Thirty Years and No Resolution

by Lynn Boulton

"Wasn't Mono Lake already saved?" Yes and no. The framework was established to save it with the State Water Resource Control Board (SWRCB) Decision 1631 on the celebrated day, September 28, 1994. That decision determined that the lake level should rise to an average elevation of 6392 feet to ensure it will be a healthy ecosystem well into the future. Until the lake reaches that level, it is not saved. Sadly, for the past 29 years Los Angeles Department of Water and Power (LADWP) has taken the maximum amount of water that the stream diversion rules allow, even when they didn't need the water, even when they know that the lake won't rise to the mandated lake level if they do. It has been clear for some time that the rules won't get the lake to where it should be and that they need to be adjusted based on what we know today.

When stream diversions started in 1941, the lake level was at 6417 feet. By 1980 it had plummeted 45 feet, to the lowest that the lake has ever been – 6372 feet. The compromise of 1994 was to raise the lake 20 feet to an average elevation of 6392 feet, balancing the needs of the City of Los Angeles and the needs of a very important ecosystem.

Based on the best hydrological data at the time, the lake was expected to rise to the mandated level within twenty years under the rules spelled out in the decision defining how much water the LADWP could take. There was to be a review of the rules in 2014 if the lake was not coming up as planned. LADWP asked the SWRCB that review be pushed to 2023, which was granted. Twenty-nine years of experience tell us that the lake is not going to reach a lake level of 6392 feet under the current rules. Now entering the 30th year, the lake level is nine feet short of the goal as of February 1, 2024, even though the lake rose almost five feet in the unprecedented runoff year of 2023. The stream diversions have to be temporarily reduced or suspended to allow more water to flow into the lake.

 

Rush Creek flowing into Mono Lake in May, 2023

Rush Creek flowing into Mono Lake 5_2023-CROP

For the past 30 years, LADWP has taken the full amount allowed. They did not voluntary reduce their stream diversions at any time to meet the goal. LADWP took the full amount even in very wet years (exceeding 100% of normal) such as in 1995-98, 2005-06, 2010-11, 2017, and 2023. If any of those gains from big wet years had been preserved, it would have provided a better buffer during a following drought. The more water that goes into the lake, the healthier the lake will be. Those of us that watch the lake start praying during droughts hoping the lake doesn't reach a tipping point and die. We can see green algae develop in the lake, and we count the dead grebes that wash up on the shore from the lack of brine shrimp. It becomes hard to find a brine shrimp to scoop up to show visitors. There are few alkali flies along the shore as well.

The winter of 2016-2017 was a very big winter with an expected runoff of 197% of normal. In that year, LADWP released 4,600 AF of water south of the Haiwee Reservoir to restore groundwater in three locations (Rose Valley, Indian Wells Valley, and Cameron Wash north of Mojave)1 and gave water away to the Metropolitan Water District as well2. Despite having more water than they needed, LADWP still took 4,439 AF from the Mono Basin, while they also receive on average 5,500 AF of water from the Mono Tunnel annually. With the even bigger winter of 2022-2023, LADWP reported at the February 8, 2024 Inyo-Los Angeles Standing Committee meeting that they released 40,000 AF of water in 2023 south of the Haiwee Reservoir where they had spread nearly 5,000 AF in 20173. And again, on January 31, 2024, they took 4,500 AF from the Mono Basin while it poured in Los Angeles from an atmospheric river. They didn't need the water. Their policy is to take every last drop.

LADWP says the lake is at a healthy level now at 6383 feet. It is healthier now than it was this time last year. There was an abundance of brine shrimp this summer to feed the migrating birds that rely on the lake. However, it isn't at a safe level nor a healthy enough level. The SWRCB decision was based on years of research. LADWP's stream diversions have imposed a constant drought on the lake so when a real drought comes along, there is no recourse to save the lake as it drops lower and lower. We hold our breath and hope the drought ends before the ecosystem collapses. We don't know what that tipping point level is. The lake has been fluctuating between 6372 and 6385 feet for decades.

Once the lake rises to the mandated level of 6391 feet, LADWP will be able to take more than 16,000 acre feet of water with conditions that prevent the lake level from dropping below 6388 feet. A lake level of 6388 feet is healthier and more resilient in prolonged droughts than 6383 feet is. The Mono Lake Committee's hydrological modeling shows that the lake level would be at 6418 feet if there hadn't been any diversions. If it weren't for the SWRCB Decision 1631 the lake would have dropped to 6350 feet and we would have lost the ecosystem. That decision can and will save the lake if we don't delay in seeing it through.

Lynn Boulton graduated from UCSB with a BA in geology. Working in an urban area, she led a tread-lightly lifestyle trying to “walk the talk.” After moving to Lee Vining, she brought the Eastern Sierra into the statewide campaign against bobcat trapping, which led to her serving as chair of the Sierra Club’s Range of Light Group in the Toiyabe Chapter.

References

1) https://sierrawave.net/ladwp-runoff-preparations-way-eastern-sierra/

2) https://www.kpcc.org/2017-04-12/ladwp-to-supplier-take-our-extra-water-no-charge

3) https://www.inyowater.org/wp-content/uploads/2024/02/2-8-24-SC-Meeting-Backup-Material.pdf slide 9