Primary 394- 393- 392- 3914 93 392-391-r 0 21 4 6 8 10 12 14 16 18 20 22 24 26 Discharge (cfs) Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 12 Pond 3P: Modified SWM Faclity Stage-Area-Storage Surface/Horizontal-Wetted Area(sq-ft) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 lilrgitio 394- 393-' S _ m 1 392- m 391-r . , , 0 2,000 4,000 6,000 8,000 10,000 12,000 Storage(cubic-feet) Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 13 Hydrograph for Pond 3P: Modified SWM Faclity Time Inflow Storage Elevation Primary (hours) (cfs) (cubic-feet) (feet) (cfs) 0.00 0.00 0 390.00 0.00 0.50 0.00 0 390.00 0.00 1.00 0.00 0 390.00 0.00 1.50 0.00 0 390.00 0.00 2.00 0.00 0 390.00 0.00 2.50 0.00 0 390.00 0.00 3.00 0.00 0 390.00 0.00 3.50 0.00 0 390.00 0.00 4.00 0.00 0 390.00 0.00 4.50 0.00 0 390.00 0.00 5.00 0.00 0 390.00 0.00 5.50 0.00 0 390.00 0.00 6.00 0.00 0 390.00 0.00 6.50 0.00 0 390.00 0.00 7.00 0.00 0 390.00 0.00 7.50 0.00 0 390.00 0.00 8.00 0.00 1 390.00 0.00 8.50 0.00 4 390.00 0.00 9.00 0.01 11 390.01 0.00 9.50 0.02 37 390.02 0.00 10.00 0.04 86 390.05 0.01 10.50 0.08 157 390.10 0.03 11.00 0.14 253 390.15 0.08 11.50 0.28 391 390.23 0.18 12.00 3.54 1,378 390.76 1.65 12.50 1.85 2,042 391.08 2.97 13.00 0.67 969 390.55 0.92 13.50 0.46 712 390.42 0.54 14.00 0.36 607 390.36 0.41 14.50 0.30 538 390.32 0.33 15.00 0.27 502 390.30 0.29 15.50 0.24 473 390.28 0.26 16.00 0.22 445 390.27 0.23 16.50 0.19 418 390.25 0.21 17.00 0.18 401 390.24 0.19 17.50 0.17 388 390.23 0.18 18.00 0.16 376 390.23 0.17 18.50 0.15 364 390.22 0.16 19.00 0.14 352 390.21 0.15 19.50 0.13 339 390.20 0.14 20.00 0.12 325 390.20 0.13 Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 14 Stage-Discharge for Pond 3P: Modified SWM Faclity Elevation Primary Elevation Primary (feet) (cfs) (feet) (cfs) 390.00 0.00 392.60 9.13 390.05 0.01 392.65 9.93 390.10 0.03 392.70 10.85 390.15 0.08 392.75 11.88 390.20 0.13 392.80 13.01 390.25 0.21 392.85 14.23 390.30 0.29 392.90 15.53 390.35 0.39 392.95 16.91 390.40 0.50 393.00 18.36 390.45 0.63 393.05 19.87 390.50 0.76 393.10 21.45 390.55 0.91 393.15 22.20 390.60 1.07 393.20 22.56 390.65 1.23 393.25 22.92 390.70 1.41 393.30 23.26 390.75 1.59 393.35 23.61 390.80 1.78 393.40 23.87 390.85 1.98 393.45 24.11 390.90 2.18 393.50 24.34 390.95 2.39 393.55 24.58 391.00 2.61 393.60 24.81 391.05 2.82 393.65 25.04 391.10 3.04 393.70 25.27 391.15 3.26 393.75 25.49 391.20 3.48 393.80 25.72 391.25 3.70 393.85 25.94 391.30 3.92 393.90 26.16 391.35 4.13 393.95 26.37 391.40 4.33 394.00 26.59 391.45 4.53 394.05 26.80 391.50 4.72 394.10 27.02 391.55 4.89 394.15 27.23 391.60 5.03 394.20 27.44 391.65 5.14 394.25 27.65 391.70 5.33 394.30 27.85 391.75 5.59 391.80 5.84 391.85 6.07 391.90 6.30 391.95 6.52 392.00 6.74 392.05 6.95 392.10 7.15 392.15 7.30 392.20 7.42 392.25 7.53 392.30 7.65 392.35 7.76 392.40 7.87 392.45 7.98 392.50 8.09 392.55 8.49 Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 15 Stage-Area-Storage for Pond 3P: Modified SWM Faclity Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 390.00 1,609 0 392.60 3,049 5,977 390.05 1,634 81 392.65 3,080 6,130 390.10 1,660 163 392.70 3,111 6,285 390.15 1,685 247 392.75 3,142 6,441 390.20 1,710 332 392.80 3,173 6,599 390.25 1,736 418 392.85 3,204 6,758 390.30 1,761 505 392.90 3,235 6,919 390.35 1,786 594 392.95 3,266 7,082 390.40 1,811 684 393.00 3,297 7,246 390.45 1,837 775 393.05 3,359 7,412 390.50 1,862 868 393.10 3,421 7,582 390.55 1,887 961 393.15 3,483 7,755 390.60 1,913 1,056 393.20 3,546 7,930 390.65 1,938 1,153 393.25 3,608 8,109 390.70 1,963 1,250 393.30 3,670 8,291 390.75 1,989 1,349 393.35 3,732 8,476 390.80 2,014 1,449 393.40 3,794 8,664 390.85 2,039 1,550 393.45 3,856 8,856 390.90 2,064 1,653 393.50 3,919 9,050 390.95 2,090 1,757 393.55 3,981 9,247 391.00 2,115 1,862 393.60 4,043 9,448 391.05 2,143 1,968 393.65 4,105 9,652 391.10 2,171 2,076 393.70 4,167 9,858 391.15 2,199 2,186 393.75 4,229 10,068 391.20 2,228 2,296 393.80 4,291 10,281 391.25 2,256 2,408 393.85 4,354 10,497 391.30 2,284 2,522 393.90 4,416 10,717 391.35 2,312 2,637 393.95 4,478 10,939 391.40 2,340 2,753 394.00 4,540 11,165 391.45 2,368 2,871 394.05 4,583 11,393 391.50 2,397 2,990 394.10 4,627 11,623 391.55 2,425 3,110 394.15 4,670 11,855 391.60 2,453 3,232 394.20 4,713 12,090 391.65 2,481 3,356 394.25 4,757 12,327 391.70 2,509 3,480 394.30 4,800 12,566 391.75 2,537 3,607 391.80 2,565 3,734 391.85 2,594 3,863 391.90 2,622 3,994 391.95 2,650 4,125 392.00 2,678 4,259 392.05 2,709 4,393 392.10 2,740 4,529 392.15 2,771 4,667 392.20 2,802 4,806 392.25 2,833 4,947 392.30 2,864 5,090 392.35 2,895 5,234 392.40 2,926 5,379 392.45 2,957 5,526 392.50 2,988 5,675 392.55 3,018 5,825 Post Type II 24-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 16 Summary for Link 6L: Point of Analysis Inflow Area = 3.650 ac, 38.90% Impervious, Inflow Depth > 1.37" for 1 YR event Inflow = 4.73 cfs @ 12.25 hrs, Volume= 0.418 af Primary = 4.73 cfs @ 12.25 hrs, Volume= 0.418 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs Link 6L: Point of Analysis Hydrograph ■Inflow 4.7s cfs I ■Primary 5 Inflow Area=3.650 ac 1473cfg 4- in 3 U - LL 1-- 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 1 YR Rainfall=3.04" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 17 Hydrograph for Link 6L: Point of Analysis Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 10.40 0.03 0.00 0.03 0.20 0.00 0.00 0.00 10.60 0.04 0.00 0.04 0.40 0.00 0.00 0.00 10.80 0.06 0.00 0.06 0.60 0.00 0.00 0.00 11.00 0.09 0.00 0.09 0.80 0.00 0.00 0.00 11.20 0.12 0.00 0.12 1.00 0.00 0.00 0.00 11.40 0.16 0.00 0.16 1.20 0.00 0.00 0.00 11.60 0.23 0.00 0.23 1.40 0.00 0.00 0.00 11.80 0.43 0.00 0.43 1.60 0.00 0.00 0.00 12.00 1.78 0.00 1.78 1.80 0.00 0.00 0.00 12.20 4.58 0.00 4.58 2.00 0.00 0.00 0.00 12.40 3.92 0.00 3.92 2.20 0.00 0.00 0.00 12.60 2.30 0.00 2.30 2.40 0.00 0.00 0.00 12.80 1.38 0.00 1.38 2.60 0.00 0.00 0.00 13.00 0.95 0.00 0.95 2.80 0.00 0.00 0.00 13.20 0.72 0.00 0.72 3.00 0.00 0.00 0.00 13.40 0.60 0.00 0.60 3.20 0.00 0.00 0.00 13.60 0.52 0.00 0.52 3.40 0.00 0.00 0.00 13.80 0.46 0.00 0.46 3.60 0.00 0.00 0.00 14.00 0.42 0.00 0.42 3.80 0.00 0.00 0.00 14.20 0.38 0.00 0.38 4.00 0.00 0.00 0.00 14.40 0.35 0.00 0.35 4.20 0.00 0.00 0.00 14.60 0.33 0.00 0.33 4.40 0.00 0.00 0.00 14.80 0.31 0.00 0.31 4.60 0.00 0.00 0.00 15.00 0.30 0.00 0.30 4.80 0.00 0.00 0.00 15.20 0.29 0.00 0.29 5.00 0.00 0.00 0.00 15.40 0.27 0.00 0.27 5.20 0.00 0.00 0.00 15.60 0.26 0.00 0.26 5.40 0.00 0.00 0.00 15.80 0.25 0.00 0.25 5.60 0.00 0.00 0.00 16.00 0.24 0.00 0.24 5.80 0.00 0.00 0.00 16.20 0.23 0.00 0.23 6.00 0.00 0.00 0.00 16.40 0.22 0.00 0.22 6.20 0.00 0.00 0.00 16.60 0.21 0.00 0.21 6.40 0.00 0.00 0.00 16.80 0.20 0.00 0.20 6.60 0.00 0.00 0.00 17.00 0.20 0.00 0.20 6.80 0.00 0.00 0.00 17.20 0.19 0.00 0.19 7.00 0.00 0.00 0.00 17.40 0.19 0.00 0.19 7.20 0.00 0.00 0.00 17.60 0.18 0.00 0.18 7.40 0.00 0.00 0.00 17.80 0.18 0.00 0.18 7.60 0.00 0.00 0.00 18.00 0.17 0.00 0.17 7.80 0.00 0.00 0.00 18.20 0.17 0.00 0.17 8.00 0.00 0.00 0.00 18.40 0.17 0.00 0.17 8.20 0.00 0.00 0.00 18.60 0.16 0.00 0.16 8.40 0.00 0.00 0.00 18.80 0.16 0.00 0.16 8.60 0.00 0.00 0.00 19.00 0.15 0.00 0.15 8.80 0.00 0.00 0.00 19.20 0.15 0.00 0.15 9.00 0.00 0.00 0.00 19.40 0.15 0.00 0.15 9.20 0.00 0.00 0.00 19.60 0.14 0.00 0.14 9.40 0.00 0.00 0.00 19.80 0.14 0.00 0.14 9.60 0.01 0.00 0.01 20.00 0.13 0.00 0.13 9.80 0.01 0.00 0.01 10.00 0.01 0.00 0.01 10.20 0.02 0.00 0.02 Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 2S: Post SWM Facility Draingae Area Runoff = 11.33 cfs @ 12.14 hrs, Volume= 0.826 af, Depth> 3.