Our Aging Infrastructure: Danger Pent Up Behind Aging Dams
Of the nation’s 85,000 dams, more than 4,400 are considered susceptible to failure, according to the Association of State Dam Safety Officials. But repairing all those dams would cost billions of dollars, and it is far from clear who would provide all the money in a recessionary era.
Photo: Michal Czerwonka for The New York Times
NOT INACTIVE Engineers now know that the Lake Isabella Dam [upstream from Bakersfield, CA] lies on an active fault line. Below, a survey monument used to measure ground movement.
Nationwide, the potential repair costs are staggering. A 2009 report by the state dam safety officials’ group put the cost of fixing the most critical dams — where failure could cause loss of life — at $16 billion over 12 years, with the total cost of rehabilitating all dams at $51 billion. But those figures do not include Lake Isabella and other dams among the approximately 3,000 that are owned by the federal government. The corps, for example, says that more than 300 of the roughly 700 dams it is responsible for need safety-related repairs, and estimates the total fix-up bill at about $20 billion.
The corps has already spent about $24 million just to determine the scope of the problems at Lake Isabella, and with the New Orleans levee failures during Hurricane Katrina a lingering memory, Congress has appropriated money for other federal dam repair projects as well.
But about two-thirds of all dams are private, and financially struggling state and local governments own most of the remainder. It is difficult to predict how needed repairs to these dams will be financed; legislation to provide federal money to help has languished in Congress.