A drought is a period of drier-than-normal conditions that results in water-related problems. When rainfall is less than normal for several weeks, months, or years, the flow of streams and rivers declines, water levels in lakes and reservoirs fall, and the depth to water in wells increases. If dry weather persists and water-supply problems develop, the dry period can become a drought. For an overview of the latest updates, please click here for the MWDs 2015 Integrated Water Resource Plan.
The History of Droughts in California
- California has been experiencing one of its most severe droughts in over a century
- There are several instances of extended droughts in California’s history. The most significant statewide multi-year droughts occurred during 1918-1920, 1928-35, 1947-1950, 1987-1992, 2000-2002, and 2007-09.
- Typically, California will accumulate more than 53 inches of precipitation statewide over a 30 month period. In the 30 months preceding 2013, the state accumulated only 33 inches
- Presently, water levels in reservoirs in southern California are well below capacity
- Most groundwater levels are significantly lower than normal
- Snowpack levels are low
- Over-pumping of groundwater wells has led to thousands of wells going dry statewide
U.S. Drought Monitor: A weekly updated graphical representation that maps out the extent of the drought throughout the U.S. Each week various agencies (USDA, NOAA, NDMC…) revise the previous updates based on rain, snow and other events, observers' reports of how drought is affecting crops, wildlife and other indicators. Authors balance conflicting data and reports to come up with a new map every Wednesday afternoon. It is released the following Thursday morning.
USGS: As part of the federal government's Open Water Data Initiative, the U.S. Geological Survey (USGS) has released a new website providing a unique and interactive visualization of the California drought that aims to provide the public with atlas-like, statewide coverage of the water shortage and a timeline of its impacts on water resources.