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Beaver Brook As-Built Drainage Cals 07-29-2015HSI No: 3923-121106 July 29, 2015 AS-BUILT STORMWATER MANAGEMENT SYSTEM DRAINAGE CALCULATIONS BEAVER BROOK ESTATES EVERGREEN ROAD NORTHAMPTON, MA Prepared for: Patrick J. Melnik, Trustee The Beaver Brook Nominee Trust 110 King Street Northampton, MA 0 I 060 Prepared by: HER.IT §£. SURVEY] , INC. 241 College High a & Clark Street Post Office B ox 1 South~pton,1 Mh . 01073 (413) 527-~0 July 29, 2015 HSI Job #3923-121106 AS-BUILT STORMWATER SYSTEM VS PROPOSED CONSTRUCTION DRAINAGE SYSTEM SUMMARY BEAVER BROOK ESTATES EVERGREEN ROAD NORTHAMPTON AS-BUILT VS PROPOSED CONSTRUCTION DRAINAGE SUMMARY 2YEARSTORM 10 YEAR STORM 100 YEAR STORM 6PS 0.33 CFS l.41 CFS 3.30 CFS 6PS 0.33 CFS 1.41 CFS 3.30 CFS lP 0.19 CFS 0.95 CFS 3.40 CFS 0.17 CFS 0.43 CFS 0.84 CFS 2P ( COMBINED 0.36 CFS ) ( COMBINED 1.38 ) ( COMBINED 4.24 CFS ) lP-AB 0.21 CFS 0.98 CFS 1.62 CFS SP 0.32 CFS 0.94 CFS 1.94 CFS SP-AB 0.36 CFS 1.01 CFS 2.05 CFS PROPOSED POST SUM= 1.01 CFS SUM= 3.73 CFS SUM = 9.48 CFS CONSTRUCTION AS-BUILT SUM = 0.90 CFS SUM = 3.40 CFS SUM = 6.97 CFS The smaller orange text represents the original Proposed Construction Peaks from the September 4, 2007 drainage calculations. The larger red text is the peak discharges of the As-built stormwater management system. The originally proposed stormwater management system was comprised of six stormwater basins. The As-Built stormwater management system is comprised of five basins (basins 2P & 4P where combined and discharge in to IP). The overall volume provided within the As-built basins is greater than was originally proposed (see enclosed Basin Volume Summary Table). The peak discharges have been decreased from the Proposed stormwater management system to the As-Built stormwater management system along Beaver Brook Loop. July 29, 2015 HSI Job #3923-121106 BASIN lP (MAIN BASIN) 2P&4P (BASIN COMBINED ) (ROTATED BASIN TO THE SOUTH WEST OF MAIN BASIN) 3P (BASIN TO THE SOUTH EAST OF MAIN BASIN) SP (BASIN ON THE SOUTHEASTERLY PORTION OF LOT 15) 6P (BASIN ON THE SOUTHWESTERLY PORTION OF LOT 15) TOTAL VOLUMES BEA VER BROOK ESTATES EVERGREEN ROAD NORTHAMPTON, MA BASIN VOLUME SUMMARY TABLE PROPOSED AS-BUILT BASIN BASIN VOLUME VOLUME CF CF 39,252 46,045 2P-159 1,588 4P-1,026 (l,185 TOTAL) 7,038 7,149 444 301 622 886 48,541 55,969 DIFFERENCE IN VOLUME CF +6,793 +403 +111 -143 +264 +7,428 There is an increase in the overall stormwater management volume provided for the Beaver Brook Estates development. 8 --i>A ~ /\ 8 ~ COMMON DRIVE goMMON DRIVE AS-BUil T-6P fs. DRAINAGE AREA RAINAGE AREA / 7\S-BUILT-SP e e COMMON DRIVE DRAINAGE AREA -TOWN HOUSE& CUL-DE-SAC DRAINAGE AREA COMMOND~ j\ DRAINAGE AREA -t> ~ s -AS-BUILT-2~ COMMON DRIVE -j\ DRAINAGE AREA ~ AS-B~-1 P-ENLARGED tt ~ D /\/ D ~~ COMMON DRIVEWAY- CENTRAL DRAINAGE AREA tt B ~~ AB-GRASS SWALE AS-BUILT-3P ENLARGED Drainage Diagram for 3923 Beaver Brook-Drainage Redesign 07-28-2015 Prepared by Microsoft, Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC AS-BUILT STORMWATER MANAGEMENT SYSTEM AND PROPOSED CONSTRUCTION 2 YEAR STORM EVENT 3.00 INCH RAINFALL AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook-Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 2PS: TOWN HOUSE & CUL-DE-SAC DRAINAGE AREA Runoff = 3.10 cfs @ 12.15 hrs, Volume= 0.258 af, Depth= 1.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr2 YEAR STORM EVENT Rainfall=3.00" Area (sf) CN Description 54, 116 61 >75% Grass cover, Good, HSG B * 10,292 85 Gravel Parking Area * 36,436 98 Paved Roadway, sidewalk and driveway * 12,578 98 BUILDING/WALKS 113,422 79 Weighted Average 64,408 56.79% Pervious Area 49,014 43.21% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.2 43 0.0200 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 2.2 524 0.0050 4.03 4.95 Pipe Channel, 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 2.1 820 0.0100 6.44 11.38 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4. 7' r= 0.38' n= 0.012 0.1 64 0.0130 7.34 12.97 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4. 7' r= 0.38' n= 0.012 9.6 1,451 Total AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 6PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.33 cfs @ 12.14 hrs, Volume= 0.041 af, Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 2 YEAR STORM EVENT Rainfall=3.00" Area (sf) CN Description * 3,011 98 BUILDING 34,884 60 Woods, Fair, HSG B 15,304 61 >75% Grass cover, Good, HSG B 53,199 62 Weighted Average 50,188 94.34% Pervious Area 3,011 5.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.4 50 0.0400 0.19 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.2 15 0.0300 1.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 1.8 126 0.0520 1.14 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 6.4 191 Total AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 7PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.23 cfs @ 12.29 hrs, Volume= 0.029 af, Depth= 0.58" Runoff by SGS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 2 YEAR STORM EVENT Rainfall=3.00" Area (sf) CN Description * 795 98 BUILDING * 893 98 DRIVEWAY * 3,846 85 GRAVEL COMMON DRIVE 9,608 60 Woods, Fair, HSG B 10,448 61 >75% Grass cover Good, HSG B 25,590 67 Weighted Average 23,902 93.40% Pervious Area 1,688 6.