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs Type II 24-hr 10 YR Rainfall=5.56" Area (ac) CN Description 1.040 98 Paved parking, HSG C 1.860 74 >75% Grass cover, Good, HSG C 2.900 83 Weighted Average 1.860 64.14% Pervious Area 1.040 35.86% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.7 200 0.0300 0.17 Sheet Flow, Grass: Dense n= 0.240 P2= 3.68" 1.8 150 0.0400 1.40 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 21.5 350 Total Subcatchment 2S: Post SWM Facility Draingae Area Hydrograph ®Runoff 12- iii33cfsI 11- Type 1124-h Ir 10= 10 YR Rainfall=5.56 9J Runoff Area=2.900 ac 8 Runoff Volume=0.826 of Runoff Depth>3.42" LL 6= Flow Length=350' 57- Tc=21.5 min 4- CN=83 3f 2� 1 0 �� (�� ..�, �. . . (. , ( .�, 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 19 Hydrograph for Subcatchment 2S: Post SWM Facility Draingae Area Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 1.11 0.18 0.28 0.20 0.01 0.00 0.00 10.60 1.16 0.20 0.33 0.40 0.02 0.00 0.00 10.80 1.23 0.24 0.38 0.60 0.03 0.00 0.00 11.00 1.31 0.27 0.46 0.80 0.05 0.00 0.00 11.20 1.40 0.32 0.55 1.00 0.06 0.00 0.00 11.40 1.51 0.38 0.69 1.20 0.07 0.00 0.00 11.60 1.71 0.50 0.90 1.40 0.08 0.00 0.00 11.80 2.40 0.98 2.15 1.60 0.10 0.00 0.00 12.00 3.69 2.02 7.50 1.80 0.11 0.00 0.00 12.20 3.88 2.19 10.55 2.00 0.12 0.00 0.00 12.40 4.03 2.31 4.87 2.20 0.14 0.00 0.00 12.60 4.13 2.40 2.56 2.40 0.15 0.00 0.00 12.80 4.22 2.48 1.59 2.60 0.16 0.00 0.00 13.00 4.29 2.54 1.19 2.80 0.18 0.00 0.00 13.20 4.36 2.60 0.98 3.00 0.19 0.00 0.00 13.40 4.42 2.65 0.86 3.20 0.21 0.00 0.00 13.60 4.47 2.70 0.77 3.40 0.22 0.00 0.00 13.80 4.52 2.74 0.70 3.60 0.24 0.00 0.00 14.00 4.56 2.78 0.63 3.80 0.25 0.00 0.00 14.20 4.60 2.81 0.58 4.00 0.27 0.00 0.00 14.40 4.64 2.85 0.54 4.20 0.28 0.00 0.00 14.60 4.68 2.88 0.51 4.40 0.30 0.00 0.00 14.80 4.71 2.91 0.49 4.60 0.32 0.00 0.00 15.00 4.75 2.94 0.47 4.80 0.33 0.00 0.00 15.20 4.78 2.97 0.45 5.00 0.35 0.00 0.00 15.40 4.81 3.00 0.43 5.20 0.37 0.00 0.00 15.60 4.84 3.03 0.41 5.40 0.39 0.00 0.00 15.80 4.87 3.05 0.39 5.60 0.41 0.00 0.00 16.00 4.89 3.08 0.37 5.80 0.43 0.00 0.00 16.20 4.92 3.10 0.35 6.00 0.44 0.00 0.00 16.40 4.94 3.12 0.34 6.20 0.47 0.00 0.01 16.60 4.97 3.14 0.33 6.40 0.49 0.00 0.01 16.80 4.99 3.17 0.32 6.60 0.51 0.00 0.02 17.00 5.01 3.19 0.31 6.80 0.53 0.01 0.02 17.20 5.04 3.21 0.31 7.00 0.55 0.01 0.03 17.40 5.06 3.23 0.30 7.20 0.57 0.01 0.04 17.60 5.08 3.25 0.29 7.40 0.60 0.02 0.04 17.80 5.10 3.27 0.29 7.60 0.62 0.02 0.05 18.00 5.12 3.28 0.28 7.80 0.64 0.02 0.06 18.20 5.14 3.30 0.27 8.00 0.67 0.03 0.06 18.40 5.16 3.32 0.26 8.20 0.69 0.03 0.07 18.60 5.18 3.34 0.26 8.40 0.72 0.04 0.08 18.80 5.20 3.35 0.25 8.60 0.75 0.05 0.09 19.00 5.21 3.37 0.24 8.80 0.78 0.06 0.11 19.20 5.23 3.38 0.23 9.00 0.82 0.07 0.13 19.40 5.25 3.40 0.23 9.20 0.85 0.08 0.15 19.60 5.26 3.41 0.22 9.40 0.89 0.09 0.16 19.80 5.28 3.43 0.21 9.60 0.92 0.10 0.17 20.00 5.29 3.44 0.21 9.80 0.96 0.12 0.19 10.00 1.01 0.13 0.21 10.20 1.05 0.15 0.24 Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 4S: Post-Dev Disturbed Area Unrouted Runoff = 0.44 cfs @ 12.14 hrs, Volume= 0.033 af, Depth> 3.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt=0.01 hrs Type II 24-hr 10 YR Rainfall=5.56" Area (ac) CN Description 0.040 74 >75%Grass cover, Good, HSG C 0.060 98 Paved parking, HSG C 0.100 88 Weighted Average 0.040 40.00% Pervious Area 0.060 60.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 4S: Post-Dev Disturbed Area Unrouted Hydrograph 0.48 ®Runoff 0.46= 0.44 cls I 00.4442::. Type 1124-h r 038- 10 YR Rainfat1k5,56" 00.36: 100 ac 4= Runoff Area-0. 0.32 0.3' Runoff Volume_0.033 af :w 0.28' 026A Runoff Depth>3.92" 0.24 LL 022= Tc_21.5 min 0.2 0.18 CN=88 0.16= 014= 0.12: 0.1= 0.08_ 0.06 0.04 0.02' 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 21 Hydrograph for Subcatchment 4S: Post-Dev Disturbed Area Unrouted Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 1.11 0.32 0.01 0.20 0.01 0.00 0.00 10.60 1.16 0.35 0.02 0.40 0.02 0.00 0.00 10.80 1.23 0.40 0.02 0.60 0.03 0.00 0.00 11.00 1.31 0.45 0.02 0.80 0.05 0.00 0.00 11.20 1.40 0.51 0.03 1.00 0.06 0.00 0.00 11.40 1.51 0.59 0.03 1.20 0.07 0.00 0.00 11.60 1.71 0.73 0.04 1.40 0.08 0.00 0.00 11.80 2.40 1.29 0.09 1.60 0.10 0.00 0.00 12.00 3.69 2.44 0.30 1.80 0.11 0.00 0.00 12.20 3.88 2.62 0.40 2.00 0.12 0.00 0.00 12.40 4.03 2.76 0.18 2.20 0.14 0.00 0.00 12.60 4.13 2.85 0.10 2.40 0.15 0.00 0.00 12.80 4.22 2.93 0.06 2.60 0.16 0.00 0.00 13.00 4.29 3.00 0.04 2.80 0.18 0.00 0.00 13.20 4.36 3.06 0.04 3.00 0.19 0.00 0.00 13.40 4.42 3.12 0.03 3.20 0.21 0.00 0.00 13.60 4.47 3.17 0.03 3.40 0.22 0.00 0.00 13.80 4.52 3.21 0.03 3.60 0.24 0.00 0.00 14.00 4.56 3.25 0.02 3.80 0.25 0.00 0.00 14.20 4.60 3.29 0.02 4.00 0.27 0.00 0.00 14.40 4.64 3.33 0.02 4.20 0.28 0.00 0.00 14.60 4.68 3.36 0.02 4.40 0.30 0.00 0.00 14.80 4.71 3.40 0.02 4.60 0.32 0.00 0.00 15.00 4.75 3.43 0.02 4.80 0.33 0.00 0.00 15.20 4.78 3.46 0.02 5.00 0.35 0.00 0.00 15.40 4.81 3.49 0.02 5.20 0.37 0.01 0.00 15.60 4.84 3.52 0.01 5.40 0.39 0.01 0.00 15.80 4.87 3.54 0.01 5.60 0.41 0.01 0.00 16.00 4.89 3.57 0.01 5.80 0.43 0.02 0.00 16.20 4.92 3.59 0.01 6.00 0.44 0.02 0.00 16.40 4.94 3.61 0.01 6.20 0.47 0.02 0.00 16.60 4.97 3.64 0.01 6.40 0.49 0.03 0.00 16.80 4.99 3.66 0.01 6.60 0.51 0.03 0.00 17.00 5.01 3.68 0.01 6.80 0.53 0.04 0.00 17.20 5.04 3.70 0.01 7.00 0.55 0.05 0.00 17.40 5.06 3.72 0.01 7.20 0.57 0.05 0.00 17.60 5.08 3.74 0.01 7.40 0.60 0.06 0.00 17.80 5.10 3.76 0.01 7.60 0.62 0.07 0.00 18.00 5.12 3.78 0.01 7.80 0.64 0.08 0.00 18.20 5.14 3.80 0.01 8.00 0.67 0.09 0.00 18.40 5.16 3.82 0.01 8.20 0.69 0.10 0.00 18.60 5.18 3.84 0.01 8.40 0.72 0.11 0.01 18.80 5.20 3.86 0.01 8.60 0.75 0.12 0.01 19.00 5.21 3.87 0.01 8.80 0.78 0.14 0.01 19.20 5.23 3.89 0.01 9.00 0.82 0.16 0.01 19.40 5.25 3.90 0.01 9.20 0.85 0.17 0.01 19.60 5.26 3.92 0.01 9.40 0.89 0.19 0.01 19.80 5.28 3.93 0.01 9.60 0.92 0.21 0.01 20.00 5.29 3.95 0.01 9.80 0.96 0.23 0.01 10.00 1.01 0.26 0.01 10.20 1.05 0.28 0.01 Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 5S: Post-Dev Disturbed Area Routed Runoff = 2.73 cfs @ 12.14 hrs, Volume= 0.201 af, Depth> 3.