Unimpressive El Niño leaves California in water limbo

Water rushes down the spillway as it is released from the Lagunitas reservoir in Fairfax, California, on Tues. March 29, 2016. The Marin Municipal Water District is one agency that benefitted from the wet winter. less Water rushes down the spillway as it is released from the Lagunitas reservoir in Fairfax, California, on Tues. March 29, 2016. The Marin Municipal Water District is one agency that benefitted from the wet ... more Photo: Michael Macor, The Chronicle Buy photo Photo: Michael Macor, The Chronicle Image 1 of / 37 Caption Close Unimpressive El Niño leaves California in water limbo 1 / 37 Back to Gallery

The rain storms and blizzards that were supposed to come with El Niño were conspicuously non-biblical in California this winter, leaving the state in an ecological limbo that has regulators thinking about easing water-use restrictions in some places but not in others.

While the weather cheered ski resorts hit hard by the historic drought and brought some reservoirs to their highest points in years, in the end it dropped less snow than average in the Sierra, where more than a third of the state’s water comes from.

The water content of the snow statewide is 87 percent of average for this time of year, according to electronic measurements taken Tuesday, a benchmark when the spring melt historically begins and water spills into the reservoirs.

With El Niño’s biggest deluges hitting the northern part of the state, water officials said that next month they’ll consider relaxing the governor’s unprecedented rationing program, which now requires communities to cut back as much as 36 percent from their 2013 water use.

But much of the southern part of the state has remained as dry this year as it was last year, so any easing of forced conservation might be limited to Northern California.

“The north has really benefited from the winter pattern, but it’s been hit and miss down south,” said David Rizzardo, the chief of snow surveys and water-supply forecasting for the Department of Water Resources. “But the impacts and the problems from drought still persist, particularly in the San Joaquin Valley and farther south. We’re still going to have impacts to farms, including fallowed fields and dry wells.”

The imbalance is a conundrum that water managers, fisheries biologists, environmentalists and agricultural leaders are trying to sort through as the dry season approaches and the El Niño weather pattern fades.

What’s clear is that one mediocre winter is not likely to revive the 58 million trees statewide suffering severe water loss and bark beetle infestations. Salmon, sea lions and aquatic birds — and farmers — will continue to struggle as atmospheric irregularities continue, climate experts say.

“There is no such thing as normal weather and there is no such thing as a normal El Niño,” said Jonas Minton, a water policy adviser for the Planning and Conservation League, which promotes environmental legislation. “All water years are different. What is important for California is how we manage whatever water supplies we receive.”

Sierra snow below average

The monthly snow survey in the Sierra shows that the snowpack is 98 percent of normal in the north, 88 percent in the central part of the state and 72 percent in the south. For the drought to be over, state water officials figured the snowpack needed to be at least 150 percent of normal by April 1. Last year’s measurement on the critical date was the lowest in the Sierra since records began almost a century ago.

While the water situation improved relative to the past few years, the El Niño did not live up to expectations. The event, marked by warm water in the equatorial Pacific feeding moisture into the atmosphere, was indeed strong — among the top three most robust on record. But it behaved differently than El Niños of the past.

“The storm track was enhanced over the Pacific as anticipated, but it was farther north than anticipated,” said Daniel Swain, a climate researcher at Stanford University. “Places other than California got our water, like Washington and Oregon.”

Southern California, which bore the brunt of the big El Niños in 1997-98 and 1982-83, saw just half of average rainfall in many places this winter, including Los Angeles.

“If the trajectory of the storms gets shifted by a little bit, even a few hundred miles, the outcome can be very different,” Swain said.

By contrast, the northern reaches of California more closely paralleled the Pacific Northwest. Eureka received 33 percent more rainfall than average since October, and Crescent City had 22 percent more.

Shasta, Oroville spilling

As a result, Northern California’s big reservoirs are fuller than they’ve been in years, with Lake Shasta at 109 percent of average and Lake Oroville at 113 percent of average — both spilling to make room for spring runoff. Reservoirs farther south, though, aren’t as full as normal, with New Melones Dam on the Stanislaus River at 25 percent of capacity and Pine Flat on the Kings River at 38 percent.

As of Tuesday, rainfall in San Francisco stood at 3 percent above normal for this point in the season. The city, though, gets most of its water from the central Sierra, where snow and rain have also hovered around average.

The vastly different situations across the state have prompted officials at the State Water Resources Control Board to suggest that last year’s sweeping rationing program might need to be shifted. The board has scheduled a public meeting on the restrictions next month, with the expectation of adjusting the regulations in May.

“We’ll be making some changes based on the feedback,” said water board spokesman George Kostyrko. “We’ve been trying to be flexible all along.”

Increased water deliveries

The state and federal water projects that manage California’s big reservoirs are also expected to increase water deliveries to cities and farms in the coming year over last year’s sparse allocations.

The ambiguous drought situation means pelagic forage fish, which salmon and marine mammals such as whales and dolphins depend on, could continue to struggle.

Raphael Kudela, a professor of ocean sciences at UC Santa Cruz, said the storms caused significant runoff along the coast, creating the possibility of more blooms of algae, called pseudo-nitzschia, which spread toxic domoic acid last year and disrupted the crab fishing season.

Although most scientists say the El Niño system is dissipating and the ocean along the equator is cooling, Kudela said the water along the California coast is still much warmer than normal.

“Generally that warm water persistence is continuing to cause problems,” he said, including a “shift toward more warm-water species, which generally don’t support as much growth for salmon and other organisms.”

In general, the recent weather may be an anomaly in California, said Francisco Chavez, a biological oceanographer for the Monterey Bay Aquarium Research Institute. He warned that a long-term trend of drier weather may return this year.

“My forecast,” Chavez said, “is that we will have continued drought — I don’t know how severe that will be — for several years to come.”

Peter Fimrite and Kurtis Alexander are San Francisco Chronicle staff writers. Email: pfimrite@sfchronicle.com, kalexander@sfchronicle.com Twitter: @pfimrite @kurtisalexander