Frequently Asked Questions

Q. What is a drought?

A. A drought is a period of drier-than-normal conditions that results in water-related problems.

Q. What causes droughts?

A. Drought occurs when not enough rain falls to the ground.

Q. When does a drought begin?

A. The first evidence of drought usually is seen in records of rainfall. Although several weeks, months, or even years may pass before people know that a drought is occurring.

Q. Does a shortage of rain mean that a drought will occur?

A. Yes, a period of below-normal rainfall may result in drought conditions. Soils can lose moisture and dry conditions can develop.

Q. Can drought affect the water level in wells?

A. Yes, droughts affect the height of the underground water levels due to the extreme deficit of rain combined with excessive water use.

Q. What was California's driest year on record?

A. The driest single year was 1977. Statewide, runoff was only about 15 million acre-feet, representing 21 percent of the average annual amount.

Q. When was California's last major drought?

A. California's last major statewide drought was 1987-92. At the regional level, parts of Southern California experienced a series of consecutive dry years in the late 1990s/early 2000s, with the 2002 water year setting records for being the single driest precipitation year in such cities as Los Angeles and San Diego.

Q. What is a "water year"?

A.The water year extends from October 1st through September 30th. "Water year 2009" means October 1, 2008 through September 30, 2009. Water agencies such as the Department of Water Resources or the U.S. Geological Survey often use this period to track and report hydrologic data.

Q. Can we predict when the next drought will occur in California?

A. No. Although significant progress has been made in climate research that helps us understand oceanic and atmospheric conditions associated with drought, the many factors associated with drought make it too hard to accurately perdict.

Q. What have been the largest cutbacks in deliveries of impacted water in California?

A. In 1991, the U.S. Bureau of Reclamation's Central Valley Project reduced agricultural water deliveries by 75 percent and urban deliveries by 25 percent. The Department's State Water Project zeroed out agricultural deliveries and reduced urban deliveries by a minimum of 70 percent.

Q. What is the Palmer Index?

A. The Palmer Index (more properly called the Palmer Drought Severity Index) uses temperature and rainfall information in a formula to determine dryness. It has become the semi-official drought index. Visit the website for more information. www.drought.noaa.gov/palmer