Mono Lake’s surface elevation was measured at 6,383.3 feet above sea level.
LOS ANGELES (April 1, 2025) — Today, the Los Angeles Department of Water and Power (LADWP), Mono Lake Committee and others met at Mono Lake to mark the end of the 2024-25 water runoff year and the start of the next in the Eastern Sierra.
Annual Lake Level Measurements
For decades, LADWP conducts its final snow surveys and measures the surface elevation of Mono Lake on April 1. The lake level reading, alongside the annual snow surveys, provides essential data to better inform forecasting and water exports for the City of Los Angeles. Today’s field report at Mono Lake found the surface elevation to be 6,383 feet above sea level.
“While every other Western terminal lake continues to decline in elevation, Mono Lake has, on average, been trending up for the past 30 years, and its elevation today is primarily driven by hydrology,” said Anselmo Collins, LADWP Senior Assistant General Manager – Water System. “Mono Basin overall is now one of the most protected watersheds in the United States, and LADWP is invested in partnerships and programs to further the Mono Lake success story. We are pleased to see that runoff from existing snowpack, alongside ongoing responsible environmental stewardship, is helping to sustain healthy ecosystems.”
Since 1994, LADWP has reduced its water exports from the Mono Basin by 85%. The Department has also invested nearly $50 million to support riparian habitat, fisheries, and wildlife. To read more about LADWP’s ongoing work in the Eastern Sierra, including at Mono Lake, please visit ladwp.com/easternsierra.
Looking Back on the 2024-2025 Runoff Year
The final amount of water exported from the Mono Basin during the 2024-2025 water runoff year was about 11,000 acre-feet. This amount is less than the 16,000 acre-feet allowed by LADWP’s amended water rights licenses issued by the State Water Resources Control Board. The licenses allow for a maximum export of 16,000 acre-feet if the lake’s surface is between 6,380 and 6,391 feet above sea level on April 1, which it was in 2024.
“As a general rule, available supplies should be stored to prepare for future years. Storing additional water, allows LADWP to supply water to a variety of environmental projects throughout the Eastern Sierra and as affordable drinking water to the residents of Los Angeles,” said Adam Perez, LADWP Water Operations Director.
Rain and snowfall patterns have been irregular, with more precipitation falling early in the year in the northern parts of the state. This variability highlights that, although Southern California experienced record-setting storms in recent years, one extremely wet year is not enough to build up a resilient system.
The Importance of Eastern Sierra Water
The Los Angeles Aqueduct water supply, which includes water from the Mono Basin, is vital to the City of Los Angeles’s ability to ensure safe, affordable, stable water for its residents and helps build resilience to natural disasters like earthquakes. Even as Los Angeles continues to expand its local conservation, recycled water, groundwater and stormwater capture programs, water from the foundational Los Angeles Aqueduct will remain critical to build a diverse water supply portfolio.
Water from the Eastern Sierra is imported using the gravity-driven Los Angeles Aqueduct; along the way, it generates clean hydropower for approximately 200,000 homes annually. LADWP’s only alternative sources of imported water are the State Water Project and Colorado River from the Metropolitan Water District of Southern California. Those sources face real challenges — they are overdrawn, environmentally depleted, less reliable, more costly, and require energy-intensive pumping during transportation.
What Comes Next?
LADWP will use the April 1 snow survey information to forecast Los Angeles’ water supply and corresponding runoff, sharing operation plans in the Mono Basin Annual Operations Plan to be released in May 2025.
To read the latest precipitation reports, visit ladwp.com/aqueduct.
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