Thursday, May 5, 2011

A new dam on the Yakima?

A great Yakima rainbow.  Better management will definitely help these guys.

There is a very interesting project being proposed for the Upper Yakima basin. This project includes putting in a new billion dollar dam, called the Wymer Dam, at Lluma Creek in the lower canyon, and pumping water from the upper river to the new dam to fill the resevoir, with the outcome of providing more water for irrigation in the lower valley.  This project is designed to provide more storage for irrigation in the Lower Yakima  

If you look at the yearly hydrograph for the Yakima, it is the opposite of how a natural river should behave.  In the spring the Yakima flows big with runoff, and has short bursts of snowmelt, but then stabilizes at a much higher then normal volume from June till September.  The water is then cut off at the beginning of September as lower valley irrigation needs are met by the Naches watershed.  This cutoff, known as the flip flop, drops the Yakima from 3,000 to 4,000 cfs to typically 1,000 cfs in a matter of a week. The large summer flows combined with the sharp flip flop create less than ideal conditions for trout, and although the yakima does support a healthy population of trout and an increasing amount of salmon and steelhead, a natural hydrograph would certainly help the watershed.

I am not sure that this dam is needed, but better control of the Yakima's flows would certainly be a benefit if this project is completed, and the potential to help fish in the Yakima is certainly there.  Here is a link to more info on the Wymer dam project from The Osprey: Link.  Below you can find the action list from the Osprey along with contact info.  Make sure that comments are submitted by the 19th of May.

All told the plan has the potential to greatly benefit fish populations in the Yakima basin, but it is critical that the measures which benefit fisheries be implemented fully and be given equal priority in federally appropriated funds. Comment today on the draft plan and tell the department of Ecology to:
  • Prioritize fish recovery and water conservation actions for immediate implementation even without congressional authorization for the full $4 billion in funding.
  • Increase storage capacity only after thorough environmental review and a determination that doing so will not have undue impacts on listed bull trout or other species.
  • Manage increased water storage such that it provides a more natural hydrograph and improved habitat conditions in the mainstem Yakima, and Naches Rivers.
  • Prioritize protection and restoration of the Teanaway River basin, where there is an imminent development threat but also considerable potential for salmon, steelhead, and bull trout recovery.
  • Include in the EIS an assessment of how the various alternatives will (or won’t) help fish populations survive and recover in the face of climate change
Comments are due by May 19th and can be sent to:

Attention: Candace McKinley, Environmental Program manager,
1917 Marsh Road
Yakima, WA 98901;
or by e-mail to


  1. thanks for posting this Joe!

  2. No problem. I'll be interested to hear what happens with this project. It's a huge project, but the benefit of having natural flows on the Yakima would greatly benefit it. The big push of irrigation water in the summer is like having a fire hose blasting nutrients downstream.


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