stormwater management report - haverhill€¦ · 01/02/2018 · qu = the unit peak discharge in...
TRANSCRIPT
Stormwater Management Permit
Proposed Trade School Facility Hilldale Avenue
Wilmington, Massachusetts
Stormwater Management Calculations
Prepared for:
New England Tractor Trailer Training School
1600 Osgood Street, Unit 1570 North Andover, MA 01845
Prepared by:
Dana F. Perkins, Inc.
1057 East Street Tewksbury, MA 01876
Submitted To: City of Haverhill ~ Planning Board
STORMWATER CALCULATIONS
Proposed Trade School Facility Hilldale Avenue
Haverhill, Massachusetts
Required Recharge Volume
Total Proposed Impervious Area = 296,126 SF ± (“C” Soils)
Infiltration Standard for “C” Soils = 0.27 inches of runoff
Required Recharge Volume = Impervious Area x Infiltration Standard
Required Volume to Recharge = 296,126 SF x (0.27 IN x 1 FT/12 IN) »» 6,663 CF
Volume Provided in Infiltration Chambers
Storage volume provided per Infiltration System #1 = 9,113 CF ±
Storage volume provided per Infiltration System #2 = 207 CF ±
Total storage volume provided = 9,113 + 207 »» 9,320 CF
9,320 CF > 6,663 CF
Water Quality Treatment Volume
The hydrodynamic separator units are sized based on flow capacity of a 1.0" Equivalent
Water Quality Flow rate.
WQF = (Qu) x (A) x (WQV)
WQF = Water Quality Flow
Qu = the unit peak discharge in CSM/IN = 795 CSM/IN
A = impervious surface drainage area in square miles
WQV = water quality volume in watershed inches = 1 IN
CDS Unit 1
A = 216,107 SF = 0.00775 MILES²
WQF = 795 CSM/IN x 0.00775 MILES² x 1 IN »» 6.16 CFS
CDS4045 Treatment Capacity = 7.5 CFS > 6.16 CFS
CDS Unit 2
A = 61,973 SF = 0.00222 MILES²
WQF = 795 CSM/IN x 0.00222 MILES² x 1 IN »» 1.76 CFS
CDS3020 Treatment Capacity = 2.0 CFS > 1.76 CFS
CDS Unit 3
A = 18,046 SF = 0.00065 MILES²
WQF = 795 CSM/IN x 0.00065 MILES² x 1 IN »» 0.52 CFS
CDS2015 Treatment Capacity = 0.7 CFS > 0.52 CFS
Infiltration BMPs ~ Draw Down Time
Infiltration Rate (“C” Soils) = 0.27 IN/HR = 0.0225 FT/HR
Total storage volume provided within Infiltration System #1 = 9,113 CF
Surface Area for Infiltration System #1 = 18,225 SF
Draw Down Rate (CF/HR) = 18,225 SF x 0.0225 FT/HR »» 410 CF/HR
Draw Down Time = 9,113 CF / (410 CF/HR) »» 22.2 hours
72 hours > 22.2 hours
Total storage volume provided within Infiltration System #2 = 207 CF
Surface Area for Infiltration System #2 = 414 SF
Draw Down Rate (CF/HR) = 414 SF x 0.0225 FT/HR »» 9 CF/HR
Draw Down Time = 207 CF / (9 CF/HR) »» 23 hours
72 hours > 23 hours
Location: Proposed Trade School Facility ~ TSS Treatment Removal Hilldale Avenue, Haverhill, MA A B C D E
TSS
Rem
oval
C
alcu
latio
n W
orks
heet
BMP
TSS Removal Rate Starting TSS
Load* Amount Removed (BxC)
Remaining Load (C-D)
Deep-Sump Catch Basin
0.25
1.00*
0.25
0.75
CDS Unit
0.65
0.75
0.49
0.26
Subsurface Structures (Infiltration Chambers)
0.80
0.26
0.21
0.05
.
TOTAL TSS REMOVAL =
95%
*Equals remaining load from previous BMP (E) which enters the BMP
Project: Proposed Trade School Facility ~ Hilldale Avenue, Haverhill, Massachusetts Prepared By: Dana F. Perkins, Inc. Date: December 12, 2017
Stormwater Management Permit
Proposed Trade School Facility Hilldale Avenue
Haverhill, Massachusetts
Hydrological Analysis
Prepared for:
New England Tractor Trailer Training School 1600 Osgood Street, Unit 1570
North Andover, MA 01845
Prepared by:
Dana F. Perkins, Inc. 1057 East Street
Tewksbury, MA 01876
Submitted To: City of Haverhill ~ Planning Board
Stormwater Summary
Pre‐development Conditions
The existing conditions stormwater runoff consists of two separate subcatchments. A portion of the existing site is directed towards the existing bordering vegetated wetlands to the north of the property and a portion of the existing site is directed towards the existing bordering vegetated wetlands to the south of the property. Portions of the site run along existing swales located partially on our property and partially within the Hilldale Avenue right of way prior to entering the wetlands to the north. These portions of land have been included in the subcatchment for the existing bordering vegetated wetlands to the north.
Post‐development Conditions
The project has been designed to capture and recharge the required recharge volume for post‐development stormwater runoff on‐site, with overflows directed towards the existing bordering vegetated wetlands located on site. A HydroCAD report has been included demonstrating that the proposed stormwater system reduces peak rates of runoff below pre‐development rates.
