Dams in Virginia: How Many Are Deficient?

Location of Virginia's 2,919 known dams.

Location of Virginia’s 2,919 known dams. Map source: U.S. Army Corps of Engineers, National Inventory of Dams

Speaking of deficient bridges (see previous post), how about deficient dams? The potentially disastrous erosion around the Oroville dam in California, which prompted the evacuation of 188,000 people living down river earlier this week, prompted two correspondents to raise the issue with Bacon’s Rebellion.

John Butcher passed along an article noting that the Oroville dam is symptomatic of rampant neglect and deferred maintenance across the country. Writes the Peak Prosperity website:

The points of failure in Oroville’s infrastructure were identified many years ago, and the cost of making the needed repairs was quite small — around $6 million. But for short-sighted reasons, the repairs were not funded; and now the bill to fix the resultant damage will likely be on the order of magnitude of over $200 million. Which does not factor in the environmental carnage being caused by flooding downstream ecosystems with high-sediment water or the costs involved with evacuating the 200,000 residents living nearby the dam. …

Oroville is one of the best-managed and maintained dams in the country. If it still suffered from too much deferred maintenance, imagine how vulnerable the country’s thousands and thousands of smaller dams are. Trillions of dollars are needed to bring our national dams up to satisfactory status. How much else is needed for the country’s roads, rail systems, waterworks, power grids, etc?

The Smith Mountain Lake dam, owned and operated by Appalachian Power Co., rises 235 feet from its floor.

So, what do we know about the dams in Virginia? Steve Nash sent me a link to the U.S. Army Corps of Engineers National Inventory of Dams. That database identifies 2,919 structures in Virginia, mostly small (less than 50 feet high), mostly earthen, and mostly privately owned. Eighty-four dams date back to the 19th century, but a large majority were completed in the 1950s, 1960s, and 1970s.

Here’s the worrisome part: the Corps classified 468 dams as having “high” hazard potential and another 551 as having “significant” hazard potential, with another 612 undetermined. The classification of “high” hazard potential does not mean that there is a high likelihood of failure; rather, it means that failure , if it occurred, would probably cause “loss of life or serious economic damage.”

However, 2,035 of Virginia’s dams, like California’s Oroville, are made of earth, which is especially vulnerable to erosion.

According to the Virginia Department of Conservation and Recreation, which regulates dam safety in Virginia, dams must be inspected periodically by licensed professionals. If a dam has a deficiency but does not pose imminent danger, the state may issue a Conditional Operation and Maintenance Certificate, during which time the owner is to correct the deficiency. It’s not clear what happens if the owner fails to correct the deficiency. Small loans and grants are available to help cover the cost.

Presumably, within the bowels of the Virginia bureaucracy, there is documentation that would allow the public to determine which high-hazard dams, if any, are in deficient condition. Where are they are located and who owns them? If I lived downstream from one, I sure would like to know.

If any Bacon’s Rebellion reader would be willing to root around the state archives to unearth this information, please contact me at jabacon[at]baconsrebellion.com.