As a major storm swept across Northern California, providing a glimmer of hope for relief from drought, state and federal officials warned Thursday that at least five more just like it are needed to ease a three-year siege.
The storm soaked the Sierra and Central Valley just as officials were releasing figures showing a near bone-dry February had exacerbated the drought.
"February was very disappointing," said Maurice Roos, chief of hydrology for the state Department of Water Resources. "We're all smiles today to see the kind of storm that we had (but) we're going to need about five more to get us really out of the woods this year."
'Horrible, Just Terrible'
State officials reported that rainfall in February, a critical rain month, was 40% of normal in their tracking areas. In the areas that feed federal reservoirs, officials gauged it at a "horrible, just terrible" 18% of normal.
To maintain water deliveries to urban and farming areas supplied by the federal and state governments, officials said March would have to produce double the normal precipitation. Federal officials, who predict that the chances of sustained heavy downpours are slim, have already begun cutting back deliveries to Central Valley farmers and some Northern California cities served by federal water projects.
William J. Helms, drought response coordinator for the state Water Resources Department, said his agency will decide by May 1--the official end of this rainy season--if it needs to order cutbacks. In that case, he said water deliveries to agricultural regions will be reduced by 40% and there will be no reductions to cities.
'Classified as Critical'
"All this still hinges on what happens--how much rainfall we're going to get," he said. "Even if we do get enough water to make our deliveries, the water year will still be classified as critical because it won't have restored the reservoirs."
He said the three-year drought, the first in 400 years of such long duration, had continued to siphon away reservoir reserves. At the beginning of 1987, the state's reservoirs were full because of an exceptionally wet season in 1986. By the beginning of 1988, they were 93% of normal. At the end of February this year, they had dropped to 65% of normal.
Both state and federal officials said the problems in 1988 were heightened not only by a smaller amount of rainfall but an even lower level run-off to feed reserves. When soil is dry, they noted, it absorbs most of the rainfall, leaving little run-off to replenish reservoirs. At the same time, they said, the dry powdery snow in the Sierra that produced wonderful skiing conditions had a below-normal water content.
Roos said he is still hoping that rainfall in March can prevent water delivery cutbacks. He said the latest storm had produced about three inches of rain in the Sacramento Valley, soaking the soil mantle so that any additional storm will produce a heavy run-off. He said another storm system is expected to hit the area Sunday.
"It's the best thing we've seen this year as a single storm. Now we're hoping and praying we get a couple of follow-ups in the next week or 10 days," he said.
But John B. Budd, a spokesman for the federal Bureau of Reclamation, did not share the state official's optimism.
"There are a lot of things working against being positive about what's going to happen the remainder of the year," he said.
Three-quarters of the rainy season is already over, he pointed out, and last year March, like February, was exceptionally dry.
Cutbacks in water supplied by state and federal governments will not directly affect Los Angeles and other cities in Southern California. Los Angeles, however, may experience its own shortages because of reduced snowpack in the eastern Sierra Nevada, one important source of the city's water.