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt=0.01 hrs Type II 24-hr 10 YR Rainfall=5.56" Area (ac) CN Description 0.330 74 >75% Grass cover, Good, HSG C 0.320 98 Water Surface, HSG C 0.650 86 Weighted Average 0.330 50.77% Pervious Area 0.320 49.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 5S: Post-Dev Disturbed Area Routed Hydrograph 3- ®Runoff 1 2.73 cts I Type II 24-hr - 10 YR Rainfall_5.56" Runoff Area-0.650 ac 2-, Runoff Volume_0.201 af Runoff Depth>3.72" ° Tc=21.5 min CN=86 1- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 23 Hydrograph for Subcatchment 5S: Post-Dev Disturbed Area Routed Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 1.11 0.25 0.08 0.20 0.01 0.00 0.00 10.60 1.16 0.29 0.09 0.40 0.02 0.00 0.00 10.80 1.23 0.32 0.10 0.60 0.03 0.00 0.00 11.00 1.31 0.37 0.12 0.80 0.05 0.00 0.00 11.20 1.40 0.43 0.15 1.00 0.06 0.00 0.00 11.40 1.51 0.50 0.18 1.20 0.07 0.00 0.00 11.60 1.71 0.63 0.24 1.40 0.08 0.00 0.00 11.80 2.40 1.16 0.55 1.60 0.10 0.00 0.00 12.00 3.69 2.26 1.84 1.80 0.11 0.00 0.00 12.20 3.88 2.44 2.53 2.00 0.12 0.00 0.00 12.40 4.03 2.58 1.16 2.20 0.14 0.00 0.00 12.60 4.13 2.67 0.60 2.40 0.15 0.00 0.00 12.80 4.22 2.75 0.37 2.60 0.16 0.00 0.00 13.00 4.29 2.81 0.28 2.80 0.18 0.00 0.00 13.20 4.36 2.87 0.23 3.00 0.19 0.00 0.00 13.40 4.42 2.93 0.20 3.20 0.21 0.00 0.00 13.60 4.47 2.97 0.18 3.40 0.22 0.00 0.00 13.80 4.52 3.02 0.16 3.60 0.24 0.00 0.00 14.00 4.56 3.06 0.15 3.80 0.25 0.00 0.00 14.20 4.60 3.10 0.13 4.00 0.27 0.00 0.00 14.40 4.64 3.13 0.12 4.20 0.28 0.00 0.00 14.60 4.68 3.17 0.12 4.40 0.30 0.00 0.00 14.80 4.71 3.20 0.11 4.60 0.32 0.00 0.00 15.00 4.75 3.23 0.11 4.80 0.33 0.00 0.00 15.20 4.78 3.26 0.10 5.00 0.35 0.00 0.00 15.40 4.81 3.29 0.10 5.20 0.37 0.00 0.00 15.60 4.84 3.32 0.10 5.40 0.39 0.00 0.00 15.80 4.87 3.34 0.09 5.60 0.41 0.00 0.00 16.00 4.89 3.37 0.09 5.80 0.43 0.01 0.00 16.20 4.92 3.39 0.08 6.00 0.44 0.01 0.01 16.40 4.94 3.41 0.08 6.20 0.47 0.01 0.01 16.60 4.97 3.44 0.08 6.40 0.49 0.01 0.01 16.80 4.99 3.46 0.07 6.60 0.51 0.02 0.01 17.00 5.01 3.48 0.07 6.80 0.53 0.02 0.01 17.20 5.04 3.50 0.07 7.00 0.55 0.03 0.01 17.40 5.06 3.52 0.07 7.20 0.57 0.03 0.02 17.60 5.08 3.54 0.07 7.40 0.60 0.04 0.02 17.80 5.10 3.56 0.07 7.60 0.62 0.04 0.02 18.00 5.12 3.58 0.06 7.80 0.64 0.05 0.02 18.20 5.14 3.60 0.06 8.00 0.67 0.06 0.02 18.40 5.16 3.62 0.06 8.20 0.69 0.07 0.02 18.60 5.18 3.63 0.06 8.40 0.72 0.08 0.03 18.80 5.20 3.65 0.06 8.60 0.75 0.09 0.03 19.00 5.21 3.67 0.06 8.80 0.78 0.10 0.03 19.20 5.23 3.68 0.05 9.00 0.82 0.11 0.04 19.40 5.25 3.70 0.05 9.20 0.85 0.13 0.04 19.60 5.26 3.71 0.05 9.40 0.89 0.14 0.05 19.80 5.28 3.73 0.05 9.60 0.92 0.16 0.05 20.00 5.29 3.74 0.05 9.80 0.96 0.18 0.05 10.00 1.01 0.20 0.06 10.20 1.05 0.22 0.07 Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 24 Summary for Pond 3P: Modified SWM Faclity Inflow Area= 3.550 ac, 38.31% Impervious, Inflow Depth > 3.47" for 10 YR event Inflow = 14.06 cfs @ 12.14 hrs, Volume= 1.027 of Outflow = 12.49 cfs @ 12.22 hrs, Volume= 1.016 af, Atten= 11%, Lag= 4.7 min Primary = 12.49 cfs @ 12.22 hrs, Volume= 1.016 of Routing by Stor-Ind method, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs/3 Peak Elev= 392.78' @ 12.22 hrs Surf.Area= 3,159 sf Storage= 6,527 cf Plug-Flow detention time= 15.5 min calculated for 1.016 of (99%of inflow) Center-of-Mass det. time= 11.1 min ( 790.7 - 779.6 ) Volume Invert Avail.Storage Storage Description #1 390.00' 12,566 cf Custom Stage Data (Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 390.00 1,609 0 0 391.00 2,115 1,862 1,862 392.00 2,678 2,397 4,259 393.00 3,297 2,988 7,246 394.00 4,540 3,919 11,165 394.30 4,800 1,401 12,566 Device Routing Invert Outlet Devices #1 Primary 389.91' 24.0" Round Culvert L= 53.0' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 389.91'/389.62' S= 0.0055 '/' Cc= 0.900 n=0.011 Concrete pipe, straight& clean, Flow Area= 3.14 sf #2 Device 1 392.50' 24.0"x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 390.00' 15.0" Round Culvert L= 12.5' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 390.00'/389.95' S= 0.0040 7' Cc= 0.900 n=0.011 Concrete pipe, straight & clean, Flow Area= 1.23 sf Primary OutFlow Max=12.48 cfs @ 12.22 hrs HW=392.78' (Free Discharge) t- =Culvert (Passes 12.48 cfs of 19.31 cfs potential flow) 2_Orifice/Grate (Weir Controls 3.81 cfs @ 1.72 fps) 3_Culvert (Inlet Controls 8.67 cfs @ 7.06 fps) Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 son/ 06538 ©2016 HydroCAD Software Solutions LLC Page 25 Pond 3P: Modified SWM Faclity Hydrograph I Inflow 15= l 14 06 crs ®Primary 14= Inflow Area=3.550 ac 13_ Peak MA _v=392 1,2.49 12= Storage-6,527 cf cfs 10. b 7� 6J 4_ 2-- 17 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pond 3P: Modified SWM Faclity Stage-Discharge p Primary 1 394- 393— -D c 0 392- > m - 391- 390 , . �. , . , , . . . . r. . , , , . . ( . ,� 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Discharge (cis) Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 26 Pond 3P: Modified SWM Faclity Stage-Area-Storage Surface/Horizontal,Wetted Area(sq-ft) 0 . 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 L®Surface ■Storage 394- 393-- _ 94 393 c - , 392- d 391 ' 0 2,000 4,000 6,000 8,000 10,000 12,000 Storage(cubic-feet) Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 27 Hydrograph for Pond 3P: Modified SWM Faclity Time Inflow Storage Elevation Primary (hours) (cfs) (cubic-feet) (feet) (cfs) 0.00 0.00 0 390.00 0.00 0.50 0.00 0 390.00 0.00 1.00 0.00 0 390.00 0.00 1.50 0.00 0 390.00 0.00 2.00 0.00 0 390.00 0.00 2.50 0.00 0 390.00 0.00 3.00 0.00 0 390.00 0.00 3.50 0.00 0 390.00 0.00 4.00 0.00 0 390.00 0.00 4.50 0.00 0 390.00 0.00 5.00 0.00 0 390.00 0.00 5.50 0.00 2 390.00 0.00 6.00 0.01 10390.01 0.00 6.50 0.02 36 1 390.02 0.00 7.00 0.04 88 390.05 0.01 7.50 0.06 151 390.09 0.03 8.00 0.09 210 390.13 0.05 8.50 0.12 262 390.16 0.09 9.00 0.17 325 390.20 0.13 9.50 0.22 392 390.24 0.18 10.00 0.27 447 390.27 0.23 10.50 0.38 534 390.32 0.32 11.00 0.58 670 390.39 0.49 11.50 1.00 899 390.52 0.81 12.00 9.34 3,117 391.55 4.89 12.50 4.25 4,683 392.16 7.31 13.00 1.47 1,576 390.86 2.03 13.50 1.01 1,093 390.62 1.13 14.00 0.78 924 390.53 0.85 14.50 0.64 815 390.47 0.69 15.00 0.58 758 390.44 0.61 15.50 0.52 713 390.42 0.54 16.00 0.46 667 390.39 0.48 16.50 0.41 623 390.37 0.43 17.00 0.39 598 390.35 0.40 17.50 0.36 579 390.34 0.37 18.00 0.34 560 390.33 0.35 18.50 0.32 540 390.32 0.33 19.00 0.30 520 390.31 0.31 19.50 0.27 500 390.30 0.29 20.00 0.25 478 390.28 0.26 Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 28 Stage-Discharge for Pond 3P: Modified SWM Faclity Elevation Primary Elevation Primary (feet) (cfs) (feet) (cfs) 390.00 0.00 392.60 9.13 390.05 0.01 392.65 9.93 390.10 0.03 392.70 10.85 390.15 0.08 392.75 11.88 390.20 0.13 392.80 13.01 390.25 0.21 