With the vast majority of our dams approaching the end of their intended design lives, safety measures to preserve their structural integrity must be put in place.
Dams are mighty to behold and immensely impressive in generating power. The Hoover Dam in Colorado—the largest dam in the U.S.—supplies 1.5 million residents alone in three neighboring states with cheaper electricity, and it is only one of the approximately 91,000 dams in this country.
However, many of these dams are from a more infrastructurally ambitious era, with their average ages now beyond 56 years. By 2025, 70% of our dams will be more than 50 years old, representing a pressing safety issue as they near the end of their intended design lives.
These safety issues arise in part from dams’ physical deficiencies. These structures hold back water, which tends to erode their integrity over time, the deterioration of which is worsened by chemical runoffs that accumulate in waterways. Furthermore, older dams were built with outdated engineering techniques and materials, which do not cope as well with natural disasters.
On top of that, 17% of dams in the U.S. had high-hazard potential in 2017, meaning their hypothetical failure would most likely cause loss of life and extensive property damage, according to the American Society of Civil Engineers. Thirty-four lives have been lost to dam accidents in the past 40 years despite a significant rise in governmental safety precautions in the 1970s.
This may be, in part, the result of dams’ lack of centralized oversight. Only 4% of all dams in America are owned by the federal government, with approximately 60% owned by private entities that are solely regulated by state authorities with differing safety standards and varying funding levels.
While California, with an annual budget of $12.8 million, managed to inspect every high-hazard dam in 2014, Georgia had $0.67 million and inspected only 4.6% of its own, thus creating regional “hotspots” of dam failures.
Sources
“Dams,” 2017 Infrastructure Report Card. American Society of Civil Engineers, 2017.
Lieb, David, et al. “AP: At least 1,680 dams across the US pose potential risk.” AP News, 11 Nov. 2019.
Panda, Abha. "Case Study: America’s Dam Disaster." The Center for Social Solutions, University of Michigan, 25 June 2020. https://lsa.umich.edu/social-solutions/news-events/news/insights-and-solutions/case-studies/case-study--america-s-dam-disaster.html.
Pupovac, Jessica. “Aging and Underfunded: America’s Dam Safety Problem, in 4 Charts.” NPR, 11 Oct. 2015. https://www.npr.org/2015/10/11/447181629/aging-and-underfunded-americas-dam-safety-problem-in-4-charts.