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.8 50 0.0100 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 0.2 24 0.0830 2.02 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 17 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 8 0.2000 3.13 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 17.2 99 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment BPS: COMMON DRIVE DRAINAGE AREA Runoff = 0.21 cfs @ 12.14 hrs, Volume= 0.018 af, Depth= 0.81" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 111 24-hr 2 YEAR STORM EVENT Rainfall=3.00" Area (sf) CN Description * 1,029 98 BUILDING * 1,441 98 DRIVEWAY * 1,517 85 GRAVEL COMMON DRIVE 2,054 60 Woods, Fair, HSG B 5,732 61 > 75% Grass cover, Good, HSG B 11,773 72 Weighted Average 9,303 79.02% Pervious Area 2,470 20.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.2 50 0.0600 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 0.2 26 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 15 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 11 0.1820 2.99 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 8.7 102 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 9PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.17 cfs @ 12.17 hrs, Volume= 0.016 af, Depth= 0.76" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 2 YEAR STORM EVENT Rainfall=3.00" Area (sf) CN Description * 1,019 98 BUILDING * 1,374 98 DRIVEWAY * 1,354 85 GRAVEL COMMON DRIVE 3,086 60 Woods, Fair, HSG B 4,411 61 > 75% Grass cover, Good, HSG B 11,244 71 Weighted Average 8,851 78. 72% Pervious Area 2,393 21 .28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 0.7 65 0.1080 1.64 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.1 8 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 11 0.0910 2.11 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 10.6 134 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1 OPS: COMMON DRIVE DRAINAGE AREA Runoff = 0.12 cfs @ 12.21 hrs, Volume= 0.014 af, Depth= 0.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr2 YEAR STORM EVENT Rainfall=3.00" Area (sf) CN Description * 353 98 BUILDING * 467 98 DRIVEWAY * 1,289 85 GRAVEL COMMON DRIVE 5,870 60 Woods, Fair, HSG B 6,214 61 >75% Grass cover, Good, HSG B 14, 193 65 Weighted Average 13,373 94.22% Pervious Area 820 5. 78% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 1.3 113 0.0796 1.41 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.3 19 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 14 0.1430 2.65 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.4 196 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 11 PS: COMMON DRIVEWAY-CENTRAL DRAINAGE AREA Runoff = 1.51 cfs @ 12.21 hrs, Volume= 0.180 af, Depth= 0.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 2 YEAR STORM EVENT Rainfall=3.00" Area (sf) CN Description * 8,927 98 BUILDING * 9,589 98 DRIVEWAY * 7,890 85 GRAVEL COMMON DRIVE 62,424 60 Woods, Fair, HSG B 97,338 61 >75% Grass cover, Good, HSG B 186, 168 65 Weighted Average 167,652 90.05% Pervious Area 18,516 9.95% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 1.8 128 0.0550 1.17 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 16 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 11 0.3640 4.22 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.7 205 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 8 Summary for Reach 3R-AB: AB-GRASS SWALE Inflow Area = 4.274 ac, 9.95% Impervious, Inflow Depth= 0.51" for 2 YEAR STORM EVENT event Inflow = 1.51 cfs@ 12.21 hrs, Volume= 0.180 af Outflow = 1.47 cfs @ 12.27 hrs, Volume= 0.180 af, Atten= 3%, Lag= 3.6 min Routing by Star-Ind+ Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Max. Velocity= 2.03 fps, Min. Travel Time= 1.8 min Avg. Velocity= 0.77 fps, Avg. Travel Time= 4.8 min Peak Storage= 162 cf @ 12.24 hrs Average Depth at Peak Storage= 0.1 O' Bank-Full Depth= 1.00', Capacity at Bank-Full= 59.18 cfs 7.00' x 1.00' deep channel, n= 0.030 Side Slope Z-value= 0.3 '/' Top Width= 7.60' Length= 223.0' Slope= 0.0359 '/' Inlet Invert= 428.00', Outlet Invert= 420.00' AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 9 Summary for Pond 1P-AB: AS-BUILT-1P-ENLARGED Inflow Area= 7.462 ac, 21.77% Impervious, Inflow Depth= 0.50" for 2 YEAR STORM EVENT event Inflow = 3.10 cfs @ 12.15 hrs, Volume= 0.311 af Outflow = 0.21 cfs @ 17.59 hrs, Volume= 0.167 af, Atten= 93%, Lag= 326.9 min Primary = 0.21 cfs @ 17.59 hrs, Volume= 0.167 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 410.97'@ 17.59 hrs Surf.Area= 9,362 sf Storage= 7,290 cf Plug-Flow detention time= 406.9 min calculated for 0.166 af (54% of inflow) Center-of-Mass det. time= 239.6 min ( 1, 150. 7 -911 .1 ) Volume Invert Avail.Storage Storage Description #1 410.00' 46,045 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation {feet} 410.00 411.00 412.00 413.00 414.00 Device #1 #2 Routing Primary Primary Surf.Area Perim. Inc.Store Cum.Store Wet.Area {sg-ft} {feet} {cubic-feet} {cubic-feet} {sg-ft} 5,821 550.0 0 0 5,821 9,488 748.0 7,580 7,580 26,283 11,929 704.0 10,685 18,265 31,419 13,983 640.0 12,942 31,208 38,296 15,708 606.0 14,837 46,045 41,725 Invert Outlet Devices 410.85' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 414.00' 13.