Making Urban Trees Count: Pollutant Load Reduction Credit
CREDITING FRAMEWORK PRODUCT #3 of Making Urban Trees Count: A Project to Demonstrate the Role of Urban Trees in Achieving Regulatory Compliance for Clean Water
The Center for Watershed Protection developed a national Pollutant Load Reduction Credit for tree planting that can be adopted by regulatory entities who wish to offer a scientifically defensible credit that encourages greater use of trees for meeting total maximum daily load (TMDL) requirements. The credit quantifies an annual reduction in nutrient and sediment loads relative to the pollutant loading rate of the underlying land cover.
The Pollutant Load Reduction Credit was developed using a water balance model to estimate the mean annual runoff for a single tree at maturity planted over turf or impervious cover, compared to runoff from those same sites without trees. The model was run for the four
hydrologic soil groups (HSG) for five tree types at 31 locations in 11 climate zones.
Center for Watershed Protection
Best Management Practices (BMPs), Planting, Stormwater Management
ufs - drh