At a Glance
One of the oldest counties in the U.S. now has a roadmap to restoring a watershed degraded by development that preceded stormwater management regulations.
Much of Fairfax County was developed before stormwater regulations. In 2017, the State issued a TMDL requirement to reduce sediment within Accotink Creek. Long Branch, a tributary, was declared impaired, and its 3.7-square-mile subwatershed was assigned an annual waste load reduction of 2,433 tons. The County contracted Biohabitats to develop, implement, and monitor a holistic restoration approach focused on ecological uplift and TMDL compliance.
The initial stages of this multi-year effort focused on engagement, assessment, and monitoring. To involve stakeholders, Biohabitats developed a public input map to gather local knowledge from residents and users of the Long Branch Stream Valley Trail. Biohabitats completed a watershed assessment focusing on streams, outfalls, and stormwater retrofits. Assessments gathered data about existing conditions to prioritize restoration opportunities. A complimentary monitoring program evaluated the long-term health and resilience of the watershed. Pre-construction monitoring began in the fall of 2021.
Field assessment data, public input, and existing data resources were compiled into a project evaluation framework for identifying and prioritizing potential restoration projects. The framework scored retrofit opportunities within three categories: Ecological Benefits, Ancillary Benefits, and Feasibility. Stream restoration and retrofit priorities were identified for further field verification and integration into a phased implementation plan. Biohabitats will design and oversee the construction of seven miles of stream restoration and several stormwater retrofits.
Ecological Restoration, Water
Fairfax County Department of Public Works and Environmental Services
Fairfax, Virginia, United States
- Morton Thomas and Associates, Inc.
- Timmons Group