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=0.21 cfs@ 17.59 hrs HW=410.97' (Free Discharge) t1 =Orifice/Grate (Weir Controls 0.21 cfs @ 1.13 fps) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfa/1=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 10 Summary for Pond 2-4P-AB: AS-BU IL T-2P & 4P Inflow Area = 0.584 ac, 12.63% Impervious, Inflow Depth = 0.62" for 2 YEAR STORM EVENT event Inflow = 0.28 cfs @ 12.18 hrs, Volume= 0.030 af Outflow = 0.00 cfs@ 0.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 419.73'@24.70 hrs Surf.Area= 1,009 sf Storage= 1,311 cf Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 417.50' 1,588 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area {feet) 417.50 418.00 418.25 418.50 418.75 419.00 419.25 419.50 420.00 Device Routing #1 Primary {sg-ft) {feet) {cubic-feet) {cubic-feet) {sg-ft) 204 67.0 0 0 204 304 82.0 126 126 386 413 97.0 89 215 601 531 112.0 118 333 851 647 123.0 147 480 1,059 749 128.0 174 654 1,164 854 133.0 200 855 1,273 962 139.0 227 1,082 1,407 1,065 144.0 507 1,588 1,540 Invert Outlet Devices 419. 75' 3.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=417.50' (Free Discharge) L1=Broad-Crested Rectangular Weir (Controls 0.00 cfs) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 11 Summary for Pond 3P-AB: AS-BUILT-3P ENLARGED Inflow Area= 4.274 ac, 9.95% Impervious, Inflow Depth= 0.51" for 2 YEAR STORM EVENT event Inflow = 1.47 cfs @ 12.27 hrs, Volume= 0.180 af Outflow = 0.12 cfs@ 16.96 hrs, Volume= 0.053 af, Atten= 92%, Lag= 281.3 min Primary = 0.12 cfs@ 16.96 hrs, Volume= 0.053 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 420.03' @ 16.96 hrs Surf.Area= 3,040 sf Storage= 5,649 cf Plug-Flow detention time= 454.3 min calculated for 0.053 af (29% of inflow) Center-of-Mass det. time= 282.7 min ( 1,195.7-913.0) Volume Invert Avail.Storage Storage Description #1 417.00' 7, 149 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area {feet} 417.00 418.00 419.00 420.00 420.50 Device Routing #1 Primary {sg-ft} {feet} {cubic-feet} {cubic-feet) {sg-ft) 540 120.0 0 0 540 1,582 181.0 1,015 1,015 2,009 2,253 217.0 1,908 2,923 3,166 3,015 248.0 2,625 5,548 4,337 3,394 252.0 1,601 7,149 4,539 Invert Outlet Devices 420.00' 7.5' long x 6.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65 2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83 Primary OutFlow Max=0.11 cfs@ 16.96 hrs HW=420.03' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 0.11 cfs@ 0.43 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook-Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfal/=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 12 Summary for Pond 5P-AB: AS-BUILT-SP Inflow Area = 0.858 ac, 11.13% Impervious, Inflow Depth = 0.65" for 2 YEAR STORM EVENT event Inflow = 0.36 cfs@ 12.28 hrs, Volume= 0.046 af Outflow = 0.36 cfs @ 12.31 hrs, Volume= 0.043 af, Atten= 1 %, Lag= 1.8 min Primary = 0.36 cfs@ 12.31 hrs, Volume= 0.043 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Peak Elev= 421.32' @ 12.31 hrs Surf.Area= 629 sf Storage= 179 cf Plug-Flow detention time= 52.1 min calculated for 0.043 af (93% of inflow) Center-of-Mass det. time= 16. 7 min ( 915.1 -898.4 ) Volume Invert Avail.Storage Storage Description #1 421.00' 301 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area {feet} 421.00 421.25 421.50 Device Routing #1 Primary {sg-ft} {feet} {cubic-feet} {cubic-feet} {sg-ft} 498 135.0 0 0 498 601 140.0 137 137 613 708 145.0 163 301 732 Invert Outlet Devices 421.25' 8.0' long x 2.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=0.35 cfs@ 12.31 hrs HW=421.32' (Free Discharge) t.....1=Broad-Crested Rectangular Weir (Weir Controls 0.35 cfs@ 0.66 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesig Type 11124-hr 2 YEAR STORM EVENT Rainfa/1=3.00" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 13 Summary for Pond 6P-AB: AS-BUil T-6P Inflow Area= 0.587 ac, 6.60% Impervious, Inflow Depth= 0.58" for 2 YEAR STORM EVENT event Inflow = 0.23 cfs @ 12.29 hrs, Volume= 0.029 af Outflow = 0.22 cfs @ 12.33 hrs, Volume= 0.028 af, Atten= 2%, Lag= 2.0 min Primary = 0.22 cfs @ 12.33 hrs, Volume= 0.028 af Routing by Star-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Peak Elev= 422.99' @ 12.33 hrs Surf.Area= 187 sf Storage= 61 cf Plug-Flow detention time= 20.6 min calculated for 0.028 af (98% of inflow) Center-of-Mass det. time= 9. 7 min ( 913.1 -903.4 ) Volume Invert Avail.Storage Storage Description #1 422.25' 886 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation {feet) 422.25 422.50 422.75 423.00 423.25 423.50 423.75 424.00 424.25 424.50 424.75 Device Routing #1 Primary Surf.Area Pe rim. Inc.Store Cum.Store Wet.Area (sg-ft) {feet) {cubic-feet) {cubic-feet) {sg-ft) 0 3.0 0 0 0 40 28.0 3 3 62 129 50.0 20 23 199 190 69.0 40 63 379 276 100.0 58 121 797 372 110.0 81 202 966 440 113.0 101 303 1,026 511 116.0 119 422 1,088 584 120.0 137 559 1, 168 659 123.0 155 714 1,234 722 126.0 173 886 1,301 Invert Outlet Devices 422.76' 12.0" Round Culvert L= 60.0' Ke= 0.500 Inlet I Outlet Invert= 422.76' I 421.19' S= 0.0262 '/' Cc= 0.900 n= 0.010 Primary OutFlow Max=0.22 cfs@ 12.33 hrs HW=422.99' (Free Discharge) t._1=Culvert (Inlet Controls 0.22 cfs@ 1.63 fps) AS-BUILT STORMWATER MANAGEMENT SYSTEM AND PROPOSED· CONSTRUCTION 10 YEAR STORM EVENT 4.50 INCH RAINFALL AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 2PS: TOWN HOUSE & CUL-DE-SAC DRAINAGE AREA Runoff = 6.33 cfs @ 12.14 hrs, Volume= 0.516 af, Depth= 2.38" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 10 YEAR STORM EVENT Rainfall=4.50" Area (sf) CN Description 54, 116 61 >75% Grass cover, Good, HSG B * 10,292 85 Gravel Parking Area * 36,436 98 Paved Roadway, sidewalk and driveway * 12,578 98 BUILDING/WALKS 113,422 79 Weighted Average 64,408 56. 