The Big Thirst : State Report Warns That Demands for Water May Make Shortages Common by the Year 2020

Unless a greater effort is made to better manage the state’s water resources, most Californians by 2020 will cope with water shortages not just in drought years but in normal rainfall years as well, a new state report predicted Wednesday.

The shortages will be more frequent and severe as population growth and environmental protective measures increase the demands on existing supplies, according to the long-range assessment.

“If things (are) not done to change the situation there could be a chronic water shortage,” Water Resources Department Director David Kennedy said at a news conference.

The report predicted that Southern California could be especially hard hit.

By 2020, annual water shortages in the Southland will be about 400,000 acre-feet in average rainfall years and 1 million acre-feet in drought years, the report says.

By that year, the region’s population is expected to soar to more than 25 million, requiring an additional 1.5 million acre-feet of water each year.

Yet as that need increases, the report says, Southern California can expect a reduction in supplies from the Colorado River, the source for more than half of the supplies used by the Metropolitan Water District of Southern California, which in turn provides nearly 60% of the water used by almost 16 million people in Los Angeles, San Diego, Orange, Ventura, Riverside and San Bernardino counties. Other customers--notably Arizona and New Mexico--will be drawing more from the river.

The new assessment of the state’s water future came in a two-volume draft report updating the California Water Plan, a document that is revised every five years. In this year’s revision, the Water Resources Department for the first time provided precise figures to quantify the anticipated imbalance.

The report will be formally presented to the Legislature after the public has commented on it during a series of hearings in January and February. The first hearing in Southern California is scheduled for Jan. 6 in Santa Ana.

State officials emphasized that shortages are likely even with contemplated water management measures such as increased conservation, the retirement of agricultural land and the construction of several new reservoirs.

With California’s population projected to grow by 2020 to 49 million--a 19-million increase from the 1990 level--the report said shortages statewide are expected to range from 1.6 to 3.6 million acre-feet in average years and from 2.5 million to 4.5 million acre-feet in drought years.

The increased demands on supplies, the report said, will come from urban users, particularly in the fast-growing South Coast, and new environmental protective measures that require more water to be released for endangered species.

It predicted, however, that agricultural demands for water would decline as more and more farming land is forced out of production by urban growth.

Although the report made no specific recommendations, Kennedy said one possibility is greater use of the large ground water basins in the Central Valley. He said the basins have the “potential to be a significant factor in the future” provided that supplies will be protected from overuse.

“What we have done is describe the magnitude of the problem that we all have to address to make sure that these (shortages) do not develop,” Kennedy said. “The state has a lot of water . . . the challenge is to manage it to meet all the needs that society wants to meet--the environmental, the urban and the agricultural.”