Controversial plan to dismantle Hetch Hetchy Dam sparks environmental debate

A proposal has emerged to dismantle the 300-foot dam in Hetch Hetchy Valley, a site neighbouring Yosemite National Park. The plan, put forward by environmental advocate Larry Pearson, aims to restore the valley’s natural landscape and open it to the public. If approved, the move would require San Francisco to relocate its water supply, as the dam has served the city since 1934. Hetch Hetchy Valley was flooded nearly a century ago when San Francisco built the O’Shaughnessy Dam. The project turned the scenic valley—known for its waterfalls, cliffs, and hiking trails—into a reservoir. The dam provides the city with affordable water and hydroelectric power, but it also submerged a landscape often compared to Yosemite in beauty.

Pearson argues that removing the dam would allow the valley to return to its natural state. He points to recent dam removals across the US, many of which restored salmon spawning grounds and reopened public access. However, San Francisco would need to find a new water storage solution before any demolition could begin. The debate comes as Yosemite Valley faces its own access challenges. A reservation system introduced to manage crowds has left many visitors frustrated, yet demand remains high. Restoring Hetch Hetchy could ease pressure on Yosemite by offering an alternative destination. Pearson insists the city should cover removal costs, as it has long benefited from the dam’s resources.

The proposal highlights a clash between environmental restoration and urban needs. If the dam is removed, San Francisco must secure another water source. Meanwhile, the valley could once again become a public space, mirroring Yosemite’s natural appeal.