Subcatchment #1 ‐ Northern existing bordering vegetated wetlands
Storm Existing Proposed Difference 2‐Year (3.2") 3.62 cfs 3.55 cfs ‐0.07 cfs 10‐Year (5.07") 11.28 cfs 10.89 cfs ‐0.39 cfs 25‐Year (6.24") 16.87 cfs 16.85 cfs ‐0.02 cfs 100‐Year (8.05") 26.14 cfs 25.96 cfs ‐0.18 cfs
Subcatchment #2‐ Southern existing bordering vegetated wetlands
Storm Existing Proposed Difference 2‐Year (3.2") 2.27 cfs 2.21 cfs ‐0.06 cfs 10‐Year (5.07") 7.49 cfs 5.82 cfs ‐1.67 cfs 25‐Year (6.24") 11.37 cfs 8.00 cfs ‐3.37 cfs 100‐Year (8.05") 17.84 cfs 11.39 cfs ‐6.45 cfs
Drainage Diagram for HydrologyPrepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcat Reach Pond Link
EX-1A
Subcatchment 1A
EX-1B
Subcatchment 1B
EX-2A
Subcatchment 2A
EX-NORTH
Existing BVW - North
EX-SOUTH
Existing BVW - South
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 2Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7,657 sf Runoff Depth=0.78"Subcatchment EX-1A: Subcatchment 1A Flow Length=94' Tc=5.1 min CN=69 Runoff=0.15 cfs 0.011 af
Runoff Area=222,696 sf Runoff Depth=0.69"Subcatchment EX-1B: Subcatchment 1B Flow Length=349' Tc=5.7 min CN=67 Runoff=3.48 cfs 0.292 af
Runoff Area=206,683 sf Runoff Depth=0.64"Subcatchment EX-2A: Subcatchment 2A Flow Length=413' Tc=13.2 min CN=66 Runoff=2.27 cfs 0.253 af
Inflow=3.62 cfs 0.304 afLink EX-NORTH: Existing BVW - North Primary=3.62 cfs 0.304 af
Inflow=2.27 cfs 0.253 afLink EX-SOUTH: Existing BVW - South Primary=2.27 cfs 0.253 af
Total Runoff Area = 10.033 ac Runoff Volume = 0.557 af Average Runoff Depth = 0.67"
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 3Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-1A: Subcatchment 1A
Runoff = 0.15 cfs @ 12.09 hrs, Volume= 0.011 af, Depth= 0.78"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description6,659 70 Woods, Good, HSG C
998 65 Brush, Good, HSG C7,657 69 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.7 25 0.1000 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.3 61 0.0246 0.8 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
0.1 8 0.2410 2.5 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
5.1 94 Total
Subcatchment EX-1B: Subcatchment 1B
Runoff = 3.48 cfs @ 12.10 hrs, Volume= 0.292 af, Depth= 0.69"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description114,305 65 Brush, Good, HSG C108,391 70 Woods, Good, HSG C222,696 67 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.1 50 0.0100 0.3 Sheet Flow, Fallow n= 0.050 P2= 3.20"
0.9 133 0.1243 2.5 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.4 38 0.0526 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
1.0 99 0.0606 1.7 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.3 29 0.0517 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
5.7 349 Total
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 4Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-2A: Subcatchment 2A
Runoff = 2.27 cfs @ 12.22 hrs, Volume= 0.253 af, Depth= 0.64"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description35,995 70 Woods, Good, HSG C
170,688 65 Brush, Good, HSG C206,683 66 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
6.2 50 0.1100 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.1 83 0.0602 1.2 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.6 67 0.0075 0.4 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
1.0 75 0.0670 1.3 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.3 138 0.0399 1.0 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
13.2 413 Total
Link EX-NORTH: Existing BVW - North
Inflow Area = 5.288 ac, Inflow Depth = 0.69" for 2-year event eventInflow = 3.62 cfs @ 12.10 hrs, Volume= 0.304 afPrimary = 3.62 cfs @ 12.10 hrs, Volume= 0.304 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link EX-SOUTH: Existing BVW - South
Inflow Area = 4.745 ac, Inflow Depth = 0.64" for 2-year event eventInflow = 2.27 cfs @ 12.22 hrs, Volume= 0.253 afPrimary = 2.27 cfs @ 12.22 hrs, Volume= 0.253 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 5Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7,657 sf Runoff Depth=2.01"Subcatchment EX-1A: Subcatchment 1A Flow Length=94' Tc=5.1 min CN=69 Runoff=0.42 cfs 0.029 af
Runoff Area=222,696 sf Runoff Depth=1.85"Subcatchment EX-1B: Subcatchment 1B Flow Length=349' Tc=5.7 min CN=67 Runoff=10.87 cfs 0.788 af
Runoff Area=206,683 sf Runoff Depth=1.77"Subcatchment EX-2A: Subcatchment 2A Flow Length=413' Tc=13.2 min CN=66 Runoff=7.49 cfs 0.700 af
Inflow=11.28 cfs 0.817 afLink EX-NORTH: Existing BVW - North Primary=11.28 cfs 0.817 af
Inflow=7.49 cfs 0.700 afLink EX-SOUTH: Existing BVW - South Primary=7.49 cfs 0.700 af
Total Runoff Area = 10.033 ac Runoff Volume = 1.517 af Average Runoff Depth = 1.81"
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 6Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-1A: Subcatchment 1A
Runoff = 0.42 cfs @ 12.08 hrs, Volume= 0.029 af, Depth= 2.01"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description6,659 70 Woods, Good, HSG C
998 65 Brush, Good, HSG C7,657 69 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.7 25 0.1000 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.3 61 0.0246 0.8 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
0.1 8 0.2410 2.5 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
5.1 94 Total
Subcatchment EX-1B: Subcatchment 1B
Runoff = 10.87 cfs @ 12.09 hrs, Volume= 0.788 af, Depth= 1.85"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description114,305 65 Brush, Good, HSG C108,391 70 Woods, Good, HSG C222,696 67 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.1 50 0.0100 0.3 Sheet Flow, Fallow n= 0.050 P2= 3.20"
0.9 133 0.1243 2.5 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.4 38 0.0526 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
1.0 99 0.0606 1.7 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.3 29 0.0517 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
5.7 349 Total
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 7Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-2A: Subcatchment 2A