79% Pervious Area 49,014 43.21 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.2 43 0.0200 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 2.2 524 0.0050 4.03 4.95 Pipe Channel, 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 2.1 820 0.0100 6.44 11.38 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.012 0.1 64 0.0130 7.34 12.97 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4. 7' r= 0.38' n= 0.012 9.6 1,451 Total AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 6PS: COMMON DRIVE DRAINAGE AREA Runoff = 1.41 cfs @ 12.11 hrs, Volume= 0.116 af, Depth= 1.14" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 10 YEAR STORM EVENT Rainfall=4.50" Area (sf) CN Description * 3,011 98 BUILDING 34,884 60 Woods, Fair, HSG B 15,304 61 > 75% Grass cover, Good, HSG B 53,199 62 Weighted Average 50,188 94.34% Pervious Area 3,011 5.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.4 50 0.0400 0.19 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.2 15 0.0300 1.21 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 1.8 126 0.0520 1.14 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 6.4 191 Total AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 7PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.68 cfs @ 12.26 hrs, Volume= 0.072 af, Depth= 1.46" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 10 YEAR STORM EVENT Rainfall=4.50" Area (sf) CN Description * 795 98 BUILDING * 893 98 DRIVEWAY * 3,846 85 GRAVEL COMMON DRIVE 9,608 60 Woods, Fair, HSG B 10,448 61 > 75% Grass cover. Good, HSG B 25,590 67 Weighted Average 23,902 93.40% Pervious Area 1,688 6.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.8 50 0.0100 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 0.2 24 0.0830 2.02 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 17 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 8 0.2000 3.13 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 17.2 99 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 8PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.50 cfs @ 12.13 hrs, Volume= 0.041 af, Depth= 1.82" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr10 YEAR STORM EVENT Rainfall=4.50" Area (sf) CN Description * 1,029 98 BUILDING * 1,441 98 DRIVEWAY * 1,517 85 GRAVEL COMMON DRIVE 2,054 60 Woods, Fair, HSG B 5 732 61 > 75% Grass cover, Good HSG B 11,773 72 Weighted Average 9,303 79.02% Pervious Area 2,470 20.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.2 50 0.0600 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 0.2 26 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 15 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 11 0.1820 2.99 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 8.7 102 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7 /30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 9PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.44 cfs @ 12.16 hrs, Volume= 0.038 af, Depth= 1. 75" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr 10 YEAR STORM EVENT Rainfall=4.50" Area (sf) CN Description * 1,019 98 BUILDING * 1,374 98 DRIVEWAY * 1,354 85 GRAVEL COMMON DRIVE 3,086 60 Woods, Fair, HSG B 4,411 61 >75% Grass cover, Good, HSG B 11,244 71 Weighted Average 8,851 78. 72% Pervious Area 2,393 21 .28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 0.7 65 0.1080 1.64 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.1 8 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 11 0.0910 2.11 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 10.6 134 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1 OPS: COMMON DRIVE DRAINAGE AREA Runoff = 0.39 cfs @ 12.17 hrs, Volume= 0.036 af, Depth= 1.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 10 YEAR STORM EVENT Rainfall=4.50" Area (sf) CN Description * 353 98 BUILDING * 467 98 DRIVEWAY * 1,289 85 GRAVEL COMMON DRIVE 5,870 60 Woods, Fair, HSG B 6,214 61 >75% Grass cover, Good, HSG B 14, 193 65 Weighted Average 13,373 94.22% Pervious Area 820 5. 78% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 1.3 113 0.0796 1.41 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.3 19 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 14 0.1430 2.65 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.4 196 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 11 PS: COMMON DRIVEWAY-CENTRAL DRAINAGE AREA Runoff = 5.02 cfs@ 12.18 hrs, Volume= 0.474 af, Depth= 1.