As of Tuesday, Jan. 1, Shasta Lake north of Redding, the largest reservoir used by the federal Central Valley Project, was at 73 percent of its 4.5 million acre-foot capacity — 115 percent of average for the date.
The Central Valley Project conveys water throughout the Central Valley via a series of canals and reservoirs, including the Delta-Mendota Canal near Patterson.
Bill Harrison, general manager of the Del Puerto Water District, which provides water for about 45,000 acres of farmland on the West Side, is pleased with the large snow pack but still uncertain what it will mean for local growers.
“It’s a good start to a good water year,” Harrison said. “We’re hoping that it continues, and we’re hoping to take advantage of good precipitation for farmers over here on the West Side. At the same time, we continue to have concerns about constraints to our water supply.”
Farm water districts have had their allocations curtailed for nearly two decades as the U.S. Bureau of Reclamation seeks to protect endangered and threatened fish.
One of those fish is the Delta smelt, a small endangered fish that scientists say is an indicator of the overall health of the Stockton-San Joaquin Delta. In addition, the National Marine Fisheries Service provides protection for the threatened Chinook salmon and Central Valley steelhead.
Environmentalists say these fish are sucked into intake pumps used to divert water to farmers and other state and federal contractors.
The smelt was listed as a federally protected fish in the revised Endangered Species Act of 1993. More recently, the U.S. Fish and Wildlife Service issued a biological opinion in 2008 that provided guidelines for pumping restrictions. A federal judge overturned the document in 2010 after it was challenged in court by farm water advocates, and it was revised as part of a settlement between the different legal parties last year.
Similarly, the National Marine Fisheries Service issued a biological opinion in 2009 that outlined pumping restrictions to protect threatened salmon.
Farm water districts that contract with the Central Valley Project, including the Del Puerto district, received only 40 percent of their allocations in 2012, though even in average rain years it’s typical for farmers to receive less than 100 percent of their contracts.
State Water Project contractors, such as the Oak Flat Water District in the hills west of south Patterson and Crows Landing, received 65 percent of their allocations.
A newly completed 500-foot-long canal that connects the federal Delta-Mendota Canal and the California Aqueduct west of Tracy has helped ease the movement of water to state and federal water contractors when needed, but local farm water districts still face water supply challenges, Harrison said.
Looking ahead, state officials are discussing a couple of tunnels that could carry up to 9,000 cubic feet of water per second from the Sacramento River around the lower reaches of the Delta and avoid the problem of sucking fish into the pumps.
That project would keep much fresh water from flowing into the Delta, but could resolve issues for growers south of the pumps. The project is estimated to cost $13 billion.
In the meantime, Harrison said local farm water districts could face challenges this year even in the best case.
“I think we’ll be surprised, given how wet we’re starting out ... how little (allocations) will turn out, given the constraints that are in place,” Harrison said.
Wet fall, wet winter
In addition to a healthy snow pack in the Sierra Nevada range, local rainfall has been heavier than during the 2011-12 rainy season.
As of Monday, Dec. 31, the Patterson area had received 7.18 inches for this rainfall season, according to a weather station set up at Yancey Lumber, at 100 E St. That compares to 6.85 inches slightly less than a year earlier on Jan. 6, 2011, according to Irrigator archives.
Rainfall as well as the snow pack in the Sierra Nevada range boosts the level of the San Joaquin River, which provides part of the water supply for the Patterson and West Stanislaus irrigation districts, both of which irrigate farms on the West Side.
“I think everyone’s pretty cautiously optimistic right now,” Peter Rietkerk, general manager of the Patterson Irrigation District, said of the heavy rainfall last month and the healthy snow pack. “However, if everything stopped right now, there would be a lot of concern.”
The river reached 32.75 feet in the Patterson area Wednesday, Jan. 2, compared to about 32.5 feet a year earlier, according to the state Department of Water Resources.
Looking to the week ahead, January should start off dry, but local residents could see rain during the weekend.
The National Weather Service predicts clear skies until Saturday, Jan. 5, and Sunday, Jan. 6, when cloudy weather and a slight chance of showers are expected, according to Karl Swanberg, a forecaster for the National Weather Service.
He said rainfall at the nearby Modesto City-County Airport was 4.03 inches as of Dec. 31, about twice what it was the prior year, when it was 2.04 inches.
“This year has been much wetter,” he said.
Contact Jonathan Partridge at 892-6187, ext. 26, or firstname.lastname@example.org.