Runoff = 7.49 cfs @ 12.19 hrs, Volume= 0.700 af, Depth= 1.77"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description35,995 70 Woods, Good, HSG C
170,688 65 Brush, Good, HSG C206,683 66 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
6.2 50 0.1100 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.1 83 0.0602 1.2 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.6 67 0.0075 0.4 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
1.0 75 0.0670 1.3 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.3 138 0.0399 1.0 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
13.2 413 Total
Link EX-NORTH: Existing BVW - North
Inflow Area = 5.288 ac, Inflow Depth = 1.85" for 10-year event eventInflow = 11.28 cfs @ 12.09 hrs, Volume= 0.817 afPrimary = 11.28 cfs @ 12.09 hrs, Volume= 0.817 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link EX-SOUTH: Existing BVW - South
Inflow Area = 4.745 ac, Inflow Depth = 1.77" for 10-year event eventInflow = 7.49 cfs @ 12.19 hrs, Volume= 0.700 afPrimary = 7.49 cfs @ 12.19 hrs, Volume= 0.700 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 8Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7,657 sf Runoff Depth=2.90"Subcatchment EX-1A: Subcatchment 1A Flow Length=94' Tc=5.1 min CN=69 Runoff=0.61 cfs 0.042 af
Runoff Area=222,696 sf Runoff Depth=2.71"Subcatchment EX-1B: Subcatchment 1B Flow Length=349' Tc=5.7 min CN=67 Runoff=16.26 cfs 1.154 af
Runoff Area=206,683 sf Runoff Depth=2.61"Subcatchment EX-2A: Subcatchment 2A Flow Length=413' Tc=13.2 min CN=66 Runoff=11.37 cfs 1.033 af
Inflow=16.87 cfs 1.197 afLink EX-NORTH: Existing BVW - North Primary=16.87 cfs 1.197 af
Inflow=11.37 cfs 1.033 afLink EX-SOUTH: Existing BVW - South Primary=11.37 cfs 1.033 af
Total Runoff Area = 10.033 ac Runoff Volume = 2.229 af Average Runoff Depth = 2.67"
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 9Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-1A: Subcatchment 1A
Runoff = 0.61 cfs @ 12.08 hrs, Volume= 0.042 af, Depth= 2.90"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description6,659 70 Woods, Good, HSG C
998 65 Brush, Good, HSG C7,657 69 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.7 25 0.1000 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.3 61 0.0246 0.8 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
0.1 8 0.2410 2.5 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
5.1 94 Total
Subcatchment EX-1B: Subcatchment 1B
Runoff = 16.26 cfs @ 12.09 hrs, Volume= 1.154 af, Depth= 2.71"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description114,305 65 Brush, Good, HSG C108,391 70 Woods, Good, HSG C222,696 67 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.1 50 0.0100 0.3 Sheet Flow, Fallow n= 0.050 P2= 3.20"
0.9 133 0.1243 2.5 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.4 38 0.0526 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
1.0 99 0.0606 1.7 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.3 29 0.0517 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
5.7 349 Total
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 10Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-2A: Subcatchment 2A
Runoff = 11.37 cfs @ 12.19 hrs, Volume= 1.033 af, Depth= 2.61"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description35,995 70 Woods, Good, HSG C
170,688 65 Brush, Good, HSG C206,683 66 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
6.2 50 0.1100 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.1 83 0.0602 1.2 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.6 67 0.0075 0.4 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
1.0 75 0.0670 1.3 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.3 138 0.0399 1.0 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
13.2 413 Total
Link EX-NORTH: Existing BVW - North
Inflow Area = 5.288 ac, Inflow Depth = 2.72" for 25-year event eventInflow = 16.87 cfs @ 12.09 hrs, Volume= 1.197 afPrimary = 16.87 cfs @ 12.09 hrs, Volume= 1.197 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link EX-SOUTH: Existing BVW - South
Inflow Area = 4.745 ac, Inflow Depth = 2.61" for 25-year event eventInflow = 11.37 cfs @ 12.19 hrs, Volume= 1.033 afPrimary = 11.37 cfs @ 12.19 hrs, Volume= 1.033 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 11Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=7,657 sf Runoff Depth=4.39"Subcatchment EX-1A: Subcatchment 1A Flow Length=94' Tc=5.1 min CN=69 Runoff=0.94 cfs 0.064 af
Runoff Area=222,696 sf Runoff Depth=4.16"Subcatchment EX-1B: Subcatchment 1B Flow Length=349' Tc=5.7 min CN=67 Runoff=25.21 cfs 1.771 af
Runoff Area=206,683 sf Runoff Depth=4.04"Subcatchment EX-2A: Subcatchment 2A Flow Length=413' Tc=13.2 min CN=66 Runoff=17.84 cfs 1.596 af
Inflow=26.14 cfs 1.836 afLink EX-NORTH: Existing BVW - North Primary=26.14 cfs 1.836 af
Inflow=17.84 cfs 1.596 afLink EX-SOUTH: Existing BVW - South Primary=17.84 cfs 1.596 af
Total Runoff Area = 10.033 ac Runoff Volume = 3.432 af Average Runoff Depth = 4.10"
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 12Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-1A: Subcatchment 1A
Runoff = 0.94 cfs @ 12.08 hrs, Volume= 0.064 af, Depth= 4.39"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description6,659 70 Woods, Good, HSG C
998 65 Brush, Good, HSG C7,657 69 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.7 25 0.1000 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.3 61 0.0246 0.8 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
0.1 8 0.2410 2.5 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
5.1 94 Total
Subcatchment EX-1B: Subcatchment 1B
Runoff = 25.21 cfs @ 12.09 hrs, Volume= 1.771 af, Depth= 4.16"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description114,305 65 Brush, Good, HSG C108,391 70 Woods, Good, HSG C222,696 67 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
3.1 50 0.0100 0.3 Sheet Flow, Fallow n= 0.050 P2= 3.20"
0.9 133 0.1243 2.5 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.4 38 0.0526 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
1.0 99 0.0606 1.7 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