392.85 14.23 390.30 0.29 392.90 15.53 390.35 0.39 392.95 16.91 390.40 0.50 393.00 18.36 390.45 0.63 393.05 19.87 390.50 0.76 393.10 21.45 390.55 0.91 393.15 22.20 390.60 1.07 393.20 22.56 390.65 1.23 393.25 22.92 390.70 1.41 393.30 23.26 390.75 1.59 393.35 23.61 390.80 1.78 393.40 23.87 390.85 1.98 393.45 24.11 390.90 2.18 393.50 24.34 390.95 2.39 393.55 24.58 391.00 2.61 393.60 24.81 391.05 2.82 393.65 25.04 391.10 3.04 393.70 25.27 391.15 3.26 393.75 25.49 391.20 3.48 393.80 25.72 391.25 3.70 393.85 25.94 391.30 3.92 393.90 26.16 391.35 4.13 393.95 26.37 391.40 4.33 394.00 26.59 391.45 4.53 394.05 26.80 391.50 4.72 394.10 27.02 391.55 4.89 394.15 27.23 391.60 5.03 394.20 27.44 391.65 5.14 394.25 27.65 391.70 5.33 394.30 27.85 391.75 5.59 391.80 5.84 391.85 6.07 391.90 6.30 391.95 6.52 392.00 6.74 392.05 6.95 392.10 7.15 392.15 7.30 392.20 7.42 392.25 7.53 392.30 7.65 392.35 7.76 392.40 7.87 392.45 7.98 392.50 8.09 392.55 8.49 Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 29 Stage-Area-Storage for Pond 3P: Modified SWM Faclity Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 390.00 1,609 0 392.60 3,049 5,977 390.05 1,634 81 392.65 3,080 6,130 390.10 1,660 163 392.70 3,111 6,285 390.15 1,685 247 392.75 3,142 6,441 390.20 1,710 332 392.80 3,173 6,599 390.25 1,736 418 392.85 3,204 6,758 390.30 1,761 505 392.90 3,235 6,919 390.35 1,786 594 392.95 3,266 7,082 390.40 1,811 684 393.00 3,297 7,246 390.45 1,837 775 393.05 3,359 7,412 390.50 1,862 868 393.10 3,421 7,582 390.55 1,887 961 393.15 3,483 7,755 390.60 1,913 1,056 393.20 3,546 7,930 390.65 1,938 1,153 393.25 3,608 8,109 390.70 1,963 1,250 393.30 3,670 8,291 390.75 1,989 1,349 393.35 3,732 8,476 390.80 2,014 1,449 393.40 3,794 8,664 390.85 2,039 1,550 393.45 3,856 8,856 390.90 2,064 1,653 393.50 3,919 9,050 390.95 2,090 1,757 393.55 3,981 9,247 391.00 2,115 1,862 393.60 4,043 9,448 391.05 2,143 1,968 393.65 4,105 9,652 391.10 2,171 2,076 393.70 4,167 9,858 391.15 2,199 2,186 393.75 4,229 10,068 391.20 2,228 2,296 393.80 4,291 10,281 391.25 2,256 2,408 393.85 4,354 10,497 391.30 2,284 2,522 393.90 4,416 10,717 391.35 2,312 2,637 393.95 4,478 10,939 391.40 2,340 2,753 394.00 4,540 11,165 391.45 2,368 2,871 394.05 4,583 11,393 391.50 2,397 2,990 394.10 4,627 11,623 391.55 2,425 3,110 394.15 4,670 11,855 391.60 2,453 3,232 394.20 4,713 12,090 391.65 2,481 3,356 394.25 4,757 12,327 391.70 2,509 3,480 394.30 4,800 12,566 391.75 2,537 3,607 391.80 2,565 3,734 391.85 2,594 3,863 391.90 2,622 3,994 391.95 2,650 4,125 392.00 2,678 4,259 392.05 2,709 4,393 392.10 2,740 4,529 392.15 2,771 4,667 392.20 2,802 4,806 392.25 2,833 4,947 392.30 2,864 5,090 392.35 2,895 5,234 392.40 2,926 5,379 392.45 2,957 5,526 392.50 2,988 5,675 392.55 3,018 5,825 Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 30 Summary for Link 6L: Point of Analysis Inflow Area= 3.650 ac, 38.90% Impervious, Inflow Depth > 3.45" for 10 YR event Inflow = 12.88 cfs @ 12.22 hrs, Volume= 1.049 of Primary = 12.88 cfs @ 12.22 hrs, Volume= 1.049 af, Atten= 0%, Lag=0.0 min Primary outflow= Inflow, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs Link 6L: Point of Analysis Hydrograph ■Inflow 14- 112.88 ors l ®Primary 13= Inflow Area=3.650 ac I12.88cf 12- 112 10= 9 N V 8J 3 72" O LL 6 5- 4= 3- 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 10 YR Rainfall=5.56" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 31 Hydrograph for Link 6L: Point of Analysis Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 10.40 0.31 0.00 0.31 0.20 0.00 0.00 0.00 10.60 0.37 0.00 0.37 0.40 0.00 0.00 0.00 10.80 0.43 0.00 0.43 0.60 0.00 0.00 0.00 11.00 0.51 0.00 0.51 0.80 0.00 0.00 0.00 11.20 0.61 0.00 0.61 1.00 0.00 0.00 0.00 11.40 0.75 0.00 0.75 1.20 0.00 0.00 0.00 11.60 0.96 0.00 0.96 1.40 0.00 0.00 0.00 11.80 1.67 0.00 1.67 1.60 0.00 0.00 0.00 12.00 5.19 0.00 5.19 1.80 0.00 0.00 0.00 12.20 12.74 0.00 12.74 2.00 0.00 0.00 0.00 12.40 8.25 0.00 8.25 2.20 0.00 0.00 0.00 12.60 5.77 0.00 5.77 2.40 0.00 0.00 0.00 12.80 3.40 0.00 3.40 2.60 0.00 0.00 0.00 13.00 2.08 0.00 2.08 2.80 0.00 0.00 0.00 13.20 1.52 0.00 1.52 3.00 0.00 0.00 0.00 13.40 1.25 0.00 1.25 3.20 0.00 0.00 0.00 13.60 1.09 0.00 1.09 3.40 0.00 0.00 0.00 13.80 0.97 0.00 0.97 3.60 0.00 0.00 0.00 14.00 0.88 0.00 0.88 3.80 0.00 0.00 0.00 14.20 0.80 0.00 0.80 4.00 0.00 0.00 0.00 14.40 0.73 0.00 0.73 4.20 0.00 0.00 0.00 14.60 0.69 0.00 0.69 4.40 0.00 0.00 0.00 14.80 0.65 0.00 0.65 4.60 0.00 0.00 0.00 15.00 0.62 0.00 0.62 4.80 0.00 0.00 0.00 15.20 0.60 0.00 0.60 5.00 0.00 0.00 0.00 15.40 0.57 0.00 0.57 5.20 0.00 0.00 0.00 15.60 0.55 0.00 0.55 5.40 0.00 0.00 0.00 15.80 0.52 0.00 0.52 5.60 0.00 0.00 0.00 16.00 0.50 0.00 0.50 5.80 0.00 0.00 0.00 16.20 0.47 0.00 0.47 6.00 0.00 0.00 0.00 16.40 0.45 0.00 0.45 6.20 0.00 0.00 0.00 16.60 0.43 0.00 0.43 6.40 0.00 0.00 0.00 16.80 0.42 0.00 0.42 6.60 0.01 0.00 0.01 17.00 0.41 0.00 0.41 6.80 0.01 0.00 0.01 17.20 0.40 0.00 0.40 7.00 0.01 0.00 0.01 17.40 0.39 0.00 0.39 7.20 0.02 0.00 0.02 17.60 0.38 0.00 0.38 7.40 0.03 0.00 0.03 17.80 0.37 0.00 0.37 7.60 0.04 0.00 0.04 18.00 0.36 0.00 0.36 7.80 0.05 0.00 0.05 18.20 0.35 0.00 0.35 8.00 0.06 0.00 0.06 18.40 0.34 0.00 0.34 8.20 0.07 0.00 0.07 18.60 0.34 0.00 0.34 8.40 0.08 0.00 0.08 18.80 0.33 0.00 0.33 8.60 0.10 0.00 0.10 19.00 0.32 0.00 0.32 8.80 0.12 0.00 0.12 19.20 0.31 0.00 0.31 9.00 0.14 0.00 0.14 19.40 0.30 0.00 0.30 9.20 0.16 0.00 0.16 19.60 0.29 0.00 0.29 9.40 0.18 0.00 0.18 19.80 0.28 0.00 0.28 9.60 0.20 0.00 0.20 20.00 0.27 0.00 0.27 9.80 0.22 0.00 0.22 10.00 0.24 0.00 0.24 10.20 0.27 0.00 0.27 Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 2S: Post SWM Facility Draingae Area Runoff = 21.21 cfs @ 12.14 hrs, Volume= 1.595 af, Depth> 6.60" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt=0.01 hrs Type II 24-hr 100 YR Rainfall=9.13" Area (ac) CN Description 1.040 98 Paved parking, HSG C 1.860 74 >75%Grass cover, Good, HSG C 2.900 83 Weighted Average 1.860 64.14% Pervious Area 1.040 35.86% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.7 200 0.0300 0.17 Sheet Flow, Grass: Dense n= 0.240 P2= 3.68" 1.8 150 0.0400 1.40 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 21.5 350 Total Subcatchment 2S: Post SWM Facility Draingae Area Hydrograph 23 ®Runoff 222_1 121 21 cls I 21 Type 1124-h r 20: 19; 10018 Rainfall=9.13" 183 16' Runoff Area_2.900 ac 15= „ 14- Runoff Volume_1595 of N i 13- Runoff Depth>6.60'. 