Stormwater runoff can contain two ingredients that are harmful to shellfish: chemical pollutants, which can poison shellfish, and excess nutrients, which can promote the growth of algae blooms and lead to oxygen depletion in coastal waters. To protect shell fish habitat near Wilmington, NC, the City of Wilmington and the North Carolina Coastal Federation partnered on a watershed restoration initiative to systematically reduce the impact of stormwater runoff.
To support the partnership, WithersRavenel developed a Web-based GIS database of stormwater retrofit sites. This atlas provides a portal for City staff to catalog potential and completed retrofit sites and quickly analyze the water quality benefits of each project; it also includes a publicly accessible Web site component where citizens can document their participation in the watershed restoration efforts by adding their efforts to the map.
The restoration plan deliverables also included standard design details, construction drawings for five retrofit sites, public education materials, meetings, and workshops. The plan was adopted by City leaders and approved by the North Carolina Department of Environment and Natural Resources Division of Water Quality in lieu of a Total Maximum Daily Load (TMDL) allocation.