Currently, about 85 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. However, several challenges are impacting 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 Conservation

Weather Conditions

Despite early winter rain and snow levels that were at or slightly above normal, our imported water supplies are still recovering from historic dry conditions. Many state reservoirs had to be drawn down significantly to cope with dry conditions across California in 2007, and the Colorado River basin will take many years to recover from eight years of drought. As of January 2008, the two biggest reservoirs along the river, Lake Mead and Lake Powell, were still hovering near record-low levels.

Locally, early winter rainfall has provided marginal help to local reservoirs, but not enough to mitigate the San Diego region’s dependence on imported supplies.

It’s possible drier conditions can return and remain in place between now and April 2008, resulting in another below-average year for rain and snow. Another below-average year reduces water available from the State Water Project. Regardless of precipitation levels, court-ordered restrictions on State Water Project pumping are in place and will reduce deliveries of available water to this region in 2008 and perhaps beyond, making meeting the region’s water needs much more challenging.

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
Dry Conditions (Click on "Dry Times Ahead" more link)

Bay-Delta Challenges

Last year, about 34 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.

Recent court and regulatory decisions have severely reduced the reliability of this important water supply. In August 2007, a federal judge ordered pumping restrictions for the SWP and the Central Valley Project (a federal water project) to better protect Delta smelt, a threatened fish. These restrictions went into effect in late December 2007. The Metropolitan Water District of Southern California, the San Diego County Water Authority’s main water supplier, estimates these restrictions may reduce its Bay-Delta water deliveries by as much as 30 percent in 2008. These restrictions may continue long-term.

In addition, in February 2008 the state Fish and Game Commission ordered additional pumping restrictions on the SWP to protect another fish, the longfin smelt.

The actual reduction to the San Diego region’s water supplies depends on several factors, including rain and snowfall levels between now and next spring, how reductions are divided between the state and federal water projects, and how MWD allocates a potential shortage among its member agencies, including the Water Authority.

The Water Authority is working with other water agencies, the Legislature and the Governor long-term solution to the Bay-Delta’s infrastructure, legal and environmental problems that will enable the SWP to safely and reliably convey water supplies to the San Diego region.

More information on the Bay-Delta is available at the following links:

CALFED Bay-Delta Program
State of California’s “Delta Vision”
State Water Project

Enhancing Supply Reliability

At the time of San Diego’s last major drought (1987-1992), 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 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.

Securing New Supplies
Water Transfers: In 2003 the Water Authority reached a 75-year water conservation and transfer agreement with the Imperial Irrigation District. This deal will provide San Diego County with 50,000 acre-feet of highly reliable Colorado River water in 2008. Deliveries will increase gradually to 200,000 acre-feet annually by 2021.

Canal Linings: The Water Authority also signed separate agreements to line 58 miles of agricultural canals with concrete. Under these pacts, water previously lost to seepage is conserved and transferred to San Diego County for 110 years.

The Coachella Canal lining project is complete and now provides 21,500 acre-feet of water annually to the county. Progress on the All-American Canal lining project will allow the transfer of an additional 12,600 acre-feet of water to the county this year. Once completed in 2010, the project will provide a total of 56,200 acre-feet a year.

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 projects now supply more than 40,000 acre-feet of water annually. By 2020, these projects, including a privately developed seawater desalination project in Carlsbad, are projected to supply more than 160,000 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 shortages.

Already complete are 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 from local reservoirs, and to make 20,000 acre-feet in Lake Hodges available during emergencies. Also, plans are under way to raise San Vicente Dam 54 feet to store an additional 52,100 acre-feet of emergency water.

Carryover Storage: In addition to the Emergency Storage Project, the Water Authority has a goal to create 100,000 more acre-feet of carryover storage – surplus water collected during wet periods to be used during drier years. The Water Authority is studying the feasibility of creating this storage by raising San Vicente Dam an additional 63 feet.

Increasing Conservation

Efficient water 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 for more than