EDITORIAL : LESSONS FROM NATURE CALIFORNIA'S LATEST EMERGENCY ILLUSTRATES THE NEED FOR WATER, FLOOD CONTROL IMPROVEMENTS.

WHEN it comes to water in California, it never seems to rain but it pours.

A few weeks ago, the subject on water watchers' minds was shortages. The Great Basin Unified Air Pollution Control District had tentatively adopted a plan that would divert as much as 13 percent of the city of Los Angeles' Owens River water for dust control in the dry bed of Owens Lake near Lone Pine.

Now the problem grabbing the most attention is too much water in the central and northern part of the state.

Tributaries of the Sacramento River were swollen by heavy precipitation in the Sierra Nevada watershed last week, washing out levees and forcing thousands of residents in Yuba City, Marysville and other communities to evacuate. Gov. Pete Wilson once again went through the too-familiar exercise of declaring formal disasters in stricken counties.

Those two incidents - the threatened diversion of part of Los Angeles' water supply and flooding in the north - illustrate the enormous importance of water and flood control projects in this state.

Much of the growth that has occurred during this century in Southern California and the Central Valley was made possible by water projects. Southern California is heavily dependent on water imported from the Owens Valley, the Colorado River and the Sacramento and San Joaquin rivers.

Likewise, irrigation and flood control projects helped turn the Central Valley into one of the most productive agricultural areas on Earth.

But California in recent decades lost much of the will it once had to tame rivers and build aqueducts. Much of the work that was done was accomplished under the State Water Project, which was approved by California voters in 1960. That measure paved the way for the construction of such improvements as the Oroville Dam, the California Aqueduct and Castaic and Pyramid lakes.

Since then, there has been more emphasis on protecting the environment and saving fish and other forms of wildlife. A major goal has been to use water more wisely through conservation and reclamation.

Those are laudable objectives. But improved plumbing often is needed to divert water for environmental improvements and replace supplies that are lost. And floods waste precious water that could have been saved if the state had additional reservoir capacity and more reliable levees and other flood control facilities.

Fortunately, California voters had the foresight to approve a $995 million water measure (Proposition 204) in the Nov. 5. election. Granted, this proposition won't provide much money for conventional water and flood control projects - much of it is earmarked for environmental improvements and studies. But it's a start, especially when it comes to improving management of the Sacramento Delta area, the source of drinking water for about 22 million people in California.

(Water flowing through the Delta also irrigates about 45 percent of the fruits and vegetables produced in the entire United States, according to the state Legislative Analyst's Office.)

Water has been a divisive issue in California for many years, pitting the north against the south, environmentalists against economic interests and cities against rural areas.

However, California as a whole remains threatened by recurring droughts and floods. The current tragedy in the north demonstrates the need for various interests in the state to work together in a responsible way for the benefit of the state as a whole.