0.3 29 0.0517 1.6 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps
5.7 349 Total
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 13Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment EX-2A: Subcatchment 2A
Runoff = 17.84 cfs @ 12.19 hrs, Volume= 1.596 af, Depth= 4.04"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description35,995 70 Woods, Good, HSG C
170,688 65 Brush, Good, HSG C206,683 66 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
6.2 50 0.1100 0.1 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.20"
1.1 83 0.0602 1.2 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.6 67 0.0075 0.4 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
1.0 75 0.0670 1.3 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
2.3 138 0.0399 1.0 Shallow Concentrated Flow, Woodland Kv= 5.0 fps
13.2 413 Total
Link EX-NORTH: Existing BVW - North
Inflow Area = 5.288 ac, Inflow Depth = 4.17" for 100-year event eventInflow = 26.14 cfs @ 12.09 hrs, Volume= 1.836 afPrimary = 26.14 cfs @ 12.09 hrs, Volume= 1.836 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link EX-SOUTH: Existing BVW - South
Inflow Area = 4.745 ac, Inflow Depth = 4.04" for 100-year event eventInflow = 17.84 cfs @ 12.19 hrs, Volume= 1.596 afPrimary = 17.84 cfs @ 12.19 hrs, Volume= 1.596 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Drainage Diagram for HydrologyPrepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcat Reach Pond Link
PR-1A
Subcatchment PR-1A
PR-1B
Subcatchment PR-1B
PR-1C
Drainage to Infiltration System #1
PR-2A
Drainage to Infiltration System #2
PR-2B
Subcatchment PR-2B
PR-I--2
Infiltration #2
PR-I-1
Infiltration #1
PR-NORTH
Proposed BVW - North
PR-SOUTH
Proposed BVW - South
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 2Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=3,058 sf Runoff Depth=1.40"Subcatchment PR-1A: Subcatchment PR-1A Tc=5.0 min CN=80 Runoff=0.12 cfs 0.008 af
Runoff Area=68,144 sf Runoff Depth=0.93"Subcatchment PR-1B: Subcatchment PR-1B Tc=5.0 min CN=72 Runoff=1.64 cfs 0.121 af
Runoff Area=278,080 sf Runoff Depth=2.97"Subcatchment PR-1C: Drainage to Infiltration System #1 Tc=5.0 min CN=98 Runoff=20.54 cfs 1.578 af
Runoff Area=18,046 sf Runoff Depth=2.97"Subcatchment PR-2A: Drainage to Infiltration System #2 Tc=5.0 min CN=98 Runoff=1.33 cfs 0.102 af
Runoff Area=61,016 sf Runoff Depth=0.93"Subcatchment PR-2B: Subcatchment PR-2B Tc=5.0 min CN=72 Runoff=1.46 cfs 0.108 af
Peak Elev=67.28' Storage=567 cf Inflow=1.33 cfs 0.102 afPond PR-I--2: Infiltration #2 Discarded=0.00 cfs 0.000 af Primary=0.83 cfs 0.100 af Outflow=0.83 cfs 0.100 af
Peak Elev=57.74' Storage=34,275 cf Inflow=20.54 cfs 1.578 afPond PR-I-1: Infiltration #1 Discarded=0.11 cfs 0.188 af Primary=3.08 cfs 1.225 af Outflow=3.19 cfs 1.413 af
Inflow=3.55 cfs 1.354 afLink PR-NORTH: Proposed BVW - North Primary=3.55 cfs 1.354 af
Inflow=2.21 cfs 0.208 afLink PR-SOUTH: Proposed BVW - South Primary=2.21 cfs 0.208 af
Total Runoff Area = 9.833 ac Runoff Volume = 1.918 af Average Runoff Depth = 2.34"
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 3Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-1A: Subcatchment PR-1A
Runoff = 0.12 cfs @ 12.08 hrs, Volume= 0.008 af, Depth= 1.40"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description2,276 74 >75% Grass cover, Good, HSG C
782 98 Paved parking & roofs3,058 80 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1B: Subcatchment PR-1B
Runoff = 1.64 cfs @ 12.08 hrs, Volume= 0.121 af, Depth= 0.93"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description39,225 74 >75% Grass cover, Good, HSG C28,919 70 Woods, Good, HSG C68,144 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1C: Drainage to Infiltration System #1
Runoff = 20.54 cfs @ 12.07 hrs, Volume= 1.578 af, Depth= 2.97"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description278,080 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 4Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-2A: Drainage to Infiltration System #2
Runoff = 1.33 cfs @ 12.07 hrs, Volume= 0.102 af, Depth= 2.97"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description18,046 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-2B: Subcatchment PR-2B
Runoff = 1.46 cfs @ 12.08 hrs, Volume= 0.108 af, Depth= 0.93"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 2-year event Rainfall=3.20"
Area (sf) CN Description23,345 70 Woods, Good, HSG C37,671 74 >75% Grass cover, Good, HSG C61,016 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Pond PR-I--2: Infiltration #2
Inflow Area = 0.414 ac, Inflow Depth = 2.97" for 2-year event eventInflow = 1.33 cfs @ 12.07 hrs, Volume= 0.102 afOutflow = 0.83 cfs @ 12.16 hrs, Volume= 0.100 af, Atten= 38%, Lag= 5.4 minDiscarded = 0.00 cfs @ 0.00 hrs, Volume= 0.000 afPrimary = 0.83 cfs @ 12.16 hrs, Volume= 0.100 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 67.28' @ 12.16 hrs Surf.Area= 414 sf Storage= 567 cfPlug-Flow detention time= 32.8 min calculated for 0.100 af (98% of inflow)Center-of-Mass det. time= 18.6 min ( 773.6 - 755.0 )
# Invert Avail.Storage Storage Description1 65.00' 472 cf Custom Stage Data (Prismatic) Listed below
1,553 cf Overall - 373 cf Embedded = 1,180 cf x 40.0% Voids2 65.50' 373 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 8 Inside #1
845 cf Total Available Storage
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 5Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)65.00 414 0 068.75 414 1,553 1,553
# Routing Invert Outlet Devices1 Primary 65.50' 18.0" x 80.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 64.00' S= 0.0187 '/' n= 0.011 Cc= 0.900 2 Discarded 65.00' 0.003750 fpm Exfiltration over Surface area above invert 3 Device 1 65.50' 5.0" Vert. Orifice/Grate C= 0.600 4 Device 1 67.25' 12.0" Vert. Orifice/Grate C= 0.600 5 Device 1 68.50' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.00 cfs @ 0.00 hrs HW=65.00' (Free Discharge)2=Exfiltration ( Controls 0.00 cfs)
Primary OutFlow Max=0.83 cfs @ 12.16 hrs HW=67.28' (Free Discharge)1=Culvert (Passes 0.83 cfs of 6.81 cfs potential flow)
