The cost of rehabilitating federal and non-federal dams in the U.S. has risen to more than $70 billion, according to a 2019 update of a report from the Association of State Dam Safety Officials (ASDSO). The cost to rehabilitate those dams where the risk is highest exceeds $23 billion.
Using the information in the 2018 National Inventory of Dams (NID), ASDSO estimated the cost of rehabilitating the country’s more than 90,000 dams. In 2003, ASDSO published its original cost estimates in a report entitled, The Cost of Rehabilitating Our Nation’s Dams: A Methodology, Estimate and Proposed Funding Mechanisms. The report was updated in 2009, 2012, 2016 and 2019.
Current figures place the total cost estimated for non-federal dams at $65.89 billion, up from the last estimate of $60.70 billion. Non-federal, high-hazard-potential dams are estimated at $20.42 billion, up from $18.71 billion. High-hazard-potential dams are those where failure or mis-operation will likely lead to loss of human life.
Since the 2012 update, the cost of federally owned dams has also been considered. In the current update, it is estimated that $4.78 billion is needed to rehabilitate all federally owned dams, with $3.35 billion of this attributed to federally owned high-hazard-potential dams.
Occasional upgrade or rehabilitation is necessary due to deterioration, changing technical standards, improved techniques, better understanding of the area's precipitation conditions, and changes in downstream populations or land use, ASDSO says.
ASDSO says an important step toward reducing cost is creating and supporting funding assistance by the federal government and states. The majority of dams in the U.S. are privately owned, leaving owners solely responsible for financing dam upkeep and upgrades.
On the state level, ASDSO encourages loan and grant programs for rehabilitation funding. On the national level, ASDSO encourages full funding for the High Hazard Potential Dam Rehab Grant Program and for federal agencies to continue supporting dam safety initiatives.