:: GIC Projects :: Protecting and Restoring Urban Tree Canopy for Stormwater Management

::What Is This Project?

The Green Infrastructure Center has joined with six states -- VA, NC, SC, GA, FL, and AL -- from across the Southern Region to study how urban trees mitigate stormwater runoff. Funded by the US Forest Service’s Southern Region, the GIC and the states have been awarded funds to provide cities with technical assistance to achieve this goal. The project is showing how southern cities can utilize their urban forests as a vital tool for managing and reducing stormwater runoff.

Excessive stormwater runoff accounts for more than half of the pollution in America’s surface waters and causes increased flooding and property damages as well as public safety hazards. National studies indicate that land conserved for stormwater retention and flood prevention “show an eight-to-one dollar savings ratio versus man-made flood-control structures” (McDonald 2015). We need to find ways for cities to better integrate trees into their stormwater management programs.

Valuing the benefits of the urban forest helps us to better understand the contribution of trees to the ‘ecosystem services’ that trees provide such as cleaner water, air, shade, and stormwater uptake and aesthetic values. An important feature of ecosystem services is that they often provide cost savings over the construction and use of traditional grey infrastructure. One urban tree can intercept thousands of gallons of water annually. But while the benefits of trees are well known, most cities do not include trees as a component of their stormwater management strategies.


Eleven representative cities and one county were selected to participate. They include localities of large, medium and small densities and are found in the mountains, the piedmont and the coastal plain. Participating localities are innovators for effective, greener stormwater management. Localities selected to participate by the states include:

  • VA: Norfolk, Lynchburg, Harrisonburg

  • NC: Apex, Wilmington

  • SC: Charleston

  • GA: Norcross, Alpharetta

  • FL: Orange County, Jacksonville, Miami Beach

  • AL: Auburn

Trees and the Water Cycle



  • Tool to evaluate urban runoff (for adding or losing tree canopy).

  • Tool to evaluate urban codes, policies and practices to learn which make the city more impervious or pervious.

  • Recommendations for how to improve city codes and practices to reduce runoff and replant or retain canopy.

  • Maps of the urban forest and planting opportunities.

  • A case booklet for each pilot locality detailing the project, methodology, lessons learned and best practices for other cities who wish to do this work.

Read the completed case booklets here!

The final report will include a synthesis of all projects.

Tools to calculate stormwater uptake and to evaluate city policies and codes will be made available to use at the end of the project.

Comments or questions? Contact GIC at 434-244-0322 or mccormick@gicinc.org

Focus Group Workshop

Group Workshop


Great egret.

People shop longer and pay about 20% more in tree-lined commercial streets.


Econlockhatchee River in Orange County.


Bearded Heron, Apex NC.