L.A.’s Water Diversions Threaten Critical Habitat Far to the North

The nonprofit Mono Lake Committee recently filed a request with the State Water Resources Control Board that asks for the suspension of Los Angeles Department of Water and Power’s (LADWP) water diversions from Mono Lake, located about 330 miles away from Los Angeles, east of the Sierra Nevada mountain range.

According to an article by Louis Sahagún for the Los Angeles Times, the Mono Lake Committee hopes to alleviate a threat to natural habitat at the lake.

In its request, the nonprofit Mono Lake Committee argues that the combination of drought and diversions from streams that feed the lake are exposing the lake bottom near islands that host one of the world’s largest nesting gull populations. Unless this is addressed, they say coyotes will be able to access the islands and feast on the eggs of 50,000 California gulls.

Sahagún also provides a history of the city’s diversions from the lake:

Los Angeles […] has been importing water from this eerie, hyper-saline lake since World War II. Last year, the DWP rejected a committee request that it voluntarily cease its diversions of 4,500 acre-feet of Mono Lake water each year. One acre-foot of water is enough to fill an Olympic-size swimming pool halfway.

The water diverted from Mono Lake amounts to roughly 1% of the water consumed by Los Angeles residents in a year. While the city got good news about a recovered source of drinking water at the end of 2022 thanks to a superfund project in the San Fernando Valley groundwater basin, the city still relies on imported water from various environmentally troubled sources, including Mono Lake, the Colorado River, and the Owens Valley. The Owens Valley provides a regional example (located about 70 miles south of Mono Lake) of the environmental risks of L.A.s water supply diversions. The Owens Valley is completely dry, kicks up dust that is a public health risk to local residents, including the indigenous Bishop, Big Pine and Lone Pine tribes of Owens Valley Paiute Shoshone Indians.

Meanwhile the number of gull nests around Mono Lake declines. “The largest number of gull nests ever recorded at Mono Lake was about 32,000 in the early 1990s. In 2019, 11,075 nests were counted, the lowest number recorded over the 34-year course of one of the longest studies of birds in North America,” reports Sahagún.