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 111 24-hr 10 YEAR STORM EVENT Rainfall=4.50" Area (sf) CN Description * 8,927 98 BUILDING * 9,589 98 DRIVEWAY * 7,890 85 GRAVEL COMMON DRIVE 62,424 60 Woods, Fair, HSG B 97,338 61 > 75% Grass cover, Good, HSG B 186,168 65 Weighted Average 167,652 90.05% Pervious Area 18,516 9.95% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 1.8 128 0.0550 1.17 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 16 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 11 0.3640 4.22 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.7 205 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook-Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.1 O s/n 00860 © 201 O HydroCAD Software Solutions LLC Page 8 Summary for Reach 3R-AB: AB-GRASS SWALE Inflow Area = 4.274 ac, 9.95% Impervious, Inflow Depth= 1.33" for 10 YEAR STORM EVENT event Inflow = 5.02cfs@ 12.18hrs, Volume= 0.474af Outflow = 4.89 cfs@ 12.22 hrs, Volume= 0.474 af, Atten= 2%, Lag= 2.2 min Routing by Stor-lnd+ Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Max. Velocity= 3.26 fps, Min. Travel Time= 1.1 min Avg. Velocity = 1.03 fps, Avg. Travel Time= 3.6 min Peak Storage= 340 cf @ 12.20 hrs Average Depth at Peak Storage= 0.22' Bank-Full Depth= 1.00', Capacity at Bank-Full= 59.18 cfs 7.00' x 1.00' deep channel, n= 0.030 Side Slope Z-value= 0.3 '/' Top Width= 7.60' Length= 223.0' Slope= 0.0359 '/' Inlet Invert= 428.00', Outlet Invert= 420.00' AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfa/1=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 9 Summary for Pond 1 P-AB: AS-BUil T-1 P-ENLARGED Inflow Area= 7.462 ac, 21.77% Impervious, Inflow Depth= 1.46" for 10 YEAR STORM EVENT event Inflow = 6.33 cfs@ 12.14 hrs, Volume= 0.905 af Outflow = 0.98 cfs@ 14.56 hrs, Volume= 0.760 af, Atten= 84%, Lag= 144.9 min Primary = 0.98 cfs@ 14.56 hrs, Volume= 0.760 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 411.93'@ 14.56 hrs Surf.Area= 11,750 sf Storage= 17,441 cf Plug-Flow detention time= 250.8 min calculated for 0.759 af (84% of inflow) Center-of-Mass det. time= 179.8 min ( 1,060.5 -880. 7 ) Volume Invert Avail.Storage Storage Description #1 410.00' 46,045 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation {feet} 410.00 411.00 412.00 413.00 414.00 Device #1 #2 Routing Primary Primary Surf.Area Perim. Inc.Store Cum.Store Wet.Area {sg-ft} {feet} {cubic-feet} {cubic-feet} {sg-ft} 5,821 550.0 0 0 5,821 9,488 748.0 7,580 7,580 26,283 11,929 704.0 10,685 18,265 31,419 13,983 640.0 12,942 31,208 38,296 15,708 606.0 14,837 46,045 41,725 Invert Outlet Devices 410.85' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 414.00' 13.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=0.98 cfs @ 14.56 hrs HW=411 .93' (Free Discharge) t1=0rifice/Grate (Orifice Controls 0.98 cfs@ 5.00 fps) 2=Broad-Crested Rectangular Weir (Controls 0.00 cfs) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook-Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 10 Summary for Pond 2-4P-AB: AS-BUil T-2P & 4P Inflow Area= 0.584 ac, 12.63% Impervious, Inflow Depth = 1.51" for 10 YEAR STORM EVENT event Inflow = 0.82 cfs @ 12.17 hrs, Volume= 0.07 4 af Outflow = 0.18 cfs@ 12.72 hrs, Volume= 0.043 af, Atten= 78%, Lag= 33.1 min Primary = 0.18 cfs @ 12. 72 hrs, Volume= 0.043 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 419.84' @ 12. 72 hrs Surf.Area= 1,031 sf Storage= 1,418 cf Plug-Flow detention time= 228.0 min calculated for 0.043 af (59% of inflow) Center-of-Mass det. time= 107 .5 min ( 971.2 -863. 7 ) Volume Invert Avail.Storage Storage Description #1 417.50' 1,588 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation (feet) 417.50 418.00 418.25 418.50 418.75 419.00 419.25 419.50 420.00 Device Routing #1 Primary Surf.Area Perim. Inc.Store Cum.Store Wet.Area (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 204 67.0 0 0 204 304 82.0 126 126 386 413 97.0 89 215 601 531 112.0 118 333 851 647 123.0 147 480 1,059 749 128.0 174 654 1,164 854 133.0 200 855 1,273 962 139.0 227 1,082 1,407 1,065 144.0 507 1,588 1,540 Invert Outlet Devices 419. 75' 3.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2. 70 2. 7 4 2. 79 2.88 Primary OutFlow Max=0.18 cfs@ 12.72 hrs HW=419.84' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 0.18 cfs@ 0.69 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 11 Summary for Pond 3P-AB: AS-BUil T-3P ENLARGED Inflow Area= 4.27 4 ac, 9.95% Impervious, Inflow Depth = 1.33" for 10 YEAR STORM EVENT event Inflow = 4.89 cfs@ 12.22 hrs, Volume= 0.474 af Outflow = 2.63 cfs@ 12.52 hrs, Volume= 0.346 af, Atten= 46%, Lag= 18.0 min Primary = 2.63 cfs @ 12.52 hrs, Volume= 0.346 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 420.28' @ 12.52 hrs Surf.Area= 3,221 sf Storage= 6,407 cf Plug-Flow detention time= 163.4 min calculated for 0.346 af (73% of inflow) Center-of-Mass det. time= 64.4 min ( 941.0 -876.7) Volume Invert Avail.Storage Storage Description #1 417.00' 7, 149 cf Custom Stage Data (Irregular) Listed below (Recatc) Elevation Surf.Area Pe rim. Inc.Store Cum.Store Wet.Area (feet} 417.00 418.00 419.00 420.00 420.50 Device Routing #1 Primary (sg-ft} (feet} (cubic-feet} (cubic-feet} (sg-ft} 540 120.0 0 0 540 1,582 181.0 1,015 1,015 2,009 2,253 217.0 1,908 2,923 3,166 3,015 248.0 2,625 5,548 4,337 3,394 252.0 1,601 7,149 4,539 Invert Outlet Devices 420.00' 7.5' long x 6.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65 2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83 Primary OutFlow Max=2.59 cfs@ 12.52 hrs HW=420.27' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 2.59 cfs@ 1.26 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfaf/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 12 Summary for Pond SP-AB: AS-BUILT-SP Inflow Area= 0.858 ac, 11.13% Impervious, Inflow Depth = 1.57" for 1 O YEAR STORM EVENT event Inflow = 1.01 cfs @ 12.22 hrs, Volume= 0.112 af Outflow = 1.01 cfs @ 12.24 hrs, Volume= 0.109 af, Atten= 1 %, Lag= 1.2 min Primary = 1.01 cfs @ 12.24 hrs, Volume= 0.109 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Peak Elev= 421.38' @ 12.24 hrs Surf.Area= 658 sf Storage= 222 cf Plug-Flow detention time= 23.3 min calculated for 0.109 af (97% of inflow) Center-of-Mass det. time= 7.8 min ( 875.6 -867.8) Volume Invert Avail.Storage Storage Description #1 421.00' 301 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area {feet} 421.00 421.25 421.50 Device Routing #1 Primary {sg-ft} {feet} {cubic-feet} {cubic-feet} {sg-ft} 498 135.0 0 0 498 601 140.0 137 137 613 708 145.0 163 301 732 Invert Outlet Devices 421.25' 8.0' long x 2.