127 loll- Flow Length=350' 9- Tc_21.5 min 8- 77' CN-83 6' 5- 4- ,- °' 3 2_ 1_ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 33 Hydrograph for Subcatchment 2S: Post SWM Facility Draingae Area Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 1.82 0.57 0.69 0.20 0.02 0.00 0.00 10.60 1.91 0.64 0.79 0.40 0.04 0.00 0.00 10.80 2.02 0.71 0.91 0.60 0.06 0.00 0.00 11.00 2.15 0.80 1.06 0.80 0.08 0.00 0.00 11.20 2.29 0.90 1.25 1.00 0.10 0.00 0.00 11.40 2.48 1.04 1.54 1.20 0.12 0.00 0.00 11.60 2.80 1.29 1.96 1.40 0.14 0.00 0.00 11.80 3.93 2.23 4.47 1.60 0.16 0.00 0.00 12.00 6.05 4.14 14.54 1.80 0.18 0.00 0.00 12.20 6.38 4.44 19.57 2.00 0.20 0.00 0.00 12.40 6.62 4.67 8.88 2.20 0.22 0.00 0.00 12.60 6.79 4.83 4.60 2.40 0.25 0.00 0.00 12.80 6.93 4.96 2.84 2.60 0.27 0.00 0.00 13.00 7.05 5.07 2.11 2.80 0.29 0.00 0.00 13.20 7.15 5.17 1.73 3.00 0.31 0.00 0.00 13.40 7.25 5.26 1.52 3.20 0.34 0.00 0.00 13.60 7.34 5.35 1.36 3.40 0.36 0.00 0.00 13.80 7.42 5.42 1.22 3.60 0.39 0.00 0.00 14.00 7.49 5.49 1.11 3.80 0.41 0.00 0.00 14.20 7.55 5.55 1.01 4.00 0.44 0.00 0.00 14.40 7.62 5.61 0.94 4.20 0.46 0.00 0.01 14.60 7.68 5.67 0.89 4.40 0.49 0.00 0.01 14.80 7.74 5.73 0.86 4.60 0.52 0.01 0.02 15.00 7.79 5.78 0.82 4.80 0.55 0.01 0.03 15.20 7.85 5.83 0.79 5.00 0.58 0.01 0.04 15.40 7.90 5.88 0.75 5.20 0.60 0.02 0.05 15.60 7.95 5.93 0.72 5.40 0.64 0.02 0.07 15.80 7.99 5.97 0.68 5.60 0.67 0.03 0.08 16.00 8.03 6.01 0.65 5.80 0.70 0.04 0.09 16.20 8.08 6.05 0.61 6.00 0.73 0.04 0.10 16.40 8.12 6.09 0.59 6.20 0.76 0.05 0.11 16.60 8.16 6.13 0.57 6.40 0.80 0.06 0.13 16.80 8.20 6.16 0.56 6.60 0.83 0.07 0.14 17.00 8.23 6.20 0.54 6.80 0.87 0.08 0.15 17.20 8.27 6.24 0.53 7.00 0.90 0.10 0.17 17.40 8.31 6.27 0.52 7.20 0.94 0.11 0.18 17.60 8.34 6.30 0.51 7.40 0.98 0.12 0.19 17.80 8.38 6.34 0.49 7.60 1.02 0.14 0.21 18.00 8.41 6.37 0.48 7.80 1.06 0.15 0.22 18.20 8.44 6.40 0.47 8.00 1.10 0.17 0.23 18.40 8.47 6.43 0.46 8.20 1.14 0.19 0.25 18.60 8.50 6.46 0.44 8.40 1.18 0.21 0.27 18.80 8.53 6.49 0.43 8.60 1.23 0.24 0.31 19.00 8.56 6.52 0.42 8.80 1.29 0.26 0.34 19.20 8.59 6.54 0.41 9.00 1.34 0.29 0.38 19.40 8.62 6.57 0.39 9.20 1.40 0.32 0.42 19.60 8.64 6.59 0.38 9.40 1.46 0.36 0.45 19.80 8.67 6.62 0.37 9.60 1.52 0.39 0.47 20.00 8.69 6.64 0.35 9.80 1.58 0.43 0.50 10.00 1.65 0.47 0.55 10.20 1.73 0.52 0.61 Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment 4S: Post-Dev Disturbed Area Unrouted Runoff = 0.78 cfs @ 12.13 hrs, Volume= 0.060 af, Depth> 7.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt=0.01 hrs Type II 24-hr 100 YR Rainfall=9.13" Area (ac) CN Description 0.040 74 >75%Grass cover, Good, HSG C 0.060 98 Paved parking, HSG C 0.100 88 Weighted Average 0.040 40.00% Pervious Area 0.060 60.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 4S: Post-Dev Disturbed Area Unrouted Hydrograph 0.85= ®Runoff 037" I o.7e cfs 0.75=' Type II 24-hr 077; 100 YR Rainfall=9.13" 0.65 0.6- Runoff Area=0.100 ac 0.55- Runoff Volume=0.060 af 0.5= z, 0.45 - Runoff Depth>7.21 LL 47. Tc=21.5 min 0.35 0.3= CN=88 0.25= 0.2 0.15` 0.1= 0.05= ,; 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 35 Hydrograph for Subcatchment 4S: Post-Dev Disturbed Area Unrouted Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 1.82 0.82 0.03 0.20 0.02 0.00 0.00 10.60 1.91 0.89 0.03 0.40 0.04 0.00 0.00 10.80 2.02 0.98 0.04 0.60 0.06 0.00 0.00 11.00 2.15 1.08 0.04 0.80 0.08 0.00 0.00 11.20 2.29 1.21 0.05 1.00 0.10 0.00 0.00 11.40 2.48 1.36 0.06 1.20 0.12 0.00 0.00 11.60 2.80 1.64 0.08 1.40 0.14 0.00 0.00 11.80 3.93 2.67 0.17 1.60 0.16 0.00 0.00 12.00 6.05 4.68 0.54 1.80 0.18 0.00 0.00 12.20 6.38 4.99 0.71 2.00 0.20 0.00 0.00 12.40 6.62 5.23 0.32 2.20 0.22 0.00 0.00 12.60 6.79 5.39 0.16 2.40 0.25 0.00 0.00 12.80 6.93 5.52 0.10 2.60 0.27 0.00 0.00 13.00 7.05 5.64 0.08 2.80 0.29 0.00 0.00 13.20 7.15 5.74 0.06 3.00 0.31 0.00 0.00 13.40 7.25 5.84 0.05 3.20 0.34 0.00 0.00 13.60 7.34 5.92 0.05 3.40 0.36 0.01 0.00 13.80 7.42 6.00 0.04 3.60 0.39 0.01 0.00 14.00 7.49 6.07 0.04 3.80 0.41 0.01 0.00 14.20 7.55 6.13 0.04 4.00 0.44 0.02 0.00 14.40 7.62 6.19 0.03 4.20 0.46 0.02 0.00 14.60 7.68 6.25 0.03 4.40 0.49 0.03 0.00 14.80 7.74 6.31 0.03 4.60 0.52 0.04 0.00 15.00 7.79 6.37 0.03 4.80 0.55 0.05 0.00 15.20 . 7.85 6.42 0.03 5.00 0.58 0.05 0.00 15.40 7.90 6.47 0.03 5.20 0.60 0.07 0.00 15.60 7.95 6.51 0.03 5.40 0.64 0.08 0.01 15.80 7.99 6.56 0.02 5.60 0.67 0.09 0.01 16.00 8.03 6.60 0.02 5.80 0.70 0.10 0.01 16.20 8.08 6.64 0.02 6.00 0.73 0.12 0.01 16.40 8.12 6.68 0.02 6.20 0.76 0.13 0.01 16.60 8.16 6.72 0.02 6.40 0.80 0.15 0.01 16.80 8.20 6.76 0.02 6.60 0.83 0.16 0.01 17.00 8.23 6.80 0.02 6.80 0.87 0.18 0.01 17.20 8.27 6.83 0.02 7.00 0.90 0.20 0.01 17.40 8.31 6.87 0.02 7.20 0.94 0.22 0.01 17.60 8.34 6.90 0.02 7.40 0.98 0.24 0.01 17.80 8.38 6.94 0.02 7.60 1.02 0.26 0.01 18.00 8.41 6.97 0.02 7.80 1.06 0.29 0.01 18.20 8.44 7.00 0.02 8.00 1.10 0.31 0.01 18.40 8.47 7.03 0.02 8.20 1.14 0.34 0.01 18.60 8.50 7.06 0.02 8.40 1.18 0.36 0.01 18.80 8.53 7.09 0.02 8.60 1.23 0.40 0.01 19.00 8.56 7.12 0.01 8.80 1.29 0.43 0.02 19.20 8.59 7.15 0.01 9.00 1.34 0.47 0.02 19.40 8.62 7.17 0.01 9.20 1.40 0.51 0.02 19.60 8.64 7.20 0.01 9.40 1.46 0.55 0.02 19.80 8.67 7.22 0.01 9.60 1.52 0.59 0.02 20.00 8.69 7.25 0.01 9.80 1.58 0.64 0.02 10.00 1.65 0.69 0.02 10.20 1.73 0.75 0.03 Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment 5S: Post-Dev Disturbed Area Routed Runoff = 4.93 cfs @ 12.13 hrs, Volume= 0.377 af, Depth> 6.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-20.00 hrs, dt=0.01 hrs Type II 24-hr 100 YR Rainfall=9.13" Area (ac) CN Description 0.330 74 >75%Grass cover, Good, HSG C 0.320 98 Water Surface, HSG C 0.650 86 Weighted Average 0.330 50.77% Pervious Area 0.320 49.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 Direct Entry, Subcatchment 5S: Post-Dev Disturbed Area Routed Hydrograph ®Runoff Type 1124-h r l493= . - 100 YR Rainfall=9.13" 4 Runoff Area=0.650 ac - Runoff Volume_0.377 af 3- Runoff Depth>6.96" Tc=21.5 min 2- CN=86 1-' 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 37 Hydrograph for Subcatchment 5S: Post-Dev Disturbed Area Routed Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 10.40 1.82 0.71 0.18 0.20 0.02 0.00 0.00 10.60 1.91 0.78 0.20 0.40 0.04 0.00 0.00 10.80 2.02 0.87 0.23 0.60 0.06 0.00 0.00 11.00 2.15 0.96 0.26 0.80 0.08 0.00 0.00 11.20 2.29 1.08 0.31 1.00 0.10 0.00 0.00 11.40 2.48 1.23 0.38 1.20 0.12 0.00 0.00 11.60 2.80 1.49 0.48 1.40 0.14 0.00 0.00 11.80 3.93 2.49 1.07 1.60 0.16 0.00 0.00 12.00 6.05 4.46 3.42 1.80 0.18 0.00 0.00 12.20 6.38 4.77 4.54 2.00 0.20 0.00 0.00 12.40 6.62 5.00 2.05 2.20 0.22 0.00 0.00 12.60 6.79 5.16 1.06 2.40 0.25 0.00 0.00 12.80 6.93 5.30 0.65 2.60 0.27 0.00 0.00 13.00 7.05 5.41 0.48 2.80 0.29 0.00 0.00 13.20 7.15 5.51 0.40 3.00 0.31 0.00 0.00 13.40 7.25 5.61 0.35 3.20 0.34 0.00 0.00 13.60 7.34 5.69 0.31 3.40 0.36 0.00 0.00 13.80 7.42 5.77 0.28 3.60 0.39 0.00 0.00 14.00 7.49 5.83 0.25 3.80 0.41 0.00 0.00 14.20 7.55 5.90 0.23 4.00 0.44 0.01 0.01 14.40 7.62 5.96 0.21 4.20 0.46 0.01 0.01 14.60 7.68 6.02 0.20 4.40 0.49 0.02 0.01 14.80 7.74 6.08 0.20 4.60 0.52 0.02 0.01 15.00 7.79 6.13 0.19 4.80 0.55 0.03 0.02 15.20 7.85 6.18 0.18 5.00 0.58 0.03 0.02 15.40 7.90 6.23 0.17 5.20 0.60 0.04 0.02 15.60 7.95 6.28 0.16 5.40 0.64 0.05 