Bull Run Watershed Study – SW Facility Inspections. Prince William County, Virginia.
Using methods developed by the Center for Watershed Protection, WRA conducted the inspection and evaluation of stormwater facilities in three (3) representative subwatersheds. The study targeted 20 existing wet and dry pond BMPs for inspection. Projects were selected for conceptual design, which included repairs to failing or substandard facilities, and water quality retrofits. Many of the proposed stormwater projects were combined with stream stabilization and riparian buffer enhancement projects. Five stormwater outfalls were identified suitable for a water quality retrofit. At each outfall, a bioretention facility was proposed, often in combination with riparian buffer plantings, stream restoration, and other water quality improvements. For each conceptual bioretention design, the drainage area was estimated, loadings calculated and potential nutrient reductions projected. In total, projects were identified to treat 15 acres of previously untreated impervious surface.