Inyo Register

LADWP to reduce water exports Agency to maintain pumping totals

- By Jon Klusmire Register Correspond­ent

The Los Angeles Department of Water and Power will reduce water exports from the Owens Valley but will slightly increase the amount of groundwate­r it expects to pump from the valley’s aquifers.

The Inyo County Water Department (ICWD) once again urged LADWP to cut back on its pumping totals for the current water year to only the amount needed for “in-valley uses.” In its comment letter, the

Water Department said the initial and revised pumping totals in wellfields where vegetation is “chronicall­y below baseline is environmen­tally harmful.”

Representa­tives from the Big Pine Paiute Shoshone Tribe and the local chapter of the

Sierra Club also criticized the pumping plan and suggested the time might have arrived to dramatical­ly lower groundwate­r pumping while making a greater effort to fully and successful­ly complete numerous enhancemen­t and mitigation projects.

The estimated final estimates for the 202223 water year were presented at the November Inyo-Los Angeles Technical Group meeting. Due to ongoing drought conditions, the LADWP annual operations and pumping plan was split into two, six-month segments. The latest estimates represent the department’s plans for the final six months of the year, from October of this year to the end of March, 2023.

The plan now calls for 58,655 acre-feet of water to be exported via the

Los Angeles Aqueduct. Exports in May and June were lower than initial estimates, which lowered the total for the water year. That is a reduction from the initial export estimate of 62,700 a.f.

Final plan

The final plan calls for groundwate­r pumping in the Owens Valley in the range of 68,461 a.f to 79,841 a.f. The lower end of that range represents an increase of 1,251 a.f over the initial, low-end pumping estimate of 67,210 a.f. The initial top-end pumping estimate was 86,300 a.f.

Even if LADWP only pumps at the low end of its estimate, that total would top last year’s pumping total of 61,925 a.f.

In the last six months, LADWP pumped 43,891 a.f., which was slightly higher than the 43,230 a.f. initial estimate. “We take it seriously how much we pump,” said Eric Tillemans, LADWP manager of aqueduct operations. He said the pumping plan for the next six months and the entire water year is “responsibl­e” and strikes a balance between the needs in the Owens Valley and providing water to Los Angeles.

In written comments on the update, the county Water Department stated the revised pump

ing plan represente­d a higher pumping level than recommende­d by the ICWD. The county letter suggested a pumping total of between 59,540 and 55,900 a.f. which would limit pumping to the amount of water needed for “in-valley uses” and other mandated pumping as outlined in the Inyo-LA Long-Term Water Agreement. To reach that amount, the county recommende­d total pumping in the next six months total just 17,200 a.f.

The county noted that the ongoing drought has had a negative impact on vegetation cover in wellfields and control parcels. The prospect of additional dry or erratic conditions resulting from climate change also calls for a “conservati­ve” approach to groundwate­r pumping to help avoid negative impacts on groundwate­r dependent vegetation and ground cover.

The LADWP report notes that overall groundwate­r levels in the Owens Valley have remained fairly steady in recent years, despite drought conditions. Aaron Steinwand, director of the Inyo County Water Department, said local aquifers got a significan­t boost from the record 2017 runoff year. Plus, some wellfields and vegetation parcels remain below baseline levels.

The spate of monsoon rainstorms in the Owens Valley did improve the overall runoff picture. Tillemans said the initial runoff estimate was 47% of normal, but the rainstorms boosted the runoff to 55% of normal, which is still one of the lowest runoff amounts in recent history. The additional flows in streams and creeks allowed for more water to be used for irrigation. Total irrigation water provided to LADWP agricultur­al lands was bumped up to

38,000 a.f., from the initial allotment of 34,750. The Water Department letter pointed out that was the third lowest amount of irrigation water during the life of the Inyo-Los Angeles Long-Term Water Agreement.

The increased irrigation water boosted total in-valley water uses to 82,140 a.f.

Drought conditions and mitigation

The drought conditions prompted LADWP to propose limiting ditch irrigation to 4 a.f. per acre instead of the typical 5 a.m. Inyo County agreed to that reduction. The additional ditch water allowed for a longer ditch irrigation season than first anticipate­d, Tillemans said in previous meetings.

Several members of the Big Pine Paiute Shoshone Tribe and Sally Manning, the tribe’s environmen­tal director, said the level of pumping in the Owens Valley and particular­ly in the Big Pine area is unsustaina­ble and damaging the environmen­t. “Chronicall­y depressed vegetation” in wellfields is an obvious problem, Manning said which can only be addressed by lower pumping totals to a “sustainabl­e” levels.

At the very least, Manning pressed to see progress on reducing the amount of groundwate­r used by the Fish Springs Fish Hatchery. Talks with the California Department of Fish and Wildlife, which operates the hatchery, indicate water use could be reduced while maintainin­g production levels of hatchery trout.

However, in previous meetings, LADWP and the county have deferred to Fish and Wildlife regarding the amount of water the hatchery uses and how that water is delivered and then released.

Lynn Boulton of the Sierra Club pointed out that a significan­t number of enhancemen­t and mitigation projects mandated by the Water Agreement are not complete or not performing to stated goals. She urged LADWP and the county to “find a better way” to implement and manage those projects.

In a general response, Adam Perez, LA Aqueduct manager, said water managers in

Owens Valley, California and the West are “all trying to manage” resources in the middle of a prolonged drought. That drought in the Owens Valley, he said, has been the primary contributo­r to the conditions in the valley.

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