0.02 15.80 7.99 6.32 0.15 5.60 0.67 0.06 0.03 16.00 8.03 6.36 0.15 5.80 0.70 0.07 0.03 16.20 8.08 6.41 0.14 6.00 0.73 0.08 0.03 16.40 8.12 6.44 0.13 6.20 0.76 0.09 0.04 16.60 8.16 6.48 0.13 6.40 0.80 0.11 0.04 16.80 8.20 6.52 0.13 6.60 0.83 0.12 0.04 17.00 8.23 6.56 0.12 6.80 0.87 0.14 0.05 17.20 8.27 6.59 0.12 7.00 0.90 0.15 0.05 17.40 8.31 6.63 0.12 7.20 0.94 0.17 0.05 17.60 8.34 6.66 0.12 7.40 0.98 0.19 0.06 17.80 8.38 6.70 0.11 7.60 1.02 0.21 0.06 18.00 8.41 6.73 0.11 7.80 1.06 0.23 0.06 18.20 8.44 6.76 0.11 8.00 1.10 0.25 0.07 18.40 8.47 6.79 0.10 8.20 1.14 0.27 0.07 18.60 8.50 6.82 0.10 8.40 1.18 0.30 0.07 18.80 8.53 6.85 0.10 8.60 1.23 0.32 0.08 19.00 8.56 6.88 0.10 8.80 1.29 0.36 0.09 19.20 8.59 6.90 0.09 9.00 1.34 0.39 0.10 19.40 8.62 6.93 0.09 9.20 1.40 0.43 0.11 19.60 8.64 6.96 0.09 9.40 1.46 0.47 0.12 19.80 8.67 6.98 0.08 9.60 1.52 0.50 0.12 20.00 8.69 7.00 0.08 9.80 1.58 0.55 0.13 10.00 1.65 0.60 0.14 10.20 1.73 0.65 0.16 Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 38 Summary for Pond 3P: Modified SWM Faclity Inflow Area= 3.550 ac, 38.31% Impervious, Inflow Depth > 6.67" for 100 YR event Inflow = 26.15 cfs @ 12.14 hrs, Volume= 1.973 af Outflow = 23.84 cfs @ 12.20 hrs, Volume= 1.958 af, Atten= 9%, Lag= 4.1 min Primary = 23.84 cfs @ 12.20 hrs, Volume= 1.958 af Routing by Stor-Ind method, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs/3 Peak Elev= 393.39' @ 12.20 hrs Surf.Area= 3,787 sf Storage= 8,642 cf Plug-Flow detention time= 12.3 min calculated for 1.958 of (99%of inflow) Center-of-Mass det. time= 9.1 min ( 773.5 - 764.4 ) Volume Invert Avail.Storage Storage Description #1 390.00' 12,566 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 390.00 1,609 0 0 391.00 2,115 1,862 1,862 392.00 2,678 2,397 4,259 393.00 3,297 2,988 7,246 394.00 4,540 3,919 11,165 394.30 4,800 1,401 12,566 Device Routing Invert Outlet Devices #1 Primary 389.91' 24.0" Round Culvert L= 53.0' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 389.91'/389.62' S= 0.0055 '/ Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 3.14 sf #2 Device 1 392.50' 24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 390.00' 15.0" Round Culvert L= 12.5' RCP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 390.00'/389.95' S= 0.0040 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 1.23 sf Primary OutFlow Max=23.84 cfs @ 12.20 hrs HW=393.39' (Free Discharge) t- -Culvert (Inlet Controls 23.84 cfs @ 7.59 fps) 2_Orifice/Grate (Passes < 18.21 cfs potential flow) 3_Culvert (Passes < 9.83 cfs potential flow) Post Type U 24-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 39 Pond 3P: Modified SWM Faclity Hydrograph •Inflow 28� 12s.1scts l •Primary 26. Inflow Area=3.550 ac 24- Peak Elev_393.39' 123e4 es 22 20- #orage=8,642 cf 18� 'Si 16 J 14 IL 12� 10= 8- A 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pond 3P: Modified SWM Faclity Stage-Discharge ®Primary 394- 393— m c g 392- o 391- 39° . . , . . . - . • • , , , . . �. . . '1{C; . . ,T. . . . . . . . . . . . . . • ,' . . . , . , . . , . , . , (. . , ,� 0 2 4 6 8 12 14 16 18 20 22 24 26 Discharge (cfs) Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 40 Pond 3P: Modified SWM Faclity Stage-Area-Storage Surface/Horizontal:Wetted Area(sq-ft) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 1_ Surface II ■Storage 394- 393-' d c - 0 = 392- o > - d W - 391 390 , 0 2,000 4,000 6,000 8,000 10,000 12,000 Storage(cubic-feet) Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 41 Hydrograph for Pond 3P: Modified SWM Faclity Time Inflow Storage Elevation Primary (hours) (cfs) (cubic-feet) (feet) (cfs) 0.00 0.00 0 390.00 0.00 0.50 0.00 0 390.00 0.00 1.00 0.00 0 390.00 0.00 1.50 0.00 0 390.00 0.00 2.00 0.00 0 390.00 0.00 2.50 0.00 0 390.00 0.00 3.00 0.00 0 390.00 0.00 3.50 0.00 0 390.00 0.00 4.00 0.01 7 390.00 0.00 4.50 0.03 36 390.02 0.00 5.00 0.06 107 390.07 0.02 5.50 0.10 196 390.12 0.05 6.00 0.13 276 390.17 0.09 6.50 0.17 341 390.21 0.14 7.00 0.21 395 390.24 0.19 7.50 0.26 444 390.26 0.23 8.00 0.30 488 390.29 0.28 8.50 0.37 539 390.32 0.33 9.00 0.48 624 390.37 0.43 9.50 0.58 714 390.42 0.55 10.00 0.69 779 390.45 0.63 10.50 0.93 912 390.52 0.83 11.00 1.33 1,122 390.63 1.18 11.50 2.16 1,488 390.82 1.86 12.00 17.96 5,912 392.58 8.84 12.50 7.67 5,983 392.60 9.18 13.00 2.59 2,421 391.26 3.72 13.50 1.76 1,538 390.84 1.96 14.00 1.36 1,283 390.72 1.47 14.50 1.12 1,123 390.63 1.18 15.00 1.01 1,043 390.59 1.05 15.50 0.90 977 390.56 0.94 16.00 0.79 910 390.52 0.83 16.50 0.71 847 390.49 0.74 17.00 0.67 813 390.47 0.68 17.50 0.63 786 390.46 0.65 18.00 0.59 759 390.44 0.61 18.50 0.55 731 390.43 0.57 19.00 0.51 702 390.41 0.53 19.50 0.47 673 390.39 0.49 20.00 0.44 643 390.38 0.45 Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 42 Stage-Discharge for Pond 3P: Modified SWM Faclity Elevation Primary Elevation Primary (feet) (cfs) (feet) (cfs) 390.00 0.00 392.60 9.13 390.05 0.01 392.65 9.93 390.10 0.03 392.70 10.85 390.15 0.08 392.75 11.88 390.20 0.13 392.80 13.01 390.25 0.21 392.85 14.23 390.30 0.29 392.90 15.53 390.35 0.39 392.95 16.91 390.40 0.50 393.00 18.36 390.45 0.63 393.05 19.87 390.50 0.76 393.10 21.45 390.55 0.91 393.15 22.20 390.60 1.07 393.20 22.56 390.65 1.23 393.25 22.92 390.70 1.41 393.30 23.26 390.75 1.59 393.35 23.61 390.80 1.78 393.40 23.87 390.85 1.98 393.45 24.11 390.90 2.18 393.50 24.34 390.95 2.39 393.55 24.58 391.00 2.61 393.60 24.81 391.05 2.82 393.65 25.04 391.10 3.04 393.70 25.27 391.15 3.26 393.75 25.49 391.20 3.48 393.80 25.72 391.25 3.70 393.85 25.94 391.30 3.92 393.90 26.16 391.35 4.13 393.95 26.37 391.40 4.33 394.00 26.59 391.45 4.53 394.05 26.80 391.50 4.72 394.10 27.02 391.55 4.89 394.15 27.23 391.60 5.03 394.20 27.44 391.65 5.14 394.25 27.65 391.70 5.33 394.30 27.85 391.75 5.59 391.80 5.84 391.85 6.07 391.90 6.30 391.95 6.52 392.00 6.74 392.05 6.95 392.10 7.15 392.15 7.30 392.20 7.42 392.25 7.53 392.30 7.65 392.35 7.76 392.40 7.87 392.45 7.98 392.50 8.09 392.55 8.49 Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD®10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 43 Stage-Area-Storage for Pond 3P: Modified SWM Faclity Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 390.00 1,609 0 392.60 3,049 5,977 390.05 1,634 81 392.65 3,080 6,130 390.10 1,660 163 392.70 3,111 6,285 390.15 1,685 247 392.75 3,142 6,441 390.20 1,710 332 392.80 3,173 6,599 390.25 1,736 418 392.85 3,204 6,758 390.30 1,761 505 392.90 3,235 6,919 390.35 1,786 594 392.95 3,266 7,082 390.40 1,811 684 393.00 3,297 7,246 390.45 1,837 775 393.05 3,359 7,412 390.50 1,862 868 393.10 3,421 7,582 390.55 1,887 961 393.15 3,483 7,755 390.60 1,913 1,056 393.20 3,546 7,930 390.65 1,938 1,153 393.25 3,608 8,109 390.70 1,963 1,250 393.30 3,670 8,291 390.75 1,989 1,349 393.35 3,732 8,476 390.80 2,014 1,449 393.40 3,794 8,664 390.85 2,039 1,550 393.45 