Hydroelectric Storage Project Near Joshua Tree Moves Forward

The Eagle Mountain mine, site of a proposed pumped hydro energy storage project | Photo: Chris Clarke | KCET   

A controversial project that would use an abandoned open-pit mine near Joshua Tree National Park for hydroelectric power storage has reached another milestone in the regulatory process. California's State Water Quality Control Board (SWQCB) has published a draft of a crucial environmental review document for the Eagle Mountain Pumped Storage Hydroelectric Project, which would provide about 1,300 megawatts of storage capacity for electrical power.

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The SWQCB document, a Draft Water Quality Certification, sets forth a number of conditions to which project developer Eagle Crest must agree to maintain certification. SWQC released the project's Draft Final Environmental Impact Report in January.

The purpose of the project is to help make energy derived from renewable sources available more reliably by using excess power from wind or solar to pump water from a lower reservoir in the former mine to one that's about 1,400 feet higher. When that stored energy is needed, water will be drained from the upper reservoir back into the lower through a set of turbines to generate power.

There are two main problems with the project. The first is evaporation: Eagle Mountain is in the heart of the California Desert, in an area with high temperatures and extremely low humidity. The reservoirs will hold about 35,000 acre-feet of water, of which SWQCB expects around 1,700 to evaporate annually. Another 1,400 acre-feet is projected to seep out of the reservoirs. Water to replace that lost to evaporation and seepage will be taken from the Chuckwalla Valley's groundwater, as will the original 35,000 acre-feet. The Chuckwalla Valley, as youo might guess, doesn't have all that much groundwater to spare.

The other problem is the creation of what will amount to large lakes in the desert. Open water can be a temporary boon for wildlife, of course, but providing a permanent source of standing water can seriously affect long-term wildlife populations. Of special concern is the possibility that the reservoirs will attract and sustain an increased population of ravens; ravens are a serious predator on baby desert tortoises, which are in trouble in the National Park that surrounds the Eagle Mountain site on three sides.

And as we've reported in the last few days, such a large project may not be necessary just yet.

The public has until April 10 to comment on the Draft Water Quality Certification.

For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.

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