Drought Conditions

After four years of extremely dry conditions across California, statewide water supply conditions are among the most challenging in decades. The snowpack water content in the Sierra Nevada on was just 5 percent of average on April 1, prompting an executive order by the governor to reduce urban water use statewide by 25 percent. Current hydrologic conditions are much better in the Colorado River Basin than they are in the Sierra Nevada. Inflows into Lake Powell this year will be about 95 percent, though the river basin remains mired in a multi-year drought.



Water conservation is urgent for San Diego County and the rest of the state to comply with state mandates and save water in case drought conditions extend into 2016. However, conservation efforts have been complicated by an extended period of abnormally high temperatures. The average daily maximum temperatures at San Diego’s Lindbergh Field every month except one since October 2013.

Northern California’s Lake Oroville is a critical part of the State Water Project, one of San Diego County’s main sources of supply. Drought conditions have significantly lowered storage in reservoirs statewide. Photo courtesy of the Department of Water Resources


Average Daily Maximum Temperature at Lindbergh Field - Departure from Normal (F)
Click image above to enlarge.

On May 5, the State Water Resources Control Board adopted emergency statewide regulations that set water-use reduction targets for local water agencies from June 1 through February 2016. For the Water Authority’s 24 member agencies, state mandates require them to reduce their water use by 12 to 36 percent compared to their 2013 water-use levels.

As a wholesale water agency, the Water Authority coordinates drought response actions for San Diego County to foster consistency while minimizing harm to the region’s $218 billion economy. To address the state’s targets, the Water Authority’s Board limited irrigation of ornamental landscapes and turf grass with potable water to no more than two days a week across the region. Member agencies have the flexibility to set their own watering days and times. The Water Authority’s Board also adopted a package of conservation and outreach measures to help homes, businesses and member agencies decrease water use.

MWD Storage Reserves (End of Year Balances*)
Click the image above to enlarge

For information about water-use rules by community, go to www.sdcwa.org/drought-restrictions.

In addition to the state mandates, the Water Authority faces a 15 percent reduction in supplies from the Metropolitan Water District of Southern California, which supplies about half of the San Diego region’s water. Starting July 1, MWD cut water supplies to the Water Authority and its other customers by 15 percent because of reduced deliveries from the State Water Project and shrinking storage reserves.

Local investments in reliable water supplies such as the Carlsbad Desalination Project and independent water transfers from the Imperial Valley will allow the Water Authority to offset almost all of the reduction in supplies from MWD in fiscal year 2016. That means the Water Authority expects to have enough water supplies to meet about 99 percent of the typical demands by its member agencies for the year starting July 1. However, Water Authority member agencies are under state orders to reduce water use by 12 to 36 percent, regardless of available water supplies.  

Current drought conditions are the most severe since the early 1990s, when the Water Authority was almost entirely dependent on MWD for water and reduced supplies to the San Diego region by 31 percent for 13 months. Since then, the Water Authority and its member agencies have been steadily diversifying the region’s supply sources. One element of that strategy has involved securing independent Colorado River water supplies through a historic conservation-and-transfer agreement with the Imperial Irrigation District in 2003.

In addition, the Water Authority and Poseidon Water are developing the largest seawater desalination project in the Western Hemisphere. The $1 billion Carlsbad Desalination Project is expected to produce 50 million gallons per day starting late this fall. The Water Authority also has heavily promoted conservation, helping to drive down per capita water use in the region by 31 percent since 1990 – and 24 percent since just 2007. Regional potable water use in 2015 is projected to be 21 percent lower than it was in 1990, despite adding 800,000 people to the county.  Over that period, more than 300,000 jobs have been added to the local economy, and the county’s annual gross domestic product has grown by more than 90 percent.

The combined effect of the region’s diversification efforts is that today MWD provides about half of the San Diego region’s water supply, down from 95 percent in 1991. Those investments paid dividends from July 2009 to April 2011 when the Water Authority reduced drought-induced cutbacks from MWD by nearly half.


Snapshot of State Response to 2014 Drought
Click image above to link to ACWA's drought level map.
U.S. Drought Monitor - California
Click image above to enlarge and zoom into detailed California drought map.
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