To bring the two dams into compliance with state dam safety and NRCS requirements, the Virginia Department of Conservation and Recreation (DCR) engaged Schnabel to evaluate up to three rehabilitation design alternatives based on our geotechnical exploration and analysis of the dams and auxiliary spillways.
The selected alternative for Lake Laura Dam consisted of a roller compacted concrete spillway over the embankment and closure of the original auxiliary spillway. The new spillway increased flood storage and reduced the frequency of activation of the auxiliary spillway.
The replacement spillway for Bird Haven Lake Dam was a reinforced concrete spillway with an ogee weir. The improved hydraulic efficiency reduced excavation-related costs and eliminated potential easement issues by fitting within the footprint of the existing spillway. Schnabel exceeded NRCS stability and integrity criteria by modifying the exit channel and adding turf reinforcement matting.
- Geotechnical Investigation
- Hydrology and Hydraulics
- Conservation Planning