| Repairs


determining specific dam rehabilitation costs, the ASDSO said. The report says that to reduce the risk to the public, investments are necessary at the federal, state, and local levels to rehabilitate tens of thousands of dams that require upgrades to meet current design and safety standards. However, private dam owners or those without a revenue stream may find it challenging to finance costly rehabilitation projects. Additionally, bolstering state dam safety regulatory programs responsible for overseeing the safety of approximately 70 percent of the nation’s dams, including many posing high risks to public safety, requires increased statutory authorities and investments. Unfortunately, many state dam safety programs lack sufficient funding and state statutory authorities, which are essential to reduce dam safety risks for public safety. Similarly, investments at the federal level are necessary to continue repairing and rehabilitating high-hazard potential dams owned and regulated by federal agencies. The failure of even one of these dams could have severe adverse impacts on significant populations and commerce centers. As scientific knowledge, dam safety standards, and best practices advance, the nation’s dams are now subject to stricter safety criteria compared to when they were initially constructed. With an average age of 61 years, many dams may not be able to withstand loadings from extreme storms and earthquakes, and by 2025, seven out of 10 dams in the US will be over 50 years old. Further, development in downstream areas of previously low-hazard potential dams has caused these dams to be deemed high-hazard potential, necessitating their rehabilitation to meet higher, more stringent safety standards that protect life and property. While these dams may have been built to the best engineering and construction standards of their time, many of those standards are now less stringent than current ones, making these dams a risk to public safety. To address these risks, greater attention and investment are necessary to reduce public safety and economic asset risks.


Recent events, such as the Oroville Dam Spillways Incident in California (2017), and the failures of Spencer Dam in Nebraska (2019) and Edenville Dam in Michigan (2020), have highlighted the need for comprehensive engineering reviews and more frequent, detailed inspections of dams across the country. Such efforts have uncovered and will continue to identify more dam safety issues. As a better understanding of the level of risk posed by these dams is gained, it is expected that the number of deficient dams requiring rehabilitation will increase.


Updated study In 2001, a task group was formed by the ASDSO


Board of Directors to prepare a report on the cost of rehabilitating the nation’s dams. The group developed a methodology for estimating the funding needed to rehabilitate approximately 65,000 non-federal dams based on a national inventory of dams and available rehabilitation cost data. This methodology was updated in 2009 to account for changes in the inventory of over 83,600 non-federal dams, inflation, engineering assessments, and deferred maintenance. Since then, ASDSO has routinely updated cost estimates based on dam statistics in the US Army Corps of Engineers’ National Inventory of Dams.


In 2022, the ASDSO Board of Directors requested a full update to the previous report, and a new task force was convened to review the methodologies and associated rehabilitation cost estimates utilized in previous reports, collect dam rehabilitation cost data, and update methodologies as needed. ASDSO members were asked to provide actual dam rehabilitation costs for non-federal dam repairs over the past 10 years and estimated costs for known upcoming projects, resulting in the collection of cost data for over 500 projects from across the nation. Outlying data was identified and not included if it overly skewed the cost estimates. The task group concluded that a national cost estimate to repair the nation’s non-federal dams, based on available data, is $157.5 billion. Of this figure, approximately $34.1 billion is needed for non-federal high-hazard potential dams where loss of life is probable should the dams fail or be mis-operated.


Positive developments The report points out that in recent years, there have


been positive developments in federal and state funding programs to support dam rehabilitation projects. In 2016, the High-Hazard Potential Dams Rehabilitation (HHPD Rehab) Grant Program was established under the National Dam Safety Program administered by FEMA. At its highest funding level, the program was authorized for $60 million annually. More recently, the Bipartisan Infrastructure Law (also known as the Infrastructure Investment and Jobs Act) was passed in 2021, which allocated an additional $585 million to the HHPD Rehab Grant Program. This funding can be used for dam rehabilitations and removals until expended. The Natural Resources Conservation Service (NRCS) of the Department of Agriculture also offers grants through its Watershed Rehabilitation Program for the rehabilitation of NRCS- built dams owned by local sponsors. Furthermore, the U.S. Army Corps of Engineers has established the Water Infrastructure Financing Program, which provides low-interest loans to dam owners for rehabilitation projects. ASDSO’s task force member Sharon Tapia however said that to ensure the safety of the nation’s dam, high funding levels must be maintained to address the thousands of dams needing rehabilitation. “We cannot return to previous funding levels, typically less than one percent annually of the investment made in the Bipartisan Infrastructure Act.”


References


The Cost of Rehabilitating Dams in the U.S.: A Methodology and Estimate:


https://www.damsafety.org/ RehabEstimate


Task Force


Task Force members for the report were: Sharon Tapia, California Division of Safety of Dams Shawn Jones, California Division of Safety of Dams Tony Nokovich, American Water Company John Ritchey, French & Parrello Associates Raul Silva, Massachusetts Department of Conservation and Recreation Eric Ditchey, Eric J. Ditchey PE LLC Boris Slogar, Muskingum Watershed Conservancy District Lori Spragens, ASDSO Mark Ogden, ASDSO


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