3=Orifice/Grate (Orifice Controls 0.82 cfs @ 6.0 fps)4=Orifice/Grate (Orifice Controls 0.00 cfs @ 0.6 fps)5=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond PR-I-1: Infiltration #1
Inflow Area = 6.384 ac, Inflow Depth = 2.97" for 2-year event eventInflow = 20.54 cfs @ 12.07 hrs, Volume= 1.578 afOutflow = 3.19 cfs @ 12.54 hrs, Volume= 1.413 af, Atten= 84%, Lag= 28.0 minDiscarded = 0.11 cfs @ 4.61 hrs, Volume= 0.188 afPrimary = 3.08 cfs @ 12.54 hrs, Volume= 1.225 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 57.74' @ 12.54 hrs Surf.Area= 18,225 sf Storage= 34,275 cfPlug-Flow detention time= 203.9 min calculated for 1.412 af (90% of inflow)Center-of-Mass det. time= 153.1 min ( 908.1 - 755.0 )
# Invert Avail.Storage Storage Description1 55.00' 41,251 cf Custom Stage Data (Prismatic) Listed below
127,575 cf Overall - 24,449 cf Embedded = 103,126 cf x 40.0% Voids2 55.50' 24,449 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 525 Inside #1
65,699 cf Total Available Storage
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)55.00 18,225 0 062.00 18,225 127,575 127,575
Type III 24-hr 2-year event Rainfall=3.20"HydrologyPage 6Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
# Routing Invert Outlet Devices1 Primary 55.50' 24.0" x 12.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 54.50' S= 0.0833 '/' n= 0.011 Cc= 0.900 2 Discarded 55.00' 0.11 cfs Exfiltration when above invert 3 Device 1 55.50' 8.0" Vert. Orifice/Grate C= 0.600 4 Device 1 57.40' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 5 Device 1 59.50' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 6 Device 1 61.00' 9.0" Vert. Orifice/Grate C= 0.600 7 Device 1 62.00' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.11 cfs @ 4.61 hrs HW=55.07' (Free Discharge)2=Exfiltration (Exfiltration Controls 0.11 cfs)
Primary OutFlow Max=3.08 cfs @ 12.54 hrs HW=57.74' (Free Discharge)1=Culvert (Passes 3.08 cfs of 13.28 cfs potential flow)
3=Orifice/Grate (Orifice Controls 2.32 cfs @ 6.6 fps)4=Orifice/Grate (Orifice Controls 0.76 cfs @ 2.0 fps)5=Orifice/Grate ( Controls 0.00 cfs)6=Orifice/Grate ( Controls 0.00 cfs)7=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Link PR-NORTH: Proposed BVW - North
Inflow Area = 8.018 ac, Inflow Depth = 2.03" for 2-year event eventInflow = 3.55 cfs @ 12.10 hrs, Volume= 1.354 afPrimary = 3.55 cfs @ 12.10 hrs, Volume= 1.354 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link PR-SOUTH: Proposed BVW - South
Inflow Area = 1.815 ac, Inflow Depth = 1.38" for 2-year event eventInflow = 2.21 cfs @ 12.09 hrs, Volume= 0.208 afPrimary = 2.21 cfs @ 12.09 hrs, Volume= 0.208 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 7Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=3,058 sf Runoff Depth=2.95"Subcatchment PR-1A: Subcatchment PR-1A Tc=5.0 min CN=80 Runoff=0.25 cfs 0.017 af
Runoff Area=68,144 sf Runoff Depth=2.25"Subcatchment PR-1B: Subcatchment PR-1B Tc=5.0 min CN=72 Runoff=4.24 cfs 0.293 af
Runoff Area=278,080 sf Runoff Depth=4.83"Subcatchment PR-1C: Drainage to Infiltration System #1 Tc=5.0 min CN=98 Runoff=32.81 cfs 2.569 af
Runoff Area=18,046 sf Runoff Depth=4.83"Subcatchment PR-2A: Drainage to Infiltration System #2 Tc=5.0 min CN=98 Runoff=2.13 cfs 0.167 af
Runoff Area=61,016 sf Runoff Depth=2.25"Subcatchment PR-2B: Subcatchment PR-2B Tc=5.0 min CN=72 Runoff=3.80 cfs 0.263 af
Peak Elev=67.79' Storage=683 cf Inflow=2.13 cfs 0.167 afPond PR-I--2: Infiltration #2 Discarded=0.00 cfs 0.000 af Primary=2.05 cfs 0.164 af Outflow=2.05 cfs 0.164 af
Peak Elev=59.53' Storage=47,722 cf Inflow=32.81 cfs 2.569 afPond PR-I-1: Infiltration #1 Discarded=0.11 cfs 0.199 af Primary=8.89 cfs 2.175 af Outflow=9.00 cfs 2.374 af
Inflow=10.89 cfs 2.485 afLink PR-NORTH: Proposed BVW - North Primary=10.89 cfs 2.485 af
Inflow=5.82 cfs 0.427 afLink PR-SOUTH: Proposed BVW - South Primary=5.82 cfs 0.427 af
Total Runoff Area = 9.833 ac Runoff Volume = 3.309 af Average Runoff Depth = 4.04"
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 8Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-1A: Subcatchment PR-1A
Runoff = 0.25 cfs @ 12.07 hrs, Volume= 0.017 af, Depth= 2.95"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description2,276 74 >75% Grass cover, Good, HSG C
782 98 Paved parking & roofs3,058 80 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1B: Subcatchment PR-1B
Runoff = 4.24 cfs @ 12.08 hrs, Volume= 0.293 af, Depth= 2.25"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description39,225 74 >75% Grass cover, Good, HSG C28,919 70 Woods, Good, HSG C68,144 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1C: Drainage to Infiltration System #1
Runoff = 32.81 cfs @ 12.07 hrs, Volume= 2.569 af, Depth= 4.83"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description278,080 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 9Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-2A: Drainage to Infiltration System #2
Runoff = 2.13 cfs @ 12.07 hrs, Volume= 0.167 af, Depth= 4.83"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description18,046 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-2B: Subcatchment PR-2B
Runoff = 3.80 cfs @ 12.08 hrs, Volume= 0.263 af, Depth= 2.25"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 10-year event Rainfall=5.07"
Area (sf) CN Description23,345 70 Woods, Good, HSG C37,671 74 >75% Grass cover, Good, HSG C61,016 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Pond PR-I--2: Infiltration #2
Inflow Area = 0.414 ac, Inflow Depth = 4.83" for 10-year event eventInflow = 2.13 cfs @ 12.07 hrs, Volume= 0.167 afOutflow = 2.05 cfs @ 12.09 hrs, Volume= 0.164 af, Atten= 4%, Lag= 1.3 minDiscarded = 0.00 cfs @ 0.00 hrs, Volume= 0.000 afPrimary = 2.05 cfs @ 12.09 hrs, Volume= 0.164 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 67.79' @ 12.09 hrs Surf.Area= 414 sf Storage= 683 cfPlug-Flow detention time= 24.0 min calculated for 0.164 af (99% of inflow)Center-of-Mass det. time= 14.4 min ( 760.8 - 746.4 )
# Invert Avail.Storage Storage Description1 65.00' 472 cf Custom Stage Data (Prismatic) Listed below
1,553 cf Overall - 373 cf Embedded = 1,180 cf x 40.0% Voids2 65.50' 373 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 8 Inside #1