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=1.00 cfs@ 12.24 hrs HW=421.38' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 1.00 cfs@ 0.93 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redesi Type 11124-hr 10 YEAR STORM EVENT Rainfal/=4.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 13 Summary for Pond 6P-AB: AS-BUILT-6P Inflow Area = 0.587 ac, 6.60% Impervious, Inflow Depth = 1.46" for 10 YEAR STORM EVENT event Inflow = 0.68 cfs @ 12.26 hrs, Volume= 0.072 af Outflow = 0.67 cfs @ 12.29 hrs, Volume= 0.071 af, Atten= 2%, Lag= 1.6 min Primary = 0.67 cfs @ 12.29 hrs, Volume= 0.071 af Routing by Star-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Peak Elev= 423.17' @ 12.29 hrs Surf.Area= 247 sf Storage= 100 cf Plug-Flow detention time= 10.3 min calculated for 0.071 af (99% of inflow) Center-of-Mass det. time= 5.5 min ( 877.8 -872.3 ) Volume Invert Avail.Storage Storage Description #1 422.25' 886 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area {feet} {sg-ft} {feet} {cubic-feet} {cubic-feet} {sg-ft} 422.25 0 3.0 0 0 0 422.50 40 28.0 3 3 62 422.75 129 50.0 20 23 199 423.00 190 69.0 40 63 379 423.25 276 100.0 58 121 797 423.50 372 110.0 81 202 966 423.75 440 113.0 101 303 1,026 424.00 511 116.0 119 422 1,088 424.25 584 120.0 137 559 1, 168 424.50 659 123.0 155 714 1,234 424.75 722 126.0 173 886 1,301 Device Routing Invert Outlet Devices #1 Primary 422.76' 12.0" Round Culvert L= 60.0' Ke= 0.500 Inlet/ Outlet Invert= 422.76' I 421.19' S= 0.0262 '/' Cc= 0.900 n= 0.010 Primary OutFlow Max=0.66 cfs @ 12.29 hrs HW=423.17' (Free Discharge) L1=Culvert (Inlet Controls 0.66 cfs@ 2.18 fps) AS-BUILT STORMWATER MANAGEMENT SYSTEM AND PROPOSED CONSTRUCTION 100 YEAR STORM EVENT 6.50 INCH RAINFALL AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type Ill 24-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 2PS: TOWN HOUSE & CUL-DE-SAC DRAINAGE AREA Runoff = 10.95 cfs @ 12.14 hrs, Volume= 0.896 af, Depth= 4.13" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type I 11 24-hr 100 YEAR STORM EVENT Rainfall=6.50" Area (sf) CN Description 54,116 61 >75% Grass cover, Good, HSG B * 10,292 85 Gravel Parking Area * 36,436 98 Paved Roadway, sidewalk and driveway * 12,578 98 BUILDING/WALKS 113,422 79 Weighted Average 64,408 56. 79% Pervious Area 49,014 43.21 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.2 43 0.0200 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 2.2 524 0.0050 4.03 4.95 Pipe Channel, 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 2.1 820 0.0100 6.44 11.38 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4. 7' r= 0.38' n= 0.012 0.1 64 0.0130 7.34 12.97 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4. 7' r= 0.38' n= 0.012 9.6 1,451 Total AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type 11124-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7 /30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 6PS: COMMON DRIVE DRAINAGE AREA Runoff = 3.30 cfs @ 12.10 hrs, Volume= 0.248 af, Depth= 2.44" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr 100 YEAR STORM EVENT Rainfall=6.50" * Area (sf) CN Description 98 BUILDING 60 Woods, Fair, HSG B 3,011 34,884 15,304 61 >75% Grass cover, Good HSG B 53,199 50,188 3,011 62 Weighted Average 94.34% Pervious Area 5.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.4 50 0.0400 0.19 0.2 15 0.0300 1.21 1.8 126 0.0520 1.14 6.4 191 Total Sheet Flow, Grass: Short n= 0.150 P2= 3.00" Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Woodland Kv= 5.0 fps AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type Ill 24-hr 100 YEAR STORM EVENT Rainfal/=6. 50" Prepared by Microsoft Printed 7 /30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 7PS: COMMON DRIVE DRAINAGE AREA Runoff = 1.41 cfs @ 12.25 hrs, Volume= 0.143 af, Depth= 2.91" Runoff by SGS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr 100 YEAR STORM EVENT Rainfall=6.50" Area (sf) CN Description * 795 98 BUILDING * 893 98 DRIVEWAY * 3,846 85 GRAVEL COMMON DRIVE 9,608 60 Woods, Fair, HSG B 10,448 61 >75% Grass cover, Good, HSG B 25,590 67 Weighted Average 23,902 93.40% Pervious Area 1,688 6.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.8 50 0.0100 0.05 Sheet Flow, Woods: Light underbrush n= 0.400 0.2 24 0.0830 2.02 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 17 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 8 0.2000 3.13 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 17.2 99 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type Ill 24-hr 100 YEAR STORM EVENT Rainfal/=6. 50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment BPS: COMMON DRIVE DRAINAGE AREA Runoff = 0.96 cfs @ 12.13 hrs, Volume= 0.077 af, Depth= 3.41" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr100 YEAR STORM EVENT Rainfall=6.50" Area (sf) CN Description * 1,029 98 BUILDING * 1,441 98 DRIVEWAY * 1,517 85 GRAVEL COMMON DRIVE 2,054 60 Woods, Fair, HSG B 5,732 61 >75% Grass cover, Good, HSG B 11,773 72 Weighted Average 9,303 79.02% Pervious Area 2,470 20.