Existing Erhart FarmRemoval percentage on an annual basis
BMP
TP & TSS Volume
Reduction
Particulate P
Removal Dissolved P Removal
Total P
Removal
TSS
Removal
Green roof 45%0%0%0%0%96%
Bioretention basin (w/o underdrain)Calculate from lookup table 100%0%0%0%0%
Bioretention basin (with underdrain)Calculate from lookup table 100%80%
Infiltration basin/Infiltration trench (aboveground)Calculate from lookup table 100%0%0%0%0%
Underground infiltration Calculate from lookup table 100%0%0%0%0%
Permeable pavement Calculate from lookup table 100%82%0%45%74%
Tree trench system/Box (w/o underdrain)Calculate from lookup table 0%0%0%0%
Tree trench system/Box (with underdrain)Calculate from lookup table 100%80%
Swale Side Slope Calculate from lookup table 100%
Swale main channel Calculate from lookup table 100%73%0%40%68%
Swale main channel (with underdrain)Calculate from lookup table 100%36%0%20%68%
Stormwater disconnection (Impervious
Disconnection)Calculate from lookup table 100%0%0%0%68%
Harvest and re-use/Cistern Calculate using simulation 100%0%0%0%0%
Wet swale 0%0%0%0%0%68%
Sand filter 0%0%85%Calculated based on design 47%85%
Constructed stormwater pond 0%0%
Constructed wetland 0%0%55%0%30%68%
Other User defined User defined User defined User defined User defined User defined
Sources
Calculated based on design parameters
Commonwealth of Virginia Runoff Reduction Method
MN Stormwater Manual
% Annual Runoff Volume
Retained (%RVR)
(Non-Volume Reduced Runoff)
% Pollutant Removal (%PR)
Calculated based on design
Calculated based on design
Removals applied to main channel component
Calculated based on design