Water supply

Water from the State Water Project flows to the Valley’s major water suppliers through the California Aqueduct. Although the supply is variable, area water contractors say they have enough supply to meet demand, as long as it is managed with storage during wet years, to get through the dry ones.

PALMDALE — Based on current projections for the next 25 years, water suppliers in the Antelope Valley who depend on State Water Project water flowing through the California Aqueduct will have enough to meet demand, provided they continue to enhance storage and other capabilities to ensure adequate supplies during those inevitable drought years.

Representatives of the Antelope Valley-East Kern Water Agency and the Palmdale Water District — two of the primary State Water Project contractors in the area — presented an overview of water availability to the Antelope Valley Watermaster, on Wednesday.

The Watermaster, the body tasked with over­see­ing the 2015 court sett­le­ment that set limits on ground­water pump­ing for users across the Val­ley, relies on outside water supplies to replace groundwater that has been pumped in excess of the limitations, and many of the parties to the settlement rely on the State Water Project for some or most of their water supplies.

The contractors are allocated certain amounts of State Water Project water each year; however, except in very wet years, they seldom receive the full allocation. For example, for the current dry year, contractors received only 5% of their allocations.

AVEK, the largest contractor in the Valley, is allocated nearly 145,000 acre-feet annually; Palmdale Water District is allocated 21,300 acre-feet and Littlerock Creek Irrigation District has 2,300 acre-feet.

An acre-foot is 325,851 gal­lons, or approximately the amount of water a typ­ical Antelope Valley house­hold used in one year be­fore recent droughts reduced usage.

The state Department of Water Resources predicts the average amount contractors will actually receive to be 58% in the 2020 timeframe, decreasing over the next 20 years to 52%, PWD Resource and Analytics Director Peter Thompson III said.

“I know it can be hard, when we’re in the middle of a drought, to look at that and go ‘Is that realistic?’ ” he said, but the projections look at regulatory restrictions and climate change as factors in coming up with conservative estimates.

Because the amounts received vary so greatly from year-to-year, AVEK and PWD actively engage in transfers, exchanges and water banking to invest excess supplies in wet years, to be called upon during times of drought.

“We’ll be able to balance out that variability in supply through banking,” Thompson said.

Also based on projections from 2025 to 2045, supplies are on track to remain ahead demand, even as supplies grow less and demand increases, AVEK Assistant General Manager Matt Knudson said.

For 2025, supply is projected to be 87,890 acre-feet, with a demand of 44,440 acre-feet. By 2045, supplies are expected to be 81,379 acre-feet, with a demand of 57,590 acre-feet, he said.

These supplies are inclusive of State Water Project and other sources.

Even though the supplies are projected overall to handle the demand, they may be significantly less in any given year.

“This kind of emphasizes … the importance of (water) banking here in the Valley for agencies like AVEK,” he said. “On an average year, our supplies exceed our demand, so we’ve got to ensure that we have adequate banking capacity, storage capacity, as well as recovery capacity through wells to take advantage of the water when it’s available.”

To that end, PWD also depends on a mixture of water supplies, including recycled water and augmentation of the aquifer and leases and transfers of other water.

For PWD, the 2025 projected demand is just under 20,000 acre-feet, increasing to nearly 24,250 acre-feet in 2045. Supplies are projected to total just over 35,000 acre-feet across the projected timespan, but with a different mix of sources.

“We’re actively developing those supplies to make sure that we have that buffer on those average years, so that we can store water and have it available for dry years,” Thompson said. “We’re confident that we have enough excess water supply that we can support replacement water obligations within our service area.”

AVEK’s water storage targets increase from 72,630 acre-feet stored in 2020 to 132,900 acre-feet in 2045.

“We’ve currently exceeded that (2020) target for AVEK,” Knudson said.

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