State Water Officials, Fearing Dry ‘88, Delay Estimate of Availability

State Water Project operators, hoping that welcome storms rolling through Northern California may ease the threat of a dry 1988, Tuesday delayed making a required estimate of the amount of water available to Californians next year.

Officials of the Department of Water Resources said that postponing their initial estimate until Dec. 15 will give them two more weeks in which to calculate new rainfall and the newly started snowpack in the northern Sierra Nevada.

This, in turn, will enable them to make a more realistic projection of the volume of water available for delivery chiefly to State Water Project customers in Southern California and growers in the San Joaquin Valley next year.

Various predictions have cautioned that unless California, particularly the vital watershed basins in the north, receives significant rainfall coupled with a substantial snowpack, 1988 could be a critically dry year. Some have talked of a situation similar to the drought of 1977.

Last year was rated as critically dry, and precipitation so far this year has been less than normal.

Dave Heitzeman, acting chief of the water project’s analysis office, said he is hopeful--”depending on how much faith you put in weather forecasters”--that Northern California storms which began in earnest Sunday will produce enough precipitation to head off a large shortage of water to project customers.

The department is required to make an initial estimate each Dec. 1 of how much water it figures will be available to water project customers, such as the Metropolitan Water District of Southern California. The estimate is updated monthly until the official rainy season ends in April.

But the initial estimate is based on precipitation in October and November. Admittedly conservative projections are then made assuming that precipitation for the remainder of the water year will be the same as it was in 1977, the driest year on record.

Heitzeman said the deliberately conservative estimates are aimed at making sure that municipal, industrial and agricultural users are given an estimate that “is not too optimistic so that we have to pull water back later in the year.”

He said department officials met last week with representatives of water project contractors and it was mutually agreed that delaying the initial estimate to include the current series of northern storms would “provide a better picture to look at.”

“As we get to Dec. 15, we will have more water in the bank than we would have if we had approved (the initial estimate) today,” Heitzeman noted.