Department of Conservation and Recreation
Conserve. Protect. Enjoy.
Department of Conservation and Recreation
The Cobbs Creek Reservoir Dam is a major infrastructure project designed to meet the rising water needs of Henrico County and bolster the region’s drought resilience for the next 50 years. The 1,117-acre reservoir will hold approximately 15 billion gallons of water at normal pool.
Construction on the dam commenced in 2017 and the initial pump filling of the reservoir began in June 2024. The project was declared substantially complete earlier this month and is expected to reach full operational capacity in 2025.
Cobbs Creek Reservoir Dam is an extraordinary project in the Commonwealth of Virginia. It is a pump storage facility, meaning that nearly all the water stored in the reservoir is pumped from the James River during higher river flows. Water is then released as needed back into the James River to flow on to Henrico County where it is then used by Henrico County Public Utilities. While the dam is located in Cumberland County it was commissioned and is owned and operated by Henrico County. Cobbs Creek Reservoir Dam is one of the largest dams constructed in the Commonwealth in recent decades.
The project was already well underway when I started my current position as Regional Dam Safety Engineer in September 2020. By that time a Construction Permit Application had been reviewed and approved by DCR Dam Safety and the embankment construction was approximately half complete. Obviously, I had a lot to catch up on. My role during construction was to monitor progress through regular site visits and communication with the design engineers, owner representatives and the general construction contractor. Once the project was complete, I reviewed the as-built drawings and the Certification by the Engineer of Record allowing the filling of the reservoir to begin.
As Regional Dam Safety Engineer my primary concern and goal is that regulated dams in Virginia meet the requirements laid out in the Dam Safety Act and the Virginia Impounding Structure Regulations. Cobbs Creek Reservoir Dam is not unique in this regard. While this dam is classified as High Hazard Potential dam, there are many such dams in Virginia. The Hazard Potential is determined by its potential impacts and is not indicative of the dam’s condition. This dam’s potential impacts spread across over a dozen localities and entities; therefore, it is imperative that the Emergency Action Plan remains up to date and a Table-Top Exercise is held regularly along with annual emergency drills.
What this means is that the dam’s potential impacts are primary roads, critical infrastructure, habitable buildings, etc. A High Hazard Potential dam requires more frequent Professional Engineer Inspections and requires regularly updating and exercising the Emergency Action Plan. Again, this is not indicative of the dam's condition and does not mean that it is inherently dangerous to the public.
The long-term maintenance plans for this dam are the same as for all dams; to maintain adherence to the Virginia Impounding Structure Regulations which includes maintaining an active Operation & Maintenance Certificate. The Operation & Maintenance Certificate plan is developed by the owner’s engineer, reviewed and approved by DCR Dam Safety, and includes the required frequency of maintenance and inspection of the dam’s various components.
DCR’s Dam Safety Program regulates over 2,500 dams in Virginia. You can learn more about dams by visiting DCR’s Dam Safety Education portal and view dams in your area by accessing our Open Data Hub or the Virginia Flood Risk Information System (VFRIS).
Categories
Dam Safety | Dam Safety and Floodplains
Tags
dams | flood control