845 cf Total Available Storage
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 10Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)65.00 414 0 068.75 414 1,553 1,553
# Routing Invert Outlet Devices1 Primary 65.50' 18.0" x 80.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 64.00' S= 0.0187 '/' n= 0.011 Cc= 0.900 2 Discarded 65.00' 0.003750 fpm Exfiltration over Surface area above invert 3 Device 1 65.50' 5.0" Vert. Orifice/Grate C= 0.600 4 Device 1 67.25' 12.0" Vert. Orifice/Grate C= 0.600 5 Device 1 68.50' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.00 cfs @ 0.00 hrs HW=65.00' (Free Discharge)2=Exfiltration ( Controls 0.00 cfs)
Primary OutFlow Max=2.04 cfs @ 12.09 hrs HW=67.79' (Free Discharge)1=Culvert (Passes 2.04 cfs of 8.34 cfs potential flow)
3=Orifice/Grate (Orifice Controls 0.95 cfs @ 7.0 fps)4=Orifice/Grate (Orifice Controls 1.09 cfs @ 2.5 fps)5=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond PR-I-1: Infiltration #1
Inflow Area = 6.384 ac, Inflow Depth = 4.83" for 10-year event eventInflow = 32.81 cfs @ 12.07 hrs, Volume= 2.569 afOutflow = 9.00 cfs @ 12.40 hrs, Volume= 2.374 af, Atten= 73%, Lag= 19.7 minDiscarded = 0.11 cfs @ 2.92 hrs, Volume= 0.199 afPrimary = 8.89 cfs @ 12.40 hrs, Volume= 2.175 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 59.53' @ 12.40 hrs Surf.Area= 18,225 sf Storage= 47,722 cfPlug-Flow detention time= 168.1 min calculated for 2.374 af (92% of inflow)Center-of-Mass det. time= 127.3 min ( 873.8 - 746.4 )
# Invert Avail.Storage Storage Description1 55.00' 41,251 cf Custom Stage Data (Prismatic) Listed below
127,575 cf Overall - 24,449 cf Embedded = 103,126 cf x 40.0% Voids2 55.50' 24,449 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 525 Inside #1
65,699 cf Total Available Storage
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)55.00 18,225 0 062.00 18,225 127,575 127,575
Type III 24-hr 10-year event Rainfall=5.07"HydrologyPage 11Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
# Routing Invert Outlet Devices1 Primary 55.50' 24.0" x 12.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 54.50' S= 0.0833 '/' n= 0.011 Cc= 0.900 2 Discarded 55.00' 0.11 cfs Exfiltration when above invert 3 Device 1 55.50' 8.0" Vert. Orifice/Grate C= 0.600 4 Device 1 57.40' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 5 Device 1 59.50' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 6 Device 1 61.00' 9.0" Vert. Orifice/Grate C= 0.600 7 Device 1 62.00' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.11 cfs @ 2.92 hrs HW=55.07' (Free Discharge)2=Exfiltration (Exfiltration Controls 0.11 cfs)
Primary OutFlow Max=8.88 cfs @ 12.40 hrs HW=59.53' (Free Discharge)1=Culvert (Passes 8.88 cfs of 20.80 cfs potential flow)
3=Orifice/Grate (Orifice Controls 3.23 cfs @ 9.3 fps)4=Orifice/Grate (Orifice Controls 5.64 cfs @ 6.4 fps)5=Orifice/Grate (Orifice Controls 0.01 cfs @ 0.6 fps)6=Orifice/Grate ( Controls 0.00 cfs)7=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Link PR-NORTH: Proposed BVW - North
Inflow Area = 8.018 ac, Inflow Depth = 3.72" for 10-year event eventInflow = 10.89 cfs @ 12.13 hrs, Volume= 2.485 afPrimary = 10.89 cfs @ 12.13 hrs, Volume= 2.485 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link PR-SOUTH: Proposed BVW - South
Inflow Area = 1.815 ac, Inflow Depth = 2.82" for 10-year event eventInflow = 5.82 cfs @ 12.08 hrs, Volume= 0.427 afPrimary = 5.82 cfs @ 12.08 hrs, Volume= 0.427 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 12Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=3,058 sf Runoff Depth=3.99"Subcatchment PR-1A: Subcatchment PR-1A Tc=5.0 min CN=80 Runoff=0.34 cfs 0.023 af
Runoff Area=68,144 sf Runoff Depth=3.19"Subcatchment PR-1B: Subcatchment PR-1B Tc=5.0 min CN=72 Runoff=6.06 cfs 0.416 af
Runoff Area=278,080 sf Runoff Depth=6.00"Subcatchment PR-1C: Drainage to Infiltration System #1 Tc=5.0 min CN=98 Runoff=40.45 cfs 3.191 af
Runoff Area=18,046 sf Runoff Depth=6.00"Subcatchment PR-2A: Drainage to Infiltration System #2 Tc=5.0 min CN=98 Runoff=2.63 cfs 0.207 af
Runoff Area=61,016 sf Runoff Depth=3.19"Subcatchment PR-2B: Subcatchment PR-2B Tc=5.0 min CN=72 Runoff=5.43 cfs 0.372 af
Peak Elev=67.93' Storage=709 cf Inflow=2.63 cfs 0.207 afPond PR-I--2: Infiltration #2 Discarded=0.00 cfs 0.000 af Primary=2.58 cfs 0.205 af Outflow=2.58 cfs 0.205 af
Peak Elev=60.51' Storage=54,818 cf Inflow=40.45 cfs 3.191 afPond PR-I-1: Infiltration #1 Discarded=0.11 cfs 0.203 af Primary=14.05 cfs 2.774 af Outflow=14.16 cfs 2.977 af
Inflow=16.85 cfs 3.213 afLink PR-NORTH: Proposed BVW - North Primary=16.85 cfs 3.213 af
Inflow=8.00 cfs 0.577 afLink PR-SOUTH: Proposed BVW - South Primary=8.00 cfs 0.577 af
Total Runoff Area = 9.833 ac Runoff Volume = 4.209 af Average Runoff Depth = 5.14"
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 13Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-1A: Subcatchment PR-1A
Runoff = 0.34 cfs @ 12.07 hrs, Volume= 0.023 af, Depth= 3.99"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description2,276 74 >75% Grass cover, Good, HSG C
782 98 Paved parking & roofs3,058 80 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1B: Subcatchment PR-1B
Runoff = 6.06 cfs @ 12.08 hrs, Volume= 0.416 af, Depth= 3.19"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description39,225 74 >75% Grass cover, Good, HSG C28,919 70 Woods, Good, HSG C68,144 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1C: Drainage to Infiltration System #1
Runoff = 40.45 cfs @ 12.07 hrs, Volume= 3.191 af, Depth= 6.00"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description278,080 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 14Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-2A: Drainage to Infiltration System #2
Runoff = 2.63 cfs @ 12.07 hrs, Volume= 0.207 af, Depth= 6.00"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description18,046 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-2B: Subcatchment PR-2B