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.2 50 0.0600 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 0.2 26 0.1700 2.89 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.2 15 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 11 0.1820 2.99 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 8.7 102 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type Ill 24-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 9PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.85 cfs @ 12.15 hrs, Volume= 0.071 af, Depth= 3.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr100 YEAR STORM EVENT Rainfall=6.50" * * * Area (sf) Tc (min) 9.7 0.7 0.1 0.1 10.6 1,019 1,374 1,354 3,086 4,411 11,244 8,851 2,393 Length (feet) 50 65 8 11 134 CN Description 98 BUILDING 98 DRIVEWAY 85 GRAVEL COMMON DRIVE 60 Woods, Fair, HSG B 61 >75% Grass cover, Good, HSG B 71 Weighted Average 78.72% Pervious Area 21.28% Impervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 0.1080 1.64 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0910 2.11 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type 11124-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 10PS: COMMON DRIVE DRAINAGE AREA Runoff = 0.85 cfs @ 12.17 hrs, Volume= 0.074 af, Depth= 2.72" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type 11124-hr 100 YEAR STORM EVENT Rainfall=6.50" Area (sf) CN Description * 353 98 BUILDING * 467 98 DRIVEWAY * 1,289 85 GRAVEL COMMON DRIVE 5,870 60 Woods, Fair, HSG B 6,214 61 > 75% Grass cover, Good, HSG B 14, 193 65 Weighted Average 13,373 94.22% Pervious Area 820 5.78% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 1.3 113 0.0796 1.41 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.3 19 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 14 0.1430 2.65 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.4 196 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook-Drainage Redes Type Ill 24-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 11PS: COMMON DRIVEWAY-CENTRAL DRAINAGE AREA Runoff = 11.03 cfs@ 12.17 hrs, Volume= 0.969 af, Depth= 2.72" Runoff by SGS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type Ill 24-hr 100 YEAR STORM EVENT Rainfall=6.50" Area (sf) CN Description * 8,927 98 BUILDING * 9,589 98 DRIVEWAY * 7,890 85 GRAVEL COMMON DRIVE 62,424 60 Woods, Fair, HSG B 97,338 61 > 75% Grass cover, Good, HSG B 186,168 65 Weighted Average 167,652 90.05% Pervious Area 18,516 9.95% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 1.8 128 0.0550 1.17 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 16 0.0050 1.14 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.0 11 0.3640 4.22 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 11.7 205 Total P2= 3.00" AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type Ill 24-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 8 Summary for Reach 3R-AB: AB-GRASS SWALE Inflow Area= 4.274 ac, 9.95% Impervious, Inflow Depth= 2.72" for 100 YEAR STORM EVENT event Inflow = 11.03 cfs @ 12.17 hrs, Volume= 0.969 af Outflow = 10.66 cfs@ 12.20 hrs, Volume= 0.969 af, Atten= 3%, Lag= 1.7 min Routing by Stor-lnd+ Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Max. Velocity= 4.37 fps, Min. Travel Time= 0.9 min Avg. Velocity= 1.28 fps, Avg. Travel Time= 2.9 min Peak Storage= 550 cf @ 12.18 hrs Average Depth at Peak Storage= 0.35' Bank-Full Depth= 1.00', Capacity at Bank-Full= 59.18 cfs 7.00' x 1.00' deep channel, n= 0.030 Side Slope Z-value= 0.3 '/' Top Width= 7.60' Length= 223.0' Slope= 0.0359 '/' Inlet Invert= 428.00', Outlet Invert= 420.00' AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type 11124-hr 100 YEAR STORM EVENT Rainfaf/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 9 Summary for Pond 1 P-AB: AS-BUil T-1 P-ENLARGED Inflow Area = 7.462 ac, 21.77% Impervious, Inflow Depth= 2.98" for 100 YEAR STORM EVENT event Inflow = 22. 79 cfs @ 12.20 hrs, Volume= 1.850 af Outflow = 1.62 cfs@ 14.71 hrs, Volume= 1.695 af, Atten= 93%, Lag= 150.5 min Primary = 1.62 cfs@ 14.71 hrs, Volume= 1.695 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 413. 79' @ 14. 71 hrs Surf.Area= 15,333 sf Storage= 42, 7 49 cf Plug-Flow detention time= 340.1 min calculated for 1.692 af (91 % of inflow) Center-of-Mass det. time= 297 .8 min ( 1, 149.6 -851. 7 ) Volume Invert Avail.Storage Storage Description #1 410.00' 46,045 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation {feet} 410.00 411.00 412.00 413.00 414.00 Device #1 #2 Routing Primary Primary Surf.Area Perim. Inc.Store Cum.Store Wet.Area {sg-ft} {feet} {cubic-feet} {cubic-feet} {sg-ft} 5,821 550.0 0 0 5,821 9,488 748.0 7,580 7,580 26,283 11,929 704.0 10,685 18,265 31,419 13,983 640.0 12,942 31,208 38,296 15,708 606.0 14,837 46,045 41,725 Invert Outlet Devices 410.85' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 414.00' 13.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=1.62 cfs @ 14. 71 hrs HW=413. 