Even as winter and early-spring storms have filled reservoirs to the brim and piled snow on Sierra Nevada mountaintops, state and federal officials say they’re limited in how much water they can send south of the Sacramento-San Joaquin River Delta.

California's lead water agency on March 20 set anticipated deliveries to contractors at 70 percent of requested supplies. The Department of Water Resources’ (DWR) update came a few days after the U.S. Bureau of Reclamation announced that agricultural operations north of the Sacramento-San Joaquin River Delta will receive their full supplies while south-of-Delta ag contractors will receive 55 percent.

Both the state and federal allocations are assessed monthly, with the final allocation coming as late as May. The State Water Project's (SWP) deliveries are already set to be double those of last year, when the final allocation was 35 percent.

"A 100 percent allocation is rare even in wet years due to Delta pumping restrictions to protect threatened and endangered fish species," DWR spokeswoman Maggie Macias tells Western Farm Press in an email. "The last 100 percent allocation was in 2006. Prior to 2006, it had been 30 years since there was a 100 percent allocation."

Many factors have limited the federal Central Valley Project's (CVP) ability to provide higher or full south-of-Delta deliveries even in wet years, asserts Christie Kalkowski, a spokeswoman for Reclamation's Mid-Pacific Region. They include regulatory constraints and limited capacity in reservoirs and canals, she says in an email.

CARRYOVER WATER

However, in addition to this year's allocation, some CVP water remains in the San Luis Reservoir as a carryover supply from last year, she says. A new contract year began on March 1, she adds.

"This water is not part of this year’s allocation, but is CVP water that is available for those water contractors’ use this spring," Kalkowski says. "We're developing and updating estimates about how much of that allocation is available as we process the carryover requests we’ve received, as well as ongoing spring use and other factors, so we don’t have an exact number at this moment.

"We can note that for 2019, water contractors were allowed to carry over up to 10 percent of the CVP water allocated to them last year into this contract year, although the final number that was requested to be rescheduled is likely to have been less than that," she says.

Winter storms that swept through California enabled statewide snow-water equivalents to exceed their averages for April 1, which is considered the peak date in terms of snowpack levels, by mid-February. The statewide Sierra snowpack as of April 9 was 161 percent of average, according to the DWR’s California Data Exchange Center (CDEC).

The state's snow-water equivalent has nearly tripled since Feb. 1. Snow water equivalent is the depth of water that theoretically would result if the entire snowpack melted instantaneously. Regulators ay it is an important tool used by water managers across the state to estimate anticipated spring runoff.

The DWR’s Northern Sierra 8-station index has recorded above-average precipitation for water year 2019. While the state has not reached record precipitation like that seen in 2017, February was the third wettest recorded in the Northern Sierra index since 1921 and the sixth wettest in the San Joaquin index since 1913, according to the agency.

RESPONDING TO RAIN

During breaks in the weather in mid-March, agricultural aviation companies saw a surge in business from tree crop farmers who wanted to treat for fungus that can result from rain but were unable to take tractors into their orchards, the California Farm Bureau Federation (CFBF) reported.

The storms have rendered almost all of California free from drought, according to the U.S. Drought Monitor. Only San Diego County, large portions of Orange, Riverside and Imperial counties and northern slivers of Siskiyou and Modoc counties were still abnormally dry as of April 2.

Most of the state’s major reservoirs are at or above their historical averages for this time of year. Lake Oroville, the SWP’s largest reservoir, was at 82 percent of capacity and 105 percent of average on April 9, according to CDEC. The DWR began using the Oroville Dam’s refurbished main spillway for the first itme last week, with expectations of releasing as much as 20,000 cubic feet per second (cfs) to make room in the lake for more stormwater and runoff.

Shasta Lake, the CVP's centerpiece reservoir, was at 92 percent of capacity and 111 percent of its historical average as of April 9, the state's water agency reports. San Luis Reservoir, the largest off-stream reservoir in the United States where water is stored for the SWP and CVP, was at 98 percent of capacity and 108 percent of average. In Southern California, SWP’s Castaic Lake was at 88 percent of capacity and 98 percent of average.

“With full reservoirs and a dense snowpack, this year is practically a California water supply dream,” DWR Director Karla Nemeth told reporters after the agency's latest manual snow survey last week. “However, we know our long-term water supply reliability cannot rely on annual snowpack alone. It will take an all-of-the-above approach to build resiliency for the future.”

ALLOCATIONS A BOOST

The DWR’s 70 percent allocation was a boost from the 35 percent announced in February. The updated CVP allocations on March 15 were an increase from the 70 percent and 35 percent, respectively, announced in February for contractors north and south of the Delta. The Friant Division’s allocation is 100 percent for Class 1 water.

However, the fact that most San Joaquin Valley growers will still receive less than their full contracts after two of the last three winters have been extraordinarily wet provides more fuel for farm groups pushing for water policy reforms.

Growers and industry groups blame the 27-year-old Central Valley Project Improvement Act and subsequent environmental laws and judicial decrees for drastically reducing pumping from the Delta.

They point to hundreds of thousands of acres on the valley’s Westside that have been left fallow in recent years because more and more surface water has been left in-stream for imperiled fish.

One solution should be to build more storage so that more excess water in wet years could be carried over, the groups say.

“Despite a much-above-average snowpack, many California water users will still face water shortages in 2019,” California Farm Bureau Federation President Jamie Johansson says. “That underlines the need to improve our water infrastructure, so we can make more efficient use of water for both our economy and environment.”

CALL ON CONGRESS

The CFBF was one of more than 100 organization representing water and agricultural interests in the U.S. that recently urged Congress to use any infrastructure package under consideration to help address severe hydrological conditions in the West.

Groups including Western Growers, American Agri-Women and Family Farm Alliance joined others from California, Arizona and 11 other states in signing the March 25 letter to key congressional committees and Western senators.

“As a nation we must continually invest in the Western water infrastructure necessary to meet current and future demands,” the groups stated in the letter. “Our existing water infrastructure in the West is aging and in need of rehabilitation and improvement.”

The groups note that President Donald Trump has said infrastructure might be one area that both political parties can agree on. Rep. Peter DeFazio, D-Ore., who chairs the House Transportation and Infrastructure Committee, has said he intends to produce a multi-billion-dollar infrastructure bill to fund transportation and water projects.

The letter adds that water conservation, water recycling, watershed management, conveyance, desalination, water transfers, groundwater storage and surface storage are all needed in a diversified management portfolio.