Runoff = 5.43 cfs @ 12.08 hrs, Volume= 0.372 af, Depth= 3.19"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 25-year event Rainfall=6.24"
Area (sf) CN Description23,345 70 Woods, Good, HSG C37,671 74 >75% Grass cover, Good, HSG C61,016 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Pond PR-I--2: Infiltration #2
Inflow Area = 0.414 ac, Inflow Depth = 6.00" for 25-year event eventInflow = 2.63 cfs @ 12.07 hrs, Volume= 0.207 afOutflow = 2.58 cfs @ 12.08 hrs, Volume= 0.205 af, Atten= 2%, Lag= 0.8 minDiscarded = 0.00 cfs @ 0.00 hrs, Volume= 0.000 afPrimary = 2.58 cfs @ 12.08 hrs, Volume= 0.205 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 67.93' @ 12.08 hrs Surf.Area= 414 sf Storage= 709 cfPlug-Flow detention time= 20.7 min calculated for 0.204 af (99% of inflow)Center-of-Mass det. time= 12.7 min ( 755.9 - 743.2 )
# Invert Avail.Storage Storage Description1 65.00' 472 cf Custom Stage Data (Prismatic) Listed below
1,553 cf Overall - 373 cf Embedded = 1,180 cf x 40.0% Voids2 65.50' 373 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 8 Inside #1
845 cf Total Available Storage
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 15Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)65.00 414 0 068.75 414 1,553 1,553
# Routing Invert Outlet Devices1 Primary 65.50' 18.0" x 80.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 64.00' S= 0.0187 '/' n= 0.011 Cc= 0.900 2 Discarded 65.00' 0.003750 fpm Exfiltration over Surface area above invert 3 Device 1 65.50' 5.0" Vert. Orifice/Grate C= 0.600 4 Device 1 67.25' 12.0" Vert. Orifice/Grate C= 0.600 5 Device 1 68.50' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.00 cfs @ 0.00 hrs HW=65.00' (Free Discharge)2=Exfiltration ( Controls 0.00 cfs)
Primary OutFlow Max=2.58 cfs @ 12.08 hrs HW=67.93' (Free Discharge)1=Culvert (Passes 2.58 cfs of 8.71 cfs potential flow)
3=Orifice/Grate (Orifice Controls 0.98 cfs @ 7.2 fps)4=Orifice/Grate (Orifice Controls 1.60 cfs @ 2.8 fps)5=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond PR-I-1: Infiltration #1
Inflow Area = 6.384 ac, Inflow Depth = 6.00" for 25-year event eventInflow = 40.45 cfs @ 12.07 hrs, Volume= 3.191 afOutflow = 14.16 cfs @ 12.31 hrs, Volume= 2.977 af, Atten= 65%, Lag= 14.5 minDiscarded = 0.11 cfs @ 2.34 hrs, Volume= 0.203 afPrimary = 14.05 cfs @ 12.31 hrs, Volume= 2.774 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 60.51' @ 12.31 hrs Surf.Area= 18,225 sf Storage= 54,818 cfPlug-Flow detention time= 153.5 min calculated for 2.976 af (93% of inflow)Center-of-Mass det. time= 116.5 min ( 859.7 - 743.2 )
# Invert Avail.Storage Storage Description1 55.00' 41,251 cf Custom Stage Data (Prismatic) Listed below
127,575 cf Overall - 24,449 cf Embedded = 103,126 cf x 40.0% Voids2 55.50' 24,449 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 525 Inside #1
65,699 cf Total Available Storage
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)55.00 18,225 0 062.00 18,225 127,575 127,575
Type III 24-hr 25-year event Rainfall=6.24"HydrologyPage 16Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
# Routing Invert Outlet Devices1 Primary 55.50' 24.0" x 12.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 54.50' S= 0.0833 '/' n= 0.011 Cc= 0.900 2 Discarded 55.00' 0.11 cfs Exfiltration when above invert 3 Device 1 55.50' 8.0" Vert. Orifice/Grate C= 0.600 4 Device 1 57.40' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 5 Device 1 59.50' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 6 Device 1 61.00' 9.0" Vert. Orifice/Grate C= 0.600 7 Device 1 62.00' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.11 cfs @ 2.34 hrs HW=55.07' (Free Discharge)2=Exfiltration (Exfiltration Controls 0.11 cfs)
Primary OutFlow Max=14.05 cfs @ 12.31 hrs HW=60.51' (Free Discharge)1=Culvert (Passes 14.05 cfs of 23.91 cfs potential flow)
3=Orifice/Grate (Orifice Controls 3.63 cfs @ 10.4 fps)4=Orifice/Grate (Orifice Controls 7.03 cfs @ 8.0 fps)5=Orifice/Grate (Orifice Controls 3.38 cfs @ 3.8 fps)6=Orifice/Grate ( Controls 0.00 cfs)7=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Link PR-NORTH: Proposed BVW - North
Inflow Area = 8.018 ac, Inflow Depth = 4.81" for 25-year event eventInflow = 16.85 cfs @ 12.23 hrs, Volume= 3.213 afPrimary = 16.85 cfs @ 12.23 hrs, Volume= 3.213 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link PR-SOUTH: Proposed BVW - South
Inflow Area = 1.815 ac, Inflow Depth = 3.81" for 25-year event eventInflow = 8.00 cfs @ 12.08 hrs, Volume= 0.577 afPrimary = 8.00 cfs @ 12.08 hrs, Volume= 0.577 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 17Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 pointsRunoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Runoff Area=3,058 sf Runoff Depth=5.67"Subcatchment PR-1A: Subcatchment PR-1A Tc=5.0 min CN=80 Runoff=0.48 cfs 0.033 af
Runoff Area=68,144 sf Runoff Depth=4.73"Subcatchment PR-1B: Subcatchment PR-1B Tc=5.0 min CN=72 Runoff=9.01 cfs 0.617 af
Runoff Area=278,080 sf Runoff Depth=7.81"Subcatchment PR-1C: Drainage to Infiltration System #1 Tc=5.0 min CN=98 Runoff=52.27 cfs 4.152 af
Runoff Area=18,046 sf Runoff Depth=7.81"Subcatchment PR-2A: Drainage to Infiltration System #2 Tc=5.0 min CN=98 Runoff=3.39 cfs 0.269 af
Runoff Area=61,016 sf Runoff Depth=4.73"Subcatchment PR-2B: Subcatchment PR-2B Tc=5.0 min CN=72 Runoff=8.06 cfs 0.553 af
Peak Elev=68.13' Storage=741 cf Inflow=3.39 cfs 0.269 afPond PR-I--2: Infiltration #2 Discarded=0.00 cfs 0.000 af Primary=3.34 cfs 0.267 af Outflow=3.34 cfs 0.267 af
Peak Elev=61.97' Storage=65,476 cf Inflow=52.27 cfs 4.152 afPond PR-I-1: Infiltration #1 Discarded=0.11 cfs 0.206 af Primary=20.67 cfs 3.703 af Outflow=20.78 cfs 3.910 af
Inflow=25.96 cfs 4.354 afLink PR-NORTH: Proposed BVW - North Primary=25.96 cfs 4.354 af
Inflow=11.39 cfs 0.819 afLink PR-SOUTH: Proposed BVW - South Primary=11.39 cfs 0.819 af
Total Runoff Area = 9.833 ac Runoff Volume = 5.625 af Average Runoff Depth = 6.86"
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 18Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-1A: Subcatchment PR-1A
Runoff = 0.48 cfs @ 12.07 hrs, Volume= 0.033 af, Depth= 5.67"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description2,276 74 >75% Grass cover, Good, HSG C