3,856 8,856 390.90 2,064 1,653 393.50 3,919 9,050 390.95 2,090 1,757 393.55 3,981 9,247 391.00 2,115 1,862 393.60 4,043 9,448 391.05 2,143 1,968 393.65 4,105 9,652 391.10 2,171 2,076 393.70 4,167 9,858 391.15 2,199 2,186 393.75 4,229 10,068 391.20 2,228 2,296 393.80 4,291 10,281 391.25 2,256 2,408 393.85 4,354 10,497 391.30 2,284 2,522 393.90 4,416 10,717 391.35 2,312 2,637 393.95 4,478 10,939 391.40 2,340 2,753 394.00 4,540 11,165 391.45 2,368 2,871 394.05 4,583 11,393 391.50 2,397 2,990 394.10 4,627 11,623 391.55 2,425 3,110 394.15 4,670 11,855 391.60 2,453 3,232 394.20 4,713 12,090 391.65 2,481 3,356 394.25 4,757 12,327 391.70 2,509 3,480 394.30 4,800 12,566 391.75 2,537 3,607 391.80 2,565 3,734 391.85 2,594 3,863 391.90 2,622 3,994 391.95 2,650 4,125 392.00 2,678 4,259 392.05 2,709 4,393 392.10 2,740 4,529 392.15 2,771 4,667 392.20 2,802 4,806 392.25 2,833 4,947 392.30 2,864 5,090 392.35 2,895 5,234 392.40 2,926 5,379 392.45 2,957 5,526 392.50 2,988 5,675 392.55 3,018 5,825 Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 44 Summary for Link 6L: Point of Analysis Inflow Area= 3.650 ac, 38.90% Impervious, Inflow Depth > 6.63" for 100 YR event Inflow = 24.55 cfs @ 12.20 hrs, Volume= 2.018 af Primary = 24.55 cfs @ 12.20 hrs, Volume= 2.018 af, Atten= 0%, Lag=0.0 min Primary outflow= Inflow, Time Span= 0.00-20.00 hrs, dt= 0.01 hrs Link 6L: Point of Analysis Hydrograph ■Inflow CUMLI®Primary 26=' Inflow Area-3.650 ac 24� 22- 20= 18-=- -a 8�m 16 ' 3 14- 0 LL 12- 10 8! 6- 0-- , , (. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Post Type 1124-hr 100 YR Rainfall=9.13" Prepared by Timmons Group Printed 4/3/2017 HydroCAD® 10.00-19 s/n 06538 ©2016 HydroCAD Software Solutions LLC Page 45 Hydrograph for Link 6L: Point of Analysis Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 10.40 0.81 0.00 0.81 0.20 0.00 0.00 0.00 10.60 0.92 0.00 0.92 0.40 0.00 0.00 0.00 10.80 1.06 0.00 1.06 0.60 0.00 0.00 0.00 11.00 1.23 0.00 1.23 0.80 0.00 0.00 0.00 11.20 1.44 0.00 1.44 1.00 0.00 0.00 0.00 11.40 1.73 0.00 1.73 1.20 0.00 0.00 0.00 11.60 2.16 0.00 2.16 1.40 0.00 0.00 0.00 11.80 3.61 0.00 3.61 1.60 0.00 0.00 0.00 12.00 9.38 0.00 9.38 1.80 0.00 0.00 0.00 12.20 24.55 0.00 24.55 2.00 0.00 0.00 0.00 12.40 13.25 0.00 13.25 2.20 0.00 0.00 0.00 12.60 8.03 0.00 8.03 2.40 0.00 0.00 0.00 12.80 5.64 0.00 5.64 2.60 0.00 0.00 0.00 13.00 3.80 0.00 3.80 2.80 0.00 0.00 0.00 13.20 2.68 0.00 2.68 3.00 0.00 0.00 0.00 13.40 2.17 0.00 2.17 3.20 0.00 0.00 0.00 13.60 1.88 0.00 1.88 3.40 0.00 0.00 0.00 13.80 1.67 0.00 1.67 3.60 0.00 0.00 0.00 14.00 1.51 0.00 1.51 3.80 0.00 0.00 0.00 14.20 1.37 0.00 1.37 4.00 0.00 0.00 0.00 14.40 1.26 0.00 1.26 4.20 0.00 0.00 0.00 14.60 1.18 0.00 1.18 4.40 0.00 0.00 0.00 14.80 1.12 0.00 1.12 4.60 0.01 0.00 0.01 15.00 1.08 0.00 1.08 4.80 0.01 0.00 0.01 15.20 1.03 0.00 1.03 5.00 0.02 0.00 0.02 15.40 0.99 0.00 0.99 5.20 0.03 0.00 0.03 15.60 0.94 0.00 0.94 5.40 0.05 0.00 0.05 15.80 0.90 0.00 0.90 5.60 0.06 0.00 0.06 16.00 0.85 0.00 0.85 5.80 0.08 0.00 0.08 16.20 0.81 0.00 0.81 6.00 0.10 0.00 0.10 16.40 0.77 0.00 0.77 6.20 0.12 0.00 0.12 16.60 0.74 0.00 0.74 6.40 0.14 0.00 0.14 16.80 0.72 0.00 0.72 6.60 0.16 0.00 0.16 17.00 0.70 0.00 0.70 6.80 0.18 0.00 0.18 17.20 0.69 0.00 0.69 7.00 0.20 0.00 0.20 17.40 0.67 0.00 0.67 7.20 0.21 0.00 0.21 17.60 0.66 0.00 0.66 7.40 0.23 0.00 0.23 17.80 0.64 0.00 0.64 7.60 0.25 0.00 0.25 18.00 0.62 0.00 0.62 7.80 0.27 0.00 0.27 18.20 0.61 0.00 0.61 8.00 0.29 0.00 0.29 18.40 0.59 0.00 0.59 8.20 0.30 0.00 0.30 18.60 0.58 0.00 0.58 8.40 0.33 0.00 0.33 18.80 0.56 0.00 0.56 8.60 0.36 0.00 0.36 19.00 0.54 0.00 0.54 8.80 0.40 0.00 0.40 19.20 0.53 0.00 0.53 9.00 0.45 0.00 0.45 19.40 0.51 0.00 0.51 9.20 0.50 0.00 0.50 19.60 0.50 0.00 0.50 9.40 0.55 0.00 0.55 19.80 0.48 0.00 0.48 9.60 0.58 0.00 0.58 20.00 0.46 0.00 0.46 9.80 0.61 0.00 0.61 10.00 0.66 0.00 0.66 10.20 0.72 0.00 0.72 DEQ Virginia Runoff Reduction Method Re-Development Compliance Spreadsheet -Version 3.0 U 2011 BMP Standards and Specifications L7 2013 Draft BMP Standards and Specifications Project Name: Scottsville Elementary Addtion CLEAR ALL _- -- data input cells - - '- Date: en constantvalues - linear Development Project? No calculation cells Site Information 1I 1 1 final results i ■ --_� - Post-Development Project(Treatment Volume and Loads) I -_-■ I Enter Total Disturbed Area(acres) 0.75 I- Check:_ -- BMP Desi,n.5,ed,cations List: 2013 Draft Stds&Specs Maximum reduction required: 10% Linear project? No - The site's net increase in impervious cover(acres)is: 0.13 Land cover areas entered correctly? ,/ Post-Development TP Load Reduction for Site(lb/yr): 0.30 Total disturbed area entered? ,/ Pre-ReDevelopment Land Cover (acres) II A Soils B Soils C Soils D Soils - •rotectedfoForest/Open epace s/o.en ,a e-u ftrrsed, _---®_--- .rotec[ed forest/o.en s.ace or reforested land 0'� ■ andsManaged Turf tucres)rftob disturbed,owed/ agra:ed for _--- ■ ards or other turf to be mowed/mana:ed __- 0.50 0.50 Impervious Cover(acres) 0.25 0.25 ■ ®ME--_ - ___ - Post-Development Land Cover (acres) -_-_ M A Soils B Soils C Soils D Soils Totals -- MI - Forest/Open Space(acres)--undisturbed, ---- .rotected forest/o.en s.ace or reforested land 0'00 _■ ManagedTurf(acres)-disturbed,graded for --- ■ aor other turf to bee mowed/mana;ed 0.37 037 impervious rvious Cover(acres) _- 0.38 0.38 --- ■ Area Check OK. OK. OK. OK. 0.75 --___ -_- 1111 Constants Runoff Coefficients Rv --_ -- Annual Rainfall(inches) 43 A Soils B Soils C Soils D Soils - -- Target Rainfall Event(inches) 1.00 -Forest/Open Space 0.02 0.03 0.04 0.05 - - Total Phosphorus(TP)EMC(mg/L) 0.26 Managed Turf 0.15 0.20 0.22 0.25 - - Total Nitrogen(TN)EMC(mg/L) 1.86 Impervious Cover 0.95 0.95 0.95 0.95 -_ Target TP Load(lb/acre/yr) 0.41 -- ---- IIII. - . 0.90 ---- -- - ---- Iillllllllllll■ -_ LAND COVER SUMMARY-- PRE-REDEVELOPMENT LAND COVER SUMMARY--POST DEVELOPMENT Land Cover Summary-Pre Land Cover Summary-Post(Final) Land Cover Summary-Post Land Cover Summary-Post Pre-ReDevelopment Listed Adjusted' Post ReDev.