Retrofitting An Urban Reservoir For Effective Regional Stormwater Management

Built in 1934, College Lake serves 14,000 acres which is about 40% of Lynchburg's MS4 area. Over the years, the lake area and depth have reduced significantly due to sedimentation and spillway modifications. The storage volume in the lake today is less than 10% of its original volume 80 years ago. The Chesapeake Bay TMDL for nutrients and sediment requires significant reduction of pollutant loads over the next 13 years, which may cost Lynchburg over $100 million to meet the waste load allocations (WLAs) for urban stormwater. Due to its large drainage area, College Lake would well serve as a regional stormwater BMP with significantly improved performance when its storage capacity is restored by means such as dredging. However, the regulatory agencies are still yet to determine how much credit such retrofitting improvement practice will receive towards the compliance with Bay TMDL.