782 98 Paved parking & roofs3,058 80 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1B: Subcatchment PR-1B
Runoff = 9.01 cfs @ 12.07 hrs, Volume= 0.617 af, Depth= 4.73"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description39,225 74 >75% Grass cover, Good, HSG C28,919 70 Woods, Good, HSG C68,144 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-1C: Drainage to Infiltration System #1
Runoff = 52.27 cfs @ 12.07 hrs, Volume= 4.152 af, Depth= 7.81"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description278,080 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 19Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Subcatchment PR-2A: Drainage to Infiltration System #2
Runoff = 3.39 cfs @ 12.07 hrs, Volume= 0.269 af, Depth= 7.81"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description18,046 98 Paved parking & roofs
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Subcatchment PR-2B: Subcatchment PR-2B
Runoff = 8.06 cfs @ 12.07 hrs, Volume= 0.553 af, Depth= 4.73"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.01 hrsType III 24-hr 100-year event Rainfall=8.05"
Area (sf) CN Description23,345 70 Woods, Good, HSG C37,671 74 >75% Grass cover, Good, HSG C61,016 72 Weighted Average
Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Tc (min)
Pond PR-I--2: Infiltration #2
Inflow Area = 0.414 ac, Inflow Depth = 7.81" for 100-year event eventInflow = 3.39 cfs @ 12.07 hrs, Volume= 0.269 afOutflow = 3.34 cfs @ 12.08 hrs, Volume= 0.267 af, Atten= 1%, Lag= 0.7 minDiscarded = 0.00 cfs @ 0.00 hrs, Volume= 0.000 afPrimary = 3.34 cfs @ 12.08 hrs, Volume= 0.267 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 68.13' @ 12.08 hrs Surf.Area= 414 sf Storage= 741 cfPlug-Flow detention time= 17.4 min calculated for 0.267 af (99% of inflow)Center-of-Mass det. time= 11.0 min ( 750.7 - 739.8 )
# Invert Avail.Storage Storage Description1 65.00' 472 cf Custom Stage Data (Prismatic) Listed below
1,553 cf Overall - 373 cf Embedded = 1,180 cf x 40.0% Voids2 65.50' 373 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 8 Inside #1
845 cf Total Available Storage
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 20Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)65.00 414 0 068.75 414 1,553 1,553
# Routing Invert Outlet Devices1 Primary 65.50' 18.0" x 80.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 64.00' S= 0.0187 '/' n= 0.011 Cc= 0.900 2 Discarded 65.00' 0.003750 fpm Exfiltration over Surface area above invert 3 Device 1 65.50' 5.0" Vert. Orifice/Grate C= 0.600 4 Device 1 67.25' 12.0" Vert. Orifice/Grate C= 0.600 5 Device 1 68.50' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.00 cfs @ 0.00 hrs HW=65.00' (Free Discharge)2=Exfiltration ( Controls 0.00 cfs)
Primary OutFlow Max=3.34 cfs @ 12.08 hrs HW=68.12' (Free Discharge)1=Culvert (Passes 3.34 cfs of 9.20 cfs potential flow)
3=Orifice/Grate (Orifice Controls 1.02 cfs @ 7.5 fps)4=Orifice/Grate (Orifice Controls 2.32 cfs @ 3.2 fps)5=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond PR-I-1: Infiltration #1
Inflow Area = 6.384 ac, Inflow Depth = 7.81" for 100-year event eventInflow = 52.27 cfs @ 12.07 hrs, Volume= 4.152 afOutflow = 20.78 cfs @ 12.26 hrs, Volume= 3.910 af, Atten= 60%, Lag= 11.6 minDiscarded = 0.11 cfs @ 1.76 hrs, Volume= 0.206 afPrimary = 20.67 cfs @ 12.26 hrs, Volume= 3.703 af
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs / 2Peak Elev= 61.97' @ 12.26 hrs Surf.Area= 18,225 sf Storage= 65,476 cfPlug-Flow detention time= 137.5 min calculated for 3.908 af (94% of inflow)Center-of-Mass det. time= 104.2 min ( 843.9 - 739.8 )
# Invert Avail.Storage Storage Description1 55.00' 41,251 cf Custom Stage Data (Prismatic) Listed below
127,575 cf Overall - 24,449 cf Embedded = 103,126 cf x 40.0% Voids2 55.50' 24,449 cf 47.8"W x 30.0"H x 6.25'L Cultec R-330 x 525 Inside #1
65,699 cf Total Available Storage
Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)55.00 18,225 0 062.00 18,225 127,575 127,575
Type III 24-hr 100-year event Rainfall=8.05"HydrologyPage 21Prepared by Dana F. Perkins, Inc.
HydroCAD® 7.00 s/n 000444 © 1986-2003 Applied Microcomputer Systems
# Routing Invert Outlet Devices1 Primary 55.50' 24.0" x 12.0' long Culvert CMP, projecting, no headwall, Ke= 0.900
Outlet Invert= 54.50' S= 0.0833 '/' n= 0.011 Cc= 0.900 2 Discarded 55.00' 0.11 cfs Exfiltration when above invert 3 Device 1 55.50' 8.0" Vert. Orifice/Grate C= 0.600 4 Device 1 57.40' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 5 Device 1 59.50' 9.0" Vert. Orifice/Grate X 2.00 C= 0.600 6 Device 1 61.00' 9.0" Vert. Orifice/Grate C= 0.600 7 Device 1 62.00' 4.0' long x 1.0' high Sharp-Crested Rectangular Weir
2 End Contraction(s)
Discarded OutFlow Max=0.11 cfs @ 1.76 hrs HW=55.07' (Free Discharge)2=Exfiltration (Exfiltration Controls 0.11 cfs)
Primary OutFlow Max=20.67 cfs @ 12.26 hrs HW=61.97' (Free Discharge)1=Culvert (Passes 20.67 cfs of 27.93 cfs potential flow)
3=Orifice/Grate (Orifice Controls 4.16 cfs @ 11.9 fps)4=Orifice/Grate (Orifice Controls 8.71 cfs @ 9.9 fps)5=Orifice/Grate (Orifice Controls 6.16 cfs @ 7.0 fps)6=Orifice/Grate (Orifice Controls 1.64 cfs @ 3.7 fps)7=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)
Link PR-NORTH: Proposed BVW - North
Inflow Area = 8.018 ac, Inflow Depth = 6.52" for 100-year event eventInflow = 25.96 cfs @ 12.14 hrs, Volume= 4.354 afPrimary = 25.96 cfs @ 12.14 hrs, Volume= 4.354 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Link PR-SOUTH: Proposed BVW - South
Inflow Area = 1.815 ac, Inflow Depth = 5.42" for 100-year event eventInflow = 11.39 cfs @ 12.08 hrs, Volume= 0.819 afPrimary = 11.39 cfs @ 12.08 hrs, Volume= 0.819 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs
Stormwater Management Permit
Proposed Trade School Facility Hilldale Avenue
Haverhill, Massachusetts
Hydraulic Calculations
Prepared for:
New England Tractor Trailer Training School 1600 Osgood Street, Unit 1570
North Andover, MA 01845
Prepared by:
Dana F. Perkins, Inc. 1057 East Street
Tewksbury, MA 01876
Submitted To: City of Haverhill ~ Planning Board