79' (Free Discharge) t1=0rifice/Grate (Orifice Controls 1.62 cfs@ 8.25 fps) 2=Broad-Crested Rectangular Weir (Controls 0.00 cfs) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type 11124-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 10 Summary for Pond 2-4P-AB: AS-BUil T-2P & 4P Inflow Area = 0.584 ac, 12.63% Impervious, Inflow Depth= 2.98" for 100 YEAR STORM EVENT event Inflow = 1.69 cfs @ 12.16 hrs, Volume= 0.145 af Outflow = 1.64 cfs @ 12.22 hrs, Volume= 0.114 af, Atten= 3%, Lag= 3.6 min Primary = 1.64 cfs @ 12.22 hrs, Volume= 0.114 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 420.12'@ 12.22 hrs Surf.Area= 1,065 sf Storage= 1,588 cf Plug-Flow detention time= 128.1 min calculated for 0.114 af (79% of inflow) Center-of-Mass det. time= 46.1 min ( 889.8 -843.7) Volume Invert Avail.Storage Storage Description #1 417.50' 1,588 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation (feet) 417.50 418.00 418.25 418.50 418.75 419.00 419.25 419.50 420.00 Device Routing #1 Primary Surf.Area Perim. Inc.Store Cum.Store Wet.Area (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 204 67.0 0 0 204 304 82.0 126 126 386 413 97.0 89 215 601 531 112.0 118 333 851 647 123.0 147 480 1,059 749 128.0 174 654 1, 164 854 133.0 200 855 1,273 962 139.0 227 1,082 1,407 1,065 144.0 507 1,588 1,540 Invert Outlet Devices 419. 75' 3.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2. 70 2. 7 4 2. 79 2.88 Primary OutFlow Max=1.49 cfs @ 12.22 hrs HW=420.09' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 1.49 cfs@ 1.44 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook-Drainage Redes Type Ill 24-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 11 Summary for Pond 3P-AB: AS-BUil T-3P ENLARGED Inflow Area = 4.274 ac, 9.95% Impervious, Inflow Depth= 2.72" for 100 YEAR STORM EVENT event Inflow = 10.66 cfs @ 12.20 hrs, Volume= 0.969 af Outflow = 11.95 cfs@ 12.21 hrs, Volume= 0.840 af, Atten= 0%, Lag= 0.5 min Primary ·= 11 .95 cfs @ 12.21 hrs, Volume= 0.840 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 3 Peak Elev= 420.71'@ 12.21 hrs Surf.Area= 3,394 sf Storage= 7,149 cf Plug-Flow detention time= 90.4 min calculated for 0.838 af (87% of inflow) Center-of-Mass det. time= 30.0 min ( 883.9 -853.9 ) Volume Invert Avail.Storage Storage Description #1 417.00' 7,149 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area {feet) 417.00 418.00 419.00 420.00 420.50 Device Routing #1 Primary {sg-ft} {feet} {cubic-feet) {cubic-feet) {sg-ft} 540 120.0 0 0 540 1,582 181.0 1,015 1,015 2,009 2,253 217.0 1,908 2,923 3,166 3,015 248.0 2,625 5,548 4,337 3,394 252.0 1,601 7,149 4,539 Invert Outlet Devices 420.00' 7.5' long x 6.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65 2.65 2.66 2.66 2.67 2.69 2. 72 2. 76 2.83 Primary OutFlow Max=11.46 cfs@ 12.21 hrs HW=420.69' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 11.46 cfs@ 2.23 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type 11124-hr 100 YEAR STORM EVENT Rainfal/=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 12 Summary for Pond SP-AB: AS-BUil T-5P Inflow Area = 0.858 ac, 11.13% Impervious, Inflow Depth = 3.06" for 100 YEAR STORM EVENT event Inflow = 2.05 cfs @ 12.21 hrs, Volume= 0.219 af Outflow = 2.05 cfs@ 12.22 hrs, Volume= 0.216 af, Atten= 0%, Lag= 0.8 min Primary = 2.05 cfs@ 12.22 hrs, Volume= 0.216 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Peak Elev= 421.47'@ 12.22 hrs Surf.Area= 693 sf Storage= 277 cf Plug-Flow detention time= 14.1 min calculated for 0.216 af (99% of inflow) Center-of-Mass det. time= 5.5 min ( 852.9 -847.5 ) Volume Invert Avail.Storage Storage Description #1 421.00' 301 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Perim. (feet) Inc.Store (cubic-feet) Cum.Store (cubic-feet) Wet.Area (sg-ft) 421.00 421.25 421.50 Device Routing #1 Primary 498 601 708 135.0 140.0 145.0 0 137 163 0 137 301 498 613 732 Invert Outlet Devices 421.25' 8.0' long x 2.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2. 70 2. 77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=2.03 cfs@ 12.22 hrs HW=421.47' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 2.03 cfs@ 1.18 fps) AS-BUILT STORMWATER SYSTEM 3923 Beaver Brook -Drainage Redes Type 11124-hr 100 YEAR STORM EVENT Rainfa/1=6.50" Prepared by Microsoft Printed 7/30/2015 HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 13 Summary for Pond 6P-AB: AS-BUILT-SP Inflow Area = 0.587 ac, 6.60% Impervious, Inflow Depth = 2.91" for 100 YEAR STORM EVENT event Inflow = 1.41 cfs @ 12.25 hrs, Volume= 0.143 af Outflow = 1.39 cfs @ 12.27 hrs, Volume= 0.142 af, Atten= 1 %, Lag= 1.5 min Primary = 1.39 cfs @ 12.27 hrs, Volume= 0.142 af Routing by Stor-lnd method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs I 2 Peak Elev= 423.39'@ 12.27 hrs Surf.Area= 326 sf Storage= 162 cf Plug-Flow detention time= 6. 7 min calculated for 0.142 af (100% of inflow) Center-of-Mass det. time= 4.1 min ( 855.7 -851.6) Volume Invert Avail.Storage Storage Description #1 422.25' 886 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet} {sg-ft} (feet} {cubic-feet} {cubic-feet} (sg-ft} 422.25 0 3.0 0 0 0 422.50 40 28.0 3 3 62 422.75 129 50.0 20 23 199 423.00 190 69.0 40 63 379 423.25 276 100.0 58 121 797 423.50 372 110.0 81 202 966 423.75 440 113.0 101 303 1,026 424.00 511 116.0 119 422 1,088 424.25 584 120.0 137 559 1, 168 424.50 659 123.0 155 714 1,234 424.75 722 126.0 173 886 1,301 Device Routing Invert Outlet Devices #1 Primary 422.76' 12.0" Round Culvert L= 60.0' Ke= 0.500 Inlet I Outlet Invert= 422. 76' I 421.19' S= 0.0262 '/' Cc= 0.900 n= 0.010 Primary OutFlow Max=1.38 cfs@ 12.27 hrs HW=423.38' (Free Discharge) L1=Culvert (Inlet Controls 1.38 cfs@ 2.69 fps)