HomeMy WebLinkAboutSDP201500055 Calculations 2015-10-26 Nrow
Now
Virginia Runoff Reduction Method New Development Worksheet-v2.8 -June 2014
To be used w/2011 BMP Standards and Specifications
Site Data
Project Name:Sunset Overlook-Land Cover Area defined by Parcels Legal Limits
Date: 10/26/15
. , 1
�2',2:/^� � ���`.:22,2 1
data input cells
calculation cells
constant values
1. Post-Development Project& Land Cover Information
Constants
{
Annual nammn(mcheo) ^e^� ��`�
Target Rainfall Event(inches) 1.00
Phosphorus EMC(mg/L) 026 Nitrogen EMC(mg/L) 1.86
Target Phosphorus Target Load(Ib/acre/yr) 0.41
Pi 0.90
Land Cover (acres)
A soils B Soils C Soils D Soils Totals
Forest/Open Space(acres)--undisturbed, '
protected forest/open space reforested land �.99
Managed Turf(acres) disturbed graded for
yards or other turf to be mowed/managed ' $.08
Impervious Cover(acres)
Total 10.40
Rv Coefficients
xovn" ouvny cavoe ouons
Forest/Open Space 0.02 0.03 0.04 0.05
Managed Turf 0.15 020 022 025
impervious Cover 0.85 0.95 0.85 0.95
Land Cover Summary
Forest/Open Space Cover(acres) 1.89
we/ohmmnv(mreut) 0.03
%Forest 19%
Managed Turf Cov r(acres) 6.08
wo/noumnv(turf) 0.20
%Managed Turf 58%
Impervious Cover(acres) 2.33
Rv(impervious) 0.95
%/mnommu 22%
Total Site Area acres 10.40
Site Rv 0.34
Post-Development Treatment Volume(acre-ft) 0.29
'ou ^evoonmon rea men 'oumo nu^/c
feet) 12,666
po*_oovomnmvnt Load(Tp)(/mv,) 7.86 puoLoo,o/ovmont Load(Tw)(m/y, 56.9
Total Load(TP)Reduction Required(Ib/yr) 3.69 1
' ,
Virginia Runoff Reduction Method Worksheet
Virginia Runoff Reduction Method New Development Worksheet-v2.8-June 2014
Site Data Summary
Total Rainfall=43 inches
Site Land Cover Summary
A Soils B Soils C Soils D Soils Total %of Total
Forest(acres) 0.00 1.99 0.00 0.00 1.99 19.13
Turf(acres) 0.00 6.08 0.00 0.00 6.08 58.46
Impervious(acres) 0.00 2.33 0.00 0.00 2.33 22.40
10.40 100.00
Site Rv 0.34
Post Development Treatment Volume(ft3) 12666
Post Development TP Load(Ib/yr) 7.96
Post Development TN Load(Ib/yr) 56.93
Total TP Load Reduction Required(Ib/yr) 3.69
Total Runoff Volume Reduction(ft') 4408
Total TP Load Reduction Achieved(Ib/yr) 4
Total TN Load Reduction Achieved(Ib/yr) 49.47
Adjusted Post Development TP Load(Ib/yr) 4.15
Remaining Phosphorous Load Reduction(Lb/yr)Required 0.00
Drainage Area Summary
D.A.A D.A.B D.A.C D.A.D D.A.E Total
Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00
Turf(acres) 1.30 2.43 0.00 0.00 0.00 3.73
Impervious(acres) 1.45 0.96 0.00 0.00 0.00 2.41
6.14
Drainage Area Compliance Summary
D.A.A D.A.B D.A.C D.A.D D.A.E Total
TP Load Red.(Ib/yr) 2.05 1.75 0.00 0.00 0.00, 3.80
TN Load Red.(Ib/yr) 26.69 22.78 0.00 0.00 0.00 49.47
Summary Print
e
Virginia Runoff Reduction Method Worksheet
Drainage Area A Summary
Land Cover Summary
A Soils B Soils C Soils D Soils Total %of Total
Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00
Turf(acres) 0.00 1.30 0.00 0.00 1.30 47.27
Impervious(acres) 0.00 1.45 0.00 0.00 1.45 52.73
2.75
BMP Selections
Practice Credit Area(acres) Downstream
Practice
6.a.Bioretention#1 or Urban Bioretention(Spec#9) Impervious: I 1.45
Turf(Pervious): 1.3
Total Impervious Cover Treated(acres) 1.45
Total Turf Area Treated(acres) 1.30
Total TP Load Reduction Achieved in D.A.A(Ib/yr) 2.05
Total TN Load Reduction Achieved in D.A.A(Ib/yr) 26.69
Summary Print
NOW
Virginia Runoff Reduction Method Worksheet
Drainage Area B Summary
Land Cover Summary
A Soils B Soils C Soils D Soils Total %of Total
Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00
Turf(acres) 0.00 2.43 0.00 0.00 2.43 71.68
Impervious(acres) 0.00_ 0.96 0.00 0.00 0.96 28.32
3.39
BMP Selections
Practice Credit Area(acres) Downstream
Practice
6.a.Bioretention#1 or Urban Bioretention(Spec#9) Impervious: I 0.96
Turf(Pervious): 2.43
Total Impervious Cover Treated(acres) 0.96
Total Turf Area Treated(acres) 2.43
Total TP Load Reduction Achieved in D.A.A(Ib/yr) 1.75
Total TN Load Reduction Achieved in D.A.A(Ib/yr) 22.78
Summary Print