List of dam removals in California

This is a list of dams in California that have been removed as physical impediments to free-flowing rivers or streams.

Owned by California American Water, the San Clemente Dam on the Carmel River was deemed unsafe in 1992 by the Department of Water Resources. It was no longer serving its use by supplying water to the Monterey Peninsula and blocked steelhead from spawning upstream. It was demolished in 2015.^[1] Similarly, the Old Carmel River Dam was demolished in 2016.

The Pacific Gas and Electric Company has operated two hydroelectric dams on the Eel River as part of the Potter Valley Project: Scott Dam and Cape Horn Dam. In 2023 the company applied to demolish the dams amid growing issues with maintenance, environmental compliance, and seismic liability. The project would drain Lake Pillsbury and Lake Van Arsdale, making the Eel the longest free-flowing river in California and restoring hundreds of miles of habitat for endangered fish.^[2]

After more than 20 years of advocacy from the Un-Dam the Klamath movement, the four dams on the Lower Klamath River were removed in 2023 and 2024. Three of these were in California: Iron Gate Dam, Copco Number 1 Dam, and Copco Number 2 Dam. The removals are expected to improve salmon passage. As of 2025 this is considered the largest dam removal project in history.^[3][4]

Completed in 1923, O'Shaughnessy Dam is a 430-foot-high (131 m) concrete arch-gravity dam on the Tuolumne River, a tributary of the San Joaquin River, flooding Hetch Hetchy Valley within Yosemite National Park.^[5] Considered the first great environmental controversy in the United States when constructed, O'Shaughnessy Dam continues to be controversial. Environmental groups such as the Sierra Club lobby for breaching the dam and restoring the valley, while others argue that leaving the dam in place would be the better economic and environmental decision.^[6]

The Trabuco District Dam Removal Project is an initiative of the Cleveland National Forest to remove over 80 dams on four streams: San Juan Creek and its tributaries Holy Jim Creek and Trabuco Creek, as well as Silverado Creek, a tributary of the Santa Ana River. The "fish check dams" were originally built to create pools for a stocked rainbow trout fishery and to store water for conservation and fire suppression. The removals are intended to improve passage of fish and other aquatic species.^[7][8]

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