American Rivers: Hawaii Dam Statistics and Experts Available as Extreme Weather Threatens River Infrastructure
Contact: Hawk Hammer, National Communications and Media Director, Hhammer@americanrivers.org
Catastrophic Storms Prompt Evacuations Downstream of High Hazard Dam in Waialua in Hawaii
As severe storms bring life-threatening flooding across Hawaii, emergency officials have begun evacuations below the Wahiawa Dam in Waialua. The Wahiawa Dam is categorized as high-hazard, meaning if it fails, it could cause significant property damage or loss of life.
“We are hoping above all for the safety and well-being of all in harm’s way. This is a terrifying situation that we are increasingly seeing nationwide as extreme weather pressures our aging and outdated water infrastructure,” said Brian Graber, a dam removal expert with American Rivers. “The number of U.S. dam failures and emergency incidents have dramatically increased over the last 30 years. Fortunately, the Wahiawa Dam had an Emergency Action Plan and officials were right to implement it to protect people downstream. The catastrophic failure of the Ka Loko Dam in 2006 on the island of Kaua’i is still on the minds of many. Dams built decades or even centuries ago were usually not designed to handle the intensity of the storms we’ve seen in recent years.”
“Infrastructure that impedes the powerful flow of rivers will always present risk,” said Graber. “It’s good policy to pursue a balanced approach of investing in the upkeep and safety of dams that serve a critical purpose and removing those that don’t. Dedicated investment in state and federal dam safety and dam removal programs is desperately needed.”
Hawaii Dam Statistics:
- According to the Aquatic Barrier Inventory and Prioritization database there are 1,037 dams across the state.
- According to the National Inventory of Dams, 116 dams, including the Wahiawa Dam, are categorized as High-Hazard Potential, meaning that dam failure could cause loss of life or significant property damage.
- Since 1912, there have been 23 dams removed in Hawaii with the latest being the Kaupakalua Reservoir Dam in Maui in 2022. Kaupakalua was removed after it forced downstream evacuations in March, 2021.
- The Ka Loko Dam failed in 2006 on the island of Kauaʻi, killing 7 people downstream.
National Statistics
- Nationwide there are roughly, 16,700 high hazard dams.
- The average age of dams nationwide is 64 years old.
- There are estimated to be more than 500,000 dams impeding natural river flow across the nation, many of them outdated, unsafe, or obsolete.
- More than 2,350 dams have been removed across the country since 1912.
- 100 dams were removed in the United States in 2025.
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About American Rivers
American Rivers is championing a national effort to protect and restore all rivers, from remote mountain streams to urban waterways. Healthy rivers provide people and nature with clean, abundant water and natural habitat. For 50 years, American Rivers staff, supporters, and partners have shared a common belief: Life Depends on Rivers. For more information, please visit AmericanRivers.org.
