30th anniversary of the water rights decision to protect Mono Lake

Throughout the year the Mono Lake Committee is celebrating the 30th anniversary of the decision that established the mandate to protect Mono Lake at the 6,392 foot elevation level—the Public Trust lake level. Decision 1631 was issued by the California State Water Resources Control Board 1994 and is the cornerstone of Mono Lake’s protection.

When the State Water Board voted unanimously to approve D1631, the crowd in the Sacramento hearing room stood in a genuine and enthusiastic ovation, a rarity for state agency decisions. Board member Marc del Piero pronounced: “Today we saved Mono Lake.”

D1631 placed limitations on the excessive water diversions that the Los Angeles Department of Water & Power (DWP) had been taking for more than 50 years. Without those limits, Mono Lake would have continued its precipitous decline, its salinity would have risen beyond the tolerance of the brine shrimp and alkali flies at the core of the ecosystem, and its vital role in the lives of millions of nesting and migratory birds would have ended.

Not one of the 16 parties that participated in the State Water Board’s hearing that led to D1631 appealed the decision—most notably, not even DWP. This was due to an agreement to implement major local water supply programs with millions of dollars in state and federal funding that the Committee had helped to secure. A decades-long water battle had ended with all parties agreeing to stop fighting and move forward to implement the solution.

The vision laid out in State Water Board Decision 1631 of Mono Lake up at the healthy, mandated level of 6,392 feet in elevation is possible to reach with adjustments to DWP’s stream diversions. As a start, this year the Mono Lake Committee has asked DWP to not increase diversions.

Reflecting on D1631 today, its importance is clear, but it is also clear that its promise remains unfulfilled. Mono Lake is eight feet shy of the Public Trust lake level—30 years of observation confirm that the lake is stuck at this low level because of the volume of ongoing stream diversions. Thus, it’s appropriate that in this anniversary year the Committee has asked DWP to not increase stream diversions—to make good on its role in D1631’s goal of Mono Lake rising to the Public Trust lake level.

We celebrate this historic decision by reaffirming our commitment to implementing the protections D1631 promised. True success for Mono Lake comes when the Decision’s expectations become landscape realities, with a thriving ecosystem, safe bird habitat, clean air, and secure future.

This post was also published as an article in the Summer 2024 Mono Lake Newsletter. Top photo by Andrew Youssef.