Some say the era of big dam building in California is past. In fact, the state currently has $2.7 billion dollars allocated by the passing of Proposition 1 to invest in further water storage projects, notably including the once-abandoned Temperance Flat Dam project on the San Joaquin River. The project would create the second tallest dam in California and could cost more than $2.6 billion. This is a remarkably high cost for a dam that will end up increasing the state’s water supply by only 1%. In fact, the California State Water Commission estimates the project will produce only 47 cents of benefits for every public dollar invested.
The benefits of this project are small, but the consequences are astronomical. It would drown more than 10 miles of the San Joaquin River Gorge, which flows through 6,000 acres of public lands enjoyed by more than 80,000 visitors annually. This very scenic area includes an extensive trail network used by hikers, mountain bikers, and equestrians, as well as two campgrounds, and an environmental education center. The gorge also provides critical habitat for 24 sensitive, threatened, and endangered wildlife species, including bald eagles and other protected creatures. Several sacred Native American sites throughout the canyon and the unique Millerton Cave system would be completely inundated with water. The Bureau of Reclamation itself has admitted that the project would have “long term, unavoidable, adverse impacts” on the scenery, recreation, riparian habitat, wetlands, and cultural resources of the San Joaquin River Gorge. The dam would also flood two existing hydropower plants.
A seven mile segment of the San Joaquin River Gorge was recommended for Wild and Scenic designation by the Bureau of Land Management in 2014 due to outstanding scenic, cultural, and recreational values. These river values far outweigh the minimal water storage the Temperance Flat Dam would offer. The San Joaquin is already one of the most heavily dammed rivers in California. More dams and diversions are not the solution to the water issues California faces CalWild is working hard to protect the future of the San Joaquin and prevent the Temperance Flat Dam.