Snowfall Has Drought in Retreat : Weather: Not only is snow plentiful, hydrologists at one site find its water content is four times last year’s level.

After six long winters of discontent, California’s water stewards found cause for joy Tuesday in a snowy Sierra Nevada meadow, collecting measurements that suggest the mighty drought may at last be in retreat.

Although they refused to declare the relentless dry cycle over, state hydrologists conducting one of the year’s first snowpack surveys said the results were the most promising they had seen in a decade.

“You can’t help but be exhilarated by this,” said Dave Hart of the state Department of Water Resources, who has been studying the Sierra snowpack for 10 years. “Last year we came to this place and it was almost bare ground. Today we’ve got 78.5 inches of snow. That’s hard to beat.”

The drifts in the El Dorado National Forest were indeed impressive. But the more crucial discovery Tuesday was that the snow’s water content--the source of spring runoff that feeds state reservoirs--was four times last year’s level and twice the average for the location.

Hydrologist Frank Gehrke said the 22 inches of water content is nearly a record for Phillips, located near Sierra Ski Ranch off U.S. 50 at an elevation of 6,800 feet. The only reading that topped Tuesday’s, he said, was logged in late 1982.

“December has been very good to us,” Gehrke said. “It’s great to have this much water content early in the winter. It’s hard not to be very encouraged.”

As they reported their findings, gray skies served notice that a fresh round of storms was on the way. The new fronts are expected to be followed by still more wintry conditions in Northern California over the weekend.

At the state Drought Information Center, predictions of the drought’s demise were politely called premature Tuesday. Storms such as December’s doubleheader would have to continue monthly through March in order to fully compensate for six critically dry years, said spokesman Dean Thompson.

Even if that occurs, some casualties of the drought--such as depleted ground-water basins, forests full of dead trees and badly stressed fisheries--will take six years or more to recover, Thompson said. Still, few could dispute that the winter of 1992-93 is off to an impressive start.

Because much of the precipitation is snowfall that has yet to melt, the storms have not done much for California’s reservoirs, which stood at near-record low levels at the start of winter. The major reservoirs still contain only about half the water they normally hold at this time of year, Thompson said.

Officials declined to speculate how last month’s storms and the encouraging snowpack readings might affect water shipments to customers of the State Water Project. Thompson said any change in the current plan to give project customers only 10% of their requested amounts would be announced later this month.

Amid the frosted pines of the El Dorado Forest, it was difficult Tuesday to fathom that another year of water shortages could lie ahead. Virgin drifts up to eight feet high flanked the highway, giving it the feel of an ice tunnel. Along some stretches, a protruding chimney was the only clue that a house was buried below.

The state has been collecting snow survey data since 1926, using the data to make predictions about water supplies. There are more than 300 stations scattered through the mountains, as well as electronic snow gauges that continually feed information to the state’s computers.

The method used Tuesday is decidedly low-tech and was developed at the turn of the century. Hydrologists stick a hollow aluminum pole into a drift down to the ground, extract a core sample of snow and weigh it to determine the water content.

“It worked great then and it still does,” said Hart.

DOUBLE TROUBLE: Southland braced for two storms. B1