Decommissioning a 90-Year-Old Dam on Blackwater Creek
Emily Burgess
AECOM
Germantown, MD
In November 2023, AECOM began supporting the City of Lynchburg in conducting construction observation and inspection services for the full dam decommissioning of College Lake Dam. College Lake Dam is a 30-foot-tall earthen embankment and roadway that is over 90 years old and has nearly failed multiple times due to increased precipitation and runoff in the watershed. Due to its inadequate spillway capacity to pass the 90% probable maximum flood (PMF), it is listed as a high-hazard dam and is operating on a conditional dam safety permit. The project construction included 24-hour monitoring operations during installation and operation of a unique siphon dewatering system and at critical times during the dam breaching phase of construction. This presentation will detail some of the challenges and insights gained during construction, including tips on performing lake dewatering, management of loose, contaminated sediment, stream, and wetland restoration, in-stream structure construction, and working in the wet to restore connectivity and provide fish passage along Blackwater Creek, a third order stream through an urban watershed.
About Emily Burgess
Emily Burgess is a Water Resources Engineer with 6 years of experience in engineering consulting. She has worked on designs in stream restoration, stormwater management, and green infrastructure and has a long list of outdoor hobbies, including birding, mountain biking, and backpacking!