INYO SUGGESTIONS ALL WET
Published in the May 23, 2026 issue.
There was an answer for nearly every question… and then a casual acknowledgment that the suggestions being put forward didn’t carry as much water with the Los Angelese Department of Water and Power (LADWP) as Inyo County and local water watchers had hoped.
The May 7 Inyo-LA Technical Group meeting discussion about groundwater pumping levels ended with LADWP holding firm on its initial proposed pumping levels in Inyo County at between 54,310 and 81,360 acre-feet (AF).
The Inyo County Supervisors had requested pumping just 46,540 AF, which was also the recommendation of the Inyo County Water Commission. Both groups maintained LADWP’s groundwater extraction should only supply water to in-valley uses, from irrigation to mandated environmental mitigation. They were also hoping for some assurance that the Inyo groundwater would not be exported to Los Angeles via the LA Aqueduct.
After listening to staff from the Inyo County Water Department and the public, Eric Tillemans, interim LA Aqueduct manager, said the department saw no reason to reduce its pumping plan for the 2026-27 water year. He said the plan was in line with the mandates of the Long-Term Water Agreement (LTWA).
Tillemans responded to numerous questions and issues raised by Inyo County and the public regarding the pumping plan.
The runoff credited to 2025-26 hit 79% of normal, about 322,000 AF. The big March melt boosted runoff for 2025-26, with the snowpack shrinking from nearly 100% on March 1 to just 29% on April 1. Tillemans said that was only the third time in 100 years when nearly the entire Sierra snowpack melted in March.
The fourth straight year of higher or nearly average runoff meant that average groundwater levels in Inyo County “are above baseline,” Tillemans said, even accounting for the predicted drop in groundwater this year.
There have been no changes in the “on-off status” of the 22 groundwater wells linked to vegetation monitoring sites. Two wells remain in “off status,” and can’t be pumped, and 20 are in “on status” as defined by the LTWA and are available for pumping.
The decidedly fuzzy question about whether groundwater ends up being exported in the aqueduct was not cleared up.
The department has no way to track water once it is out of the ground and flowing, Tillemans said. Looking at the question from another angle, he pointed out the big picture answer was “zero,” since the amount of surface and pumped water LADWP supplies for in-valley uses, about 95,000 AF, is higher than the amount of pumped groundwater (54,310 to 81,360 acre-feet).
That 95,000 AF total does not include an additional 60,000 AF diverted for use on the Owens Lake Dust Mitigation Project.
Tillemans outlined why LADWP shifted years ago from a single pumping number to the range of totals. He said the department needs “flexibility” in case, for example, conditions are dryer then normal so it can still meet its obligations in the Owens Valley and Los Angeles. Further downstream, LADWP water system managers need to plan for a range of available water from the Eastern Sierra and other sources. Tillemans added that LA city officials want to be assured there will be adequate water for the city.
Eastern Sierra water exports via the Los Angeles Aqueduct in 2026-27 will total an estimated 227,000 AF. That represents about 47% of the year’s total water use for Los Angeles (an acre foot of water, 326,000 gallons, can supply a year’s worth of water for two households).
Pumping totals at the low end of projections in recent years were primarily caused by operational and infrastructure issues. The aqueduct has been temporarily shut down for repairs or maintenance several times, he said, which impacts all Owens Valley water operations. This spring, the system’s reservoirs filled quickly, so that also lowered the need for pumping.
A persistent question centered on a past general agreement between Inyo County and LADWP that using vegetation monitoring to manage pumping is not the best approach. Tillemans said both sides did hold preliminary discussions on possible changes to managing pumping. However, LADWP “was not in favor of managing around groundwater levels,” Tillemans said.
Since both sides have to agree to any changes to the LTWA, that ended the discussion.
Regarding pumping’s impact on vegetation, Tillemans defended the LADWP approach, and did not concede that in all cases groundwater pumping is directly linked to a loss of vegetation. For instance, in Laws, a wellfield targeted for less pumping by the county, Tillemans said the area has “volatile groundwater levels,” which can go up by as much as nine feet in wet years then drop by several feet in dry years.
While pumping is like a straw taking water out of an aquifer, runoff and spreading are like a faucet that puts water into the aquifer, he said.
“Hydrology plays a part” in wellfield and vegetation conditions. Overall, average groundwater levels are “at or above baseline,” he repeated.
Since the Water Agreement went into effect in 1991, yearly groundwater pumping has averaged about 69,000 AF, Tillemans said. The 1991 Environmental Impact Report accompanying the Water Agreement anticipated yearly pumping at 110,000 AF. Before the agreement in the 1970s and 1980s, pumping was as high as 200,000 AF in two years, and was around 100,000 AF for a number of years.
The public will get another chance to comment on the pumping plan during the May 27 meeting of the Inyo-Los Angeles Standing Committee, starting at 11 a.m. in the Inyo Supervisors meeting room in Independence. The committee is made up of elected and appointed officials from Inyo and LA.
