American Whitewater Opposes Temperance Flat Dam (CA)

Posted: 10/30/2014
By: Megan Hooker

American Whitewater submitted comments this week to the Bureau of Reclamation in opposition of the proposed Temperance Flat Dam slated for the San Joaquin River in California. The proposed dam would be located at River Mile 274, just upstream of Friant Dam and Millertown Reservoir.

If built, the Temperance Flat Dam would have significant impacts to the San Joaquin River Gorge, including drowning several Class III-V whitewater runs, including Patterson Bend. This is a beautiful stretch of river–one that the Bureau of Land Management recognized as suitable for inclusion in the National Wild and Scenic Rivers System in 2012 for its cultral and scenic values.

In addition to drowning Class III-V whitewater runs, the proposed reservoir would flood:

  • an extensive trail system,
  • two public campgrounds,
  • an environmental education center,
  • a nature and cultural history museum,
  • sites that are significant to area tribes,
  • prime habitat for 24 sensitive, threatened, and endangered wildlife species, and
  • the unique Millerton Cave System.


Proponents claim that the project will benefit salmon, however these improvements depend on operation scenarios, and at best increase salmon by just 2.8%. Some operation scenarios actually reduce salmon by 0.6% to 13.1%, which is a loss on the investment that Californians have made in restoring salmon over the last 20 years.

Temperance Flat Dam is not the solution to California's extreme drought. Eight large dams and reservoirs already capture and divert most of the San Joaquin's flow, and the river is already over allocated. If built, the Temperance Flat Reservoir would only increase the state's water supply by 0.2% and store a modest amount of water in only one of every three years. This last figure is based on historical hydrological records, meaning less water will be stored if the drought continues. This little amount of water would come with a big price tag–the project would cost $2.6 billion to build and about $121 million to operate each year. If the Water Bond passes this fall, it will fund projects for water storage, which could include Temperance Flat. The project would also reduce electricity production because it would flood two powerhouses that are part of PG&E's Kerckhoff Hydroelectric Project upstream.

You can view our comments to the right. For more information, you can download this fact sheet from Friends of the River, and view the Draft Environmental Impact Statement and Appendices. Stay tuned to American Whitewater for updates.

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