&New Impervious Post-ReDevelopment Post-Development New Impervious Forest/Open Space Forest/open Space °�` � r 3.04s Forest/Open Space Cover(acres) 0.00 0.00 0.00 0.00 Cover(acres) Cover(acres) Weighted Rv(forest) 0.00 0.00 Weighted Rv(forest) 0.00 Weighted Rv(forest) 0.00 S s 041 %Forest 0% 0% %Forest 0% %Forest 0% �"' Managed Turf Cover(acres) 0.50 0.37 Managed Turf Cover Managed Turf Cover �„, g 0.3/ 0.37 (acres) (acres) '�� rd`s; Ti .'t11:V4FMNtRi Weighted Rv(turf) 0.22 0.22 Weighted Rv(turf) 0.22 Walghted Rv(turf) 0 22 `_n K %Managed Turf 67% 60% %Managed Turf 49% %Managed Turf 60% "". ,7 Impervious Cover ReDev.Impervious New Impervious Cover Impervious Cover(acres) 0.25 0.25 0.38 0.25 Mil_ (acres) 0.13 (acres) Cover(acres) (,-t Rv(impervious) 0.95 0.95 Rv(im pervious) 0.95 Rv(impervious) 0.95 Rv(impervlous) 0.95 %Impervious 33% 40% %Im pervious 51% %Impervious 40% •Total ReDev.Site Area «, ^T Total Site Area(acres) 0.75 0.62 Final Site Area(acres) 0.75 0.62 (acres) 'fix Site Rv 0.46 0.51 Final Post Dev Site Rv 0.59 ReDev Site Rv 0 51 Treatment Volume and Nutrient Load Treatment Volume and Nutrient Load FFinal Post Post ReDevelopment Post Development Pre-ReDevelopment Treatment Volume Development (acre-ft) 0.0290 0.0266 treatment volume 0.0369 Treatment Volume 0.0266 treatment volume 0.0103 (acre ft) (acre-ft) (arm ft) Final Post Pre-ReDevelopment Treatment Volume 1,261 1,158 Development Post-ReDevelopment Post Development (cubic feet) treatment Vnlu me 1,606 Treatment Volume 1,158 Treatment Volume(cubic 448 (rrtnir feet) (cubic feet) feet) Pre-ReDevelopment TP Load Final Post Post-ReDevelopment 111 j Post-Development 7P 0.79 0.73 Development TP Load 1.01 Load DV) l 0.73' 0.28 (lb/yr) 3. i i Load(Ib/yr) (Ib/yr) 1 (Ib/yr)' I Pre-ReDevelopment TP Load per acre Final Post-Development TF Post R to e t TP (lb/acre/Yr) 1.06 1.17 Load per acre 1.35 L d oe•acre 'X/ # m (Ib/acro/ye) (lb/acre/yr) 999 Baseline TP Load(lb/yr) Max Reduction Required (Below Pre- (0.40Ibs/arn/yrooplied to pre-redevelopment area excluding pervious 0.25 land proposed for new impervious cover) ReDevelopment Load) 10% -----�-MIEN IIMIIMIN=.11111MIIM 1 4 `Adjusted Land Cover Summary: TP Load Reduction TP Load Reduction Pre ReDevelopment land cover minus pervious land cover(forest/open space or Required for managed turf)acreage proposed for new impervious cover. Redeveloped Area 0.07 Required for New 0.23 (Ib/yr) Impervious Area(Ib/yr) Adjusted total acreage is consistent with Post-ReDevelopment acreage(minus 1 acreage of new impervious cover). a IColumn 1.shows load reduction requriement for new impervious cover(based on new j development load limit,0.41 lbs/acre/year). `s Post-Development Requirement for Site Area TP Load Reduction Required(lb/yr) 0.30 Nitrogen Loads(Informational Purposes Only) , Final Post-Development TN Load Pre-ReDevelopment TN Load(Ib/yr) 5.67 (Post-ReDevelopment&New 7.22 MIIIIIIIIIIII Impervious)(Ib/yr) i 1 1 ) 1 I f 1 J 1 t J Scottsville Elementary School Security Addition ALBEMARLE COUNTY, VIRGINIA MINOR SITE PLAN AMENDMENT DESIGN CALCULATIONS & NARRATIVE FEBRUARY 21, 2017 REVISED APRIL 3, 2017 REVISED JULY 13, 2017 ••s••• • • • �► TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 434.327.1688 AL1T Q CRAIG W I KOT.ARSKT Lic.No. 0402048507 • . 0 7/13 /17 s"ONAL �' Table of Contents Section Title 1 Project Narrative 2 Outlet Protection Sizing 3 Stormwater Quantity Calculations 4 Pre-Developed HydroCAD Calculations 5 Post-Developed HydroCAD Calculations 6 Virginia Runoff Reduction Method ReDevelopment Worksheet Project Narrative: This project includes a building addition to Scottsville Elementary School, an update bus loop, additional parking, sidewalk and associated site work. Limits of disturbance is 0.58 acres. Water Quality: Currently there exists 0.41 acres of managed turf and 0.17 acres of impervious cover within the site limits. In the proposed condition, there will be 0.36 acres of managed turf and 0.22 acres of impervious cover. Per the Virginia Runoff Reduction Redevelopment Spreadsheet, this will require that 0.14 lb/yr to be removed. This required reduction is being met through a surplus removal of 0.41 lb/yr that has been achieved on the Woodbrook Elementary School project. See Plan WPO201600075. This surplus removal will be applied to this project, as ownership for both parcels is the same, the Albemarle County School Board, per 9VAC25-870-69 Section A Part 5. Water Quantity: Water quantity is addressed through modification of the existing stormwater management facility. The facility will be excavated deeper and slightly wider and the outfall structure will be modified. The modified facility will detain and release stormwater at the appropriate rate for channel and flood protection requirements. Channel Protection (Energy Balance): The Energy Balance Equation has been applied to the 1 year storm for the 3.55 acre drainage area to the existing pond. 0.8 * (QPRE-DEVELOPED * "PRE-DEVELOPED)/ I RVPOST-DEVELOPED 3.74 c f s < 0.8 * ((5.03)cfs * (0.381)acft) = 3.83c s I(0.400acft) f Q Developed is 3.74 CFS which is less than the 3.83 CFS satisfying the Energy Balance Equation. Flood Protection (10 year storm): Post-Developed Qio5 Pre-Developed Qio 12.28cfs <_ 13.07cfs Scottsville Elementary School Security Addition ALBEMARLE COUNTY, VIRGINIA MINOR SITE PLAN AMENDMENT DESIGN CALCULATIONS & NARRATIVE FEBRUARY 21, 2017 REVISED APRIL 3, 2017 REVISED JULY 13, 2017 �•••... • 0 TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 434.327.1688 4: ,ALilf op . fAct.4 U CRAIG W.J.KOTARSKI 5 Lic.No. 0402048507 *70 7/13 /17 w . sS74NAL � Table of Contents Section Title 1 Project Narrative 2 Outlet Protection Sizing 3 Stormwater Quantity Calculations 4 Pre-Developed HydroCAD Calculations 5 Post-Developed HydroCAD Calculations 6 Virginia Runoff Reduction Method ReDevelopment Worksheet Project Narrative: This project includes a building addition to Scottsville Elementary School, an update bus loop, additional parking, sidewalk and associated site work. Limits of disturbance is 0.58 acres. Water Quality: Currently there exists 0.41 acres of managed turf and 0.17 acres of impervious cover within the site limits. In the proposed condition, there will be 0.36 acres of managed turf and 0.22 acres of impervious cover. Per the Virginia Runoff Reduction Redevelopment Spreadsheet, this will require that 0.14 lb/yr to be removed. This required reduction is being met through a surplus removal of 0.41 lb/yr that has been achieved on the Woodbrook Elementary School project. See Plan WP0201600075. This surplus removal will be applied to this project, as ownership for both parcels is the same, the Albemarle County School Board, per 9VAC25-870-69 Section A Part 5. Water Quantity: Water quantity is addressed through modification of the existing stormwater management facility. The facility will be excavated deeper and slightly wider and the outfall structure will be modified. The modified facility will detain and release stormwater at the appropriate rate for channel and flood protection requirements. Channel Protection (Energy Balance): The Energy Balance Equation has been applied to the 1 year storm for the 3.55 acre drainage area to the existing pond. 0.8 * (QPRE—DEVELOPED * RVPRE—DEVELOPED) QDeveloped I RVPOST—DEVELOPED 3.74 cfs < 0.8 * ((5.03)cfs * (0.381)acft)/ — 3.83cfs (0.400acft) Q Developed is 3.74 CFS which is less than the 3.83 CFS satisfying the Energy Balance Equation. Flood Protection (10 year storm): Post-Developed QioS Pre-Developed Qio 12.28cfs <_ 13.07cfs