Drought Conditions

Hydrologic conditions improved in early 2016, but five years of extreme dryness across California means statewide water supply conditions continue to be among the most challenging in decades.

 

The northern Sierra Nevada snowpack remained below normal in early March despite strong El Niño conditions. The situation in early 2016 was better than it was in April 2015, when the water content in the Sierra snowpack was just 5 percent of average, prompting an executive order by the governor to reduce urban water use statewide by 25 percent.

 

 

The Colorado River Basin is somewhat better off than the Sierra Nevada. Precipitation in the Upper Colorado River Basin was about average in February 2016, as was the snowpack – though the river basin has been dry in 11 of the past 16 years.

Water conservation remains important for San Diego County and the rest of the state to comply with state mandates that have been extended through October 2016. However, conservation efforts have been complicated by an extended stretch of abnormally high temperatures. Since October 2013, the average daily maximum temperatures at San Diego’s Lindbergh Field have been above normal almost every month, and in February 2016, they were a record-breaking 9 degrees above the long-term average.


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
Click image above to enlarge.

In May 2015, 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, the initial state mandates required them water-use reductions of 12 to 36 percent compared to 2013 water-use levels, with a regional aggregate conservation target of 20 percent.

In March 2016, state regulators certified the supply of potable water from the Claude “Bud” Lewis Carlsbad Desalination Plant as drought-resilient, reducing the regional impacts of emergency water-use mandates the state imposed in June 2015. Certification by the State Board lowered the regional aggregate water conservation goal from 20 percent to about 13 percent from March through October, though water-use targets continue to vary by local water agency.

As a wholesale water provider, 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. 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.

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 2015, 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 independent water transfers from the Imperial Valley have allowed the Water Authority to offset almost all of the reduction in supplies from MWD in fiscal year 2016. That means the Water Authority has enough water supplies to meet about 99 percent of the typical demands by its member agencies for the year that ends June 30. However, Water Authority member agencies are under state orders to reduce water use by 8 to 28 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 developed the largest seawater desalination project in the nation. The Carlsbad facility started commercial production in late 2015, producing about 50 million gallons per day. The Water Authority also has heavily promoted conservation, helping to drive down per capita potable water use in the region by 39 percent since 1990. Regional potable water use in 2015 was 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.

Water Supply Conditions and Drought Presentations

 

Snapshot of State Response to 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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