Published in The Mammoth Times on June 24, 2021
Twenty seven years after the California State Water Board’s decision to protect Mono Lake by limiting Los Angeles’ water diversions, a combination of environmental changes and water diversion changes have left the lake eleven feet below the Water Board’s established management level, less than halfway to its projected goal. “We’re… at the edge of a lot of really troublesome, worrisome situations for the lake and its ecosystem and recreation,” said Geoff McQuilkin, executive director of the Mono Lake Committee, an environmental nonprofit dedicated to restoring and protecting the lake.
According to Maureen McGlinchy, Hydrology Modeling Specialist at the Mono Lake Committee, a combination of factors can be attributed to the eleven foot difference between the Water Board’s expectations for the lake, and its current level. The main factors include a decrease in Sierra Nevada runoff and precipitation around the lake, possible increase in evaporation rates, and the Los Angeles Department of Water and Power’s unexpected success in diverting the maximum amount of water allowed every year since the Water Board decision. When looked at alone, none of these factors are outstanding, but their impact becomes clear when added up over time. For example, the small 2% decrease in Sierra Nevada runoff over 26 years is actually the equivalent of around 85,000 acre feet of runoff, about two total feet of lake elevation.
Given these factors, Mono Lake currently sits 6380.9 feet above sea level, 1.5 feet lower than last year. In large part due to last year’s watershed runoff of only 49% of average, and the predictions for this year’s to fall around 58% of average, the lake is predicted to fall below 6380 next year. The implications of this drop are frightening, according to McGlinchy and McQuilkin. “We know that Mono Lake is at risk when the lake is low,” said McQuilkin. “When you’re in a drought, on top of being in the era of climate change, all the risks of the past are still risks, like the land bridge being exposed, giving predators access to a nesting colony of gulls.” Another implication of the low lake level on local conditions, McGlinchy said, is the worsening of air quality. “Since the lake is lower, more of the lakebed is exposed, and with wind events… we have Clean Air Act violations,” she said. In addition, as the lake falls, its ecosystem comes closer and closer to danger, endangering the millions of migratory birds that depend upon it.
However, advocates for the lake have not given up hope. “There’s one part of the Mono Lake water balance that we Californians have control of, and that is the water diversions,” said McGlinchy. The Water Board will soon hold a hearing to reassess the guidelines for reaching management level, and there, many hope, a combination of science, collaboration, and love for the environment will assemble a new path towards saving Mono Lake.