The Cost of Rehabilitating Our Nation’s Dams

In 2022, the ASDSO Board of Directors established a task force to review and update the methodology and processes that were developed several years earlier by ASDSO to estimate the costs to rehabilitate non-federal dams in the United States (U.S.). This was a one-year project financed by ASDSO. The updated methodology and processes used readily available data to estimate the number of dams in need of rehabilitation based on dam height, age, and Condition Assessment rating. Data from more than 500 dam rehabilitation projects nationwide, ranging from $10,000 to more than $500 million, was used in determining the total amount of funding needed for dam rehabilitation at a national level. The purpose of this report is to inform national and state policy decisions and provide the public and the media with a high-level understanding of the national dam rehabilitation need in terms of estimated costs. The findings and methodologies are not meant to be used to estimate a specific dam rehabilitation cost. 

Based on the 2026 study detailed in this report, ASDSO estimates the cost to rehabilitate the nation’s non-federal dams at $209.6 billion with $48 billion of that amount needed just for the most critical dams (high-hazard potential dams). Costs will continue to rise as maintenance, repair, and rehabilitation work is deferred. Cost updates will be calculated on a biennial basis and provided as an update to this report.