Preparing for California’s Next Drought—Changes Since 1987-92

Preparation of this report was initiated in response to the unusually dry conditions experienced through January 2000. California was in the second year of a La Niña event, typically characterized by dryer than normal conditions in the southern part of the State. December 1999 was one of the driest Decembers on record. Snowpack levels in early January in the northern Sierra, the source of much of California’s developed water supply, were only some 20 percent of seasonal average.

Given that California had previously experienced a record five consecutive wet years, it seemed probable that 2000 would not be another wet year.  Subsequently, climatic conditions demonstrated the great variability typical of California. Substantial precipitation and snowpack accumulation brought Northern California to near average water conditions before the end of February.

A dry 2000 would not have constituted a drought for most Californians, especially not with storage in the State’s major reservoirs at above average levels as a consequence of the past five wet years. It was recognized, however, that planning should begin for actions to be taken in the event that the following year was also dry. In response to the substantial public interest created by the dry weather conditions, the Department evaluated water supply conditions, changed circumstances since the last drought, and other factors that would affect drought readiness in 2001.

The purpose of this report is to review items that the Department should consider in near-term drought planning, putting California’s conditions today into perspective with experiences gained in the 1987-92 drought. The report begins with an overview of California hydrology and water supply, then describes conditions encountered in the 1987-92 drought.

Changed conditions since that drought are summarized, and their implications discussed. The report concludes with a list of actions that the Department could take to respond to future drought conditions.

It is essential that California prepare for the return of very dry conditions. On June 9, 2000 Governor Davis and Interior Secretary Babbitt announced a “Framework for Action” as the completion of a five-year planning program to implement specific actions of the CALFED Bay-Delta Program.

The Framework included a recommendation that Governor Davis appoint a panel to develop a Drought Contingency Plan by the end of 2000. This report will be used to brief the panel on drought actions considered to date, with the expectation that further and more focused actions/programs may be included in the Governor’s Drought Contingency Plan.