Currently, about 80 percent of San Diego’s water supply is imported, either from the Colorado River through the Colorado River Aqueduct, or from the Sacramento River-San Joaquin River Delta (Bay-Delta) through the State Water Project. The remainder comes from local supplies. There are challenges that will continue to impact these sources.

Click on the links below to learn more about the factors that are shaping our current and future water supplies.

Weather Conditions
Bay-Delta Challenges
Enhancing Supply Reliability
Increasing Water Use Effeciency

Weather Conditions

Statewide, supply conditions have improved significantly in 2011.  California snowpack conditions were nearly 80 percent above normal at the end of April, and the state Department of Water Resources announced the State Water Project will make 80 percent of its requested deliveries this year – up from 50 percent last year, 40 percent in 2009 and 35 percent in 2008.  Many key storage reservoirs around the state are nearing their capacity.  Governor Jerry Brown ended California’s drought declaration on March 30.

Despite these greatly improved conditions, it is still important for residents and businesses to continue efficient water use practices in the face ongoing supply challenges in the Bay-Delta and the long-term achievement of a state-mandated 20 percent reduction in water use by 2020.

Click on the links below to look up current rain and snowfall totals and water levels in key reservoirs. Daily California Precipitation Totals
Sierra Snowpack Levels
Colorado River Reservoir Conditions
California Drought Conditions
California Reservoir Conditions
San Diego Reservoir Levels

Bay-Delta Challenges

In 2010, about 18 percent of water used in San Diego County came from the State Water Project (SWP). The SWP conveys runoff from the Sierra snowpack in Northern California through the Sacramento River/San Joaquin River Delta (Bay-Delta) to the Harvey O. Banks pumping plant, which pumps the water south to 25 million Californians in communities from the Bay Area to San Diego.

Regulatory restrictions on pumping in the Bay-Delta reduce water supply benefits from wet winters. While the effects of the restrictions have been offset this year because of improved river flows and judicial orders temporarily easing some measures, there is still no long-term plan in place to settle the ongoing water reliability and environmental issues in the Bay-Delta , traditionally the source of up to 30 percent of our water supply. These regulatory restrictions will continue to make our state system for managing water more vulnerable to weather changes. This will make it even more difficult to cope with and recover from dry conditions in the years ahead.

Pumping restrictions to protect endangered fish species in the Bay-Delta region have resulted in reduced water deliveries from the State Water Project by as much as 30 percent, limiting the amount of water that can be stored during wet years. The reduced pumping capacity also means large volumes of water are lost during wet years, greatly limiting the ability of Southern California water agencies to refill reservoirs to help cope with future dry years. Additional restrictions to protect more fish species are possible. It is very possible that these restrictions may continue long-term. More information on the Bay-Delta is available at the following links:

CALFED Bay-Delta Program
State of California’s “Delta Vision”
Bay-Delta Conservation Plan ( http://baydeltaconservationplan.com/Home.aspx ) Delta Plan ( http://deltacouncil.ca.gov/ )

Enhancing Supply Reliability

At the time of San Diego’s last major drought, which lasted from 1987 to1992, the region relied almost completely on a single water supplier, the Metropolitan Water District of Southern California (MWD).

Since then, the San Diego County Water Authority and its member agencies have significantly diversified and improved the reliability of the region’s water supply. Together, they have secured new local and imported water supplies and improved the region’s water infrastructure to provide the region with growing resources and flexibility to cope with dry conditions.

Under state law, the Water Authority is required to prepare an urban water management plan and update it every five years. The most recent update identifies a diverse mix of water resources projected to be developed over the next 25 years to ensure long-term water supply reliability for the region. Since adopting the 2000 plan, the Water Authority and its member agencies have made great strides in diversifying water supplies and enhancing water conservation for the region. The 2010 plan was adopted in June 2011. For a copy of the 2010 plan, click here (http://www.sdcwa.org/2010-urban-water-management-plan).

Securing New Supplies
Water Transfers: In 2003, the Water Authority reached an up to 75-year water conservation and transfer agreement with the Imperial Irrigation District. This deal will provide San Diego County with 80,000 acre-feet of highly reliable Colorado River water in 2011. Deliveries will increase each year to 200,000 acre-feet annually by 2021.

Canal Linings: The Water Authority also signed separate agreements to replace 58 miles of earthen agricultural canals with concrete-lined canals. Under these pacts, 80,000 acre-feet of water previously lost to seepage is conserved and transferred to San Diego County for each year for 110 years. The Coachella Canal lining project provides 24,000 acre-feet of water annually and the All-American Canal lining project provides a total of 56,200 acre-feet a year to the county.

Local Resources: The Water Authority provides financial and technical assistance to member agencies developing or expanding projects such as groundwater recovery and water recycling. Member agency groundwater and recycling projects now supply more than 43,000 acre-feet of water annually. By 2020, these projects, including a privately developed seawater desalination project in Carlsbad, are projected to supply more than 132,000 acre-feet of water annually.

Improving Infrastructure
Emergency Storage Project: The Water Authority is constructing a system of reservoirs, pipelines, and pumping stations that will provide an additional 90,100 acre-feet of emergency water storage capacity for use during disasters or other supply interruptions. Already complete is the Olivenhain Dam and Reservoir. The reservoir stores 24,000 acre-feet of water, 18,000 of which are available for emergencies.

In addition, several pipelines are being built to improve the ability to move water to and from local reservoirs, and to make 20,000 acre-feet in Lake Hodges available during emergencies. Also, the San Vicente Dam Raise project, currently under way, will increase the height of the dam 117 feet. This will allow for an additional 52,100 acre-feet of emergency water storage.

Carryover Storage: In addition to the Emergency Storage Project, the Water Authority’s San Vicente Dam Raise project will create 100,000 acre-feet of carryover storage –– surplus water collected during wet periods to be used during drier years.

In total, the raising of the San Vicente Dam will more than double the capacity of the reservoir, adding an additional 152,100 acre-feet of storage to the region.

Increasing Water Use Effeciency

Efficient water use must be a part of everyday life in the San Diego region to maximize water reliability and minimize energy and capital costs required to meet growing demand. In addition to securing new water supplies and improving infrastructure, the Water Authority and its member agencies have been implementing aggressive water conservation programs over the past two decades.

Now, the region’s water agencies aim to increase water conservation from over 65,000 acre-feet in 2010 to 94,000 acre-feet annually by 2020.

Because landscape irrigation comprises on average, more than half of all urban water use in San Diego County, the Water Authority is placing more emphasis on outdoor conservation.

For beautiful and water-wise landscaping ideas, visit the Water Conservation Garden at Cuyamaca College.

If your community group or organization would like to learn more about the 20-Gallon Challenge, water supply reliability, or other critical water issues affecting the San Diego region, visit our Speakers' Bureau web page or contact Teresa Penunuri, Community Relations Representative at tpenunuri@sdcwa.org to request a speaker. The Speakers' Bureau is a free service to the community.