The Conversation - Climate change is increasing stress on thousands of aging dams across the US
Water flows around the Rapidan Dam near Mankato, Minn., on June 24, 2024, after heavy rains in the Upper Midwest. AP Photo/Mark Vancleave
This article from The Conversation highlights how the heavy rainfall in late June 2024 caused significant flooding in the Upper Midwest, putting the aging Rapidan Dam in southern Minnesota at risk of failure. This event follows similar dam-related issues in Vermont the previous year. Hiba Baroud, an expert in civil and environmental engineering at Vanderbilt University, emphasizes how flooding can erode dams, leading to potential breaches and uncontrolled water releases.
The risk to a dam depends on factors like age, maintenance, and spillway capacity. Overtopping, a major cause of dam failures, can be particularly dangerous for older structures. The U.S. has over 91,000 dams, with an average age of 57 years, and more than 8,000 exceeding 90 years. The American Society of Civil Engineers' latest report card gave U.S. dams a "D" grade, noting that many high-hazard dams lack emergency action plans.
Strengthening older dams without full replacement is possible through regular maintenance and upgrades. However, the cost of rehabilitating all nonfederal dams is estimated at $157.7 billion, with $34.1 billion needed for high-hazard dams alone. The 2021 Infrastructure Investment and Jobs Act allocated around $3 billion for dam safety projects.
Climate change exacerbates the stress on dams by increasing the frequency and severity of natural hazards. Historical design standards are outdated, making it crucial to incorporate future climate projections in new designs and upgrades. The recent spate of disasters underscores the need for proactive disaster planning and emergency action plans.
As the U.S. navigates the complexities of dam safety in changing climatic conditions, ongoing initiatives like the Canada1Water project (C1W) provide crucial research and data for informed resource management strategies.
Aging dams are vital for drinking water, irrigation, energy, and flood protection, and their failure can have widespread economic impacts. Understanding the direct and indirect costs of such failures is essential for developing robust disaster preparedness strategies.