Oct. 25, 2018 Center for Watershed Protection Releases New Guidance Document

Accounting for Trees in Stormwater Models

In September of 2018 the Center for Watershed Protection released a new guidance document: Accounting for Trees in Stormwater Models

This paper is intended to help the stormwater management community account for trees in runoff and pollutant load calculations and incorporate them into stormwater management strategies. It summarizes existing hydrologic and hydraulic models that can be applied at the site and small watershed scales to highlight the benefits of conserving trees and/or planting new trees. The paper also includes examples of specific techniques to modify stormwater models to account for urban tree benefits, as well as associated resources and tools for estimating the hydrologic benefits of trees in the urban landscape.

Funded by the US Forest Service, the paper was developed with input from experts in stormwater engineering and urban forestry. This paper further augments a robust collection of resources the Center for Watershed Protection completed in 2017 on “Making Urban Trees Count”, which includes a comprehensive literature review and research-based tools for crediting trees in stormwater and water quality management programs.

If you have questions about this new resource please contact Karen Cappiella at