By Lynn Boulton, Range of Light Group Chair
The fate of Fish Slough and its 14 imperiled species are now in the hands of a small water district. Fish Slough is a national treasure in the Eastern Sierra north of Bishop, Calif., that is drying up. The water table in Fish Slough has been in decline for the past 20 years. Marvin’s Marsh in the northwest side of the slough has already dried up and a key spring called the Northeast Spring will have zero discharge this summer. You would think that the new California groundwater management law, SGMA, would save it, but it won’t. It is up to the ranchers, farmers, and residents in the Tri-Valley water district to save Fish Slough.
Fish Slough is on a flat valley floor between the Volcanic Tablelands and a low mountain ridge. In the spring, this slough turns green and is alive with birds, bees, butterflies, and wildlife. In winter it is monochromatic brown interspersed with rust colored marsh marigolds. It is well known as the home of the endangered Owens pupfish that live in the springs and the slough. One of the last remaining natural habitats. This species almost perished in 1969 when fish biologist, Phil Pister discovered the only spring with the pupfish was drying up. Phil scooped them up in a bucket and saved them. Since then, the California Department of Fish and Wildlife biologists have been translocating the pupfish to other locations to help this species survive.
There are two key reports (here and here) that show that the water flowing through Fish Slough comes from the Volcanic Tablelands and the Tri-Valley. The groundwater flows from the Benton Range and White Mountains in the north, south towards Bishop. When it reaches the lower part of the Tri-Valley, it is shunted west around a block of bedrock to Fish Slough. Very little flows directly south. However, groundwater pumping significantly diminishes the groundwater flow before it reaches Fish Slough. Fish Slough is in the middle between Los Angeles Water and Power’s (LADWP) water diversions to Los Angeles and the ranchers, farmers, and residents of the Tri-Valley’s water needs. If Tri-Valley residents use all of the groundwater for themselves in order to keep it out of the hands of LADWP, then little or none would flow through Fish Slough and it would dry up. Tri-Valley’s water users have to leave some for Fish Slough even if it feeds the aquifer that LADWP can tap. That’s a big ask.
Show your concern for Fish Slough by writing the California Department of Water Resources sgmps@water.ca.gov and ask them to ensure the Tri-Valley groundwater is managed under a Groundwater Sustainability Plan and ask them to fund projects that address the data gaps needed to manage the groundwater.
Read more about Fish Slough in the New York Times.
Donate to help the Sierra Club protect Fish Slough and other imperiled natural treasures.
