Nobody is declaring a state of drought in California, but ...

When snow surveyors headed into the Sierra Nevada on Thursday for the most important measurement of the season, they found only about half the snowpack that is normal for the date.

It could have been a lot worse — considering that the last three months in California have been the driest of any January-through-March period on record, going back to 1895.

It has been a winter of extremes in the state, beginning with an unusually wet November and December and ending with a string of parched months. “It’s like Dr. Jekyll and Mr. Hyde — the changes we’ve had,” said climatologist Kelly Redmond of the Western Regional Climate Center.

Storage in the state’s two largest reservoirs, Shasta Lake and Lake Oroville, is a bit above normal for the date, thanks to the big storms in the Northern Sierra that turned the final three months of last year into the 10th-wettest on record for that region.

But with statewide snowpack at only 52% of the norm for this time of year — when it is usually at its peak — state and federal water managers are expecting below-normal runoff this spring and falling reservoir levels.

Although no one is declaring drought, the state last week cut projected water deliveries to Southern California. And farmers on the west side of the San Joaquin Valley may get only a fifth of the federal irrigation supplies they have contracts for.

The delivery cutbacks have underscored problems with getting supplies through the Sacramento-San Joaquin River Delta, the perennial bottleneck in north-to-south water shipments.

Water officials say protections for the imperiled delta smelt severely restricted delta pumping when the early winter storms were pouring water into the system. Had a controversial diversion system proposed by Gov. Jerry Brown’s administration been in place, they say the big government water projects could have shipped a lot more water south to the San Joaquin Valley and Southern California.

“If we had that delta fix in place, we’d have moved another 800,000 acre-feet plus already,” said Jeffrey Kightlinger, general manager of the Metropolitan Water District of Southern California. (One acre-foot is enough to supply two average families for a year.)

Metropolitan is a major backer — and future funder — of a proposed $14-billion tunnel system, which would carry supplies from the Sacramento River to existing pumps in the south delta. Proponents hope that changing the diversion point will improve the ecological health of the delta and loosen environmental restrictions on pumping. Opponents, who include delta farmers and commercial salmon fishermen, say the answer to the delta’s problems is to take less water from it, not to construct two massive tunnels they fear will increase exports.

Although the State Water Project, which supplies Metropolitan, expects to meet only 35% of contractor requests this year, Kightlinger said Metropolitan has ample reserves stored in the Southland to tide the region over. “We’re in solid, solid shape,” he said.

It is rare that the giant Westlands Water District and other irrigation districts on the west side of the San Joaquin Valley get full contract deliveries from the federal Central Valley Project. But this year’s allocation of 20% is particularly low, eliciting protests that the west side’s farm economy is being sacrificed for the delta smelt.

“The decrease in our water allocation once again demonstrates how broken the state’s water system has become.... Our priorities are misaligned,” Tom Birmingham, Westlands’ general manager, said in a statement. He said fields will be left unplanted for lack of water.

But the west side’s supply picture is not as bad as a 20% allocation would suggest. According to the U.S. Bureau of Reclamation, Westlands and other districts have about 400,000 acre-feet stored in San Luis Reservoir, the south-of-the-delta holding pool shared by the federal and state water projects. More than half of that amount is left over from last year’s deliveries and the rest was purchased from other irrigation districts.

Elsewhere in the Central Valley, farmers with senior rights to large volumes of water on the Sacramento and San Joaquin rivers will get 100% of their contract supplies this year.

Metropolitan is also expecting normal deliveries from the Colorado River, even though the Colorado Basin remains stuck in a stubborn drought. A wet year in 2011 boosted levels of the Colorado’s two main reservoirs, Lake Powell and Lake Mead. Two years ago Powell was the fullest it had been in a decade, raising hopes that the drought was finally easing.

But since then the Colorado’s flow has been well below average. The river system’s total storage is only 54% full, compared with 63% last year.

“We are closer than ever to getting shortage” on the Colorado, Kightlinger said.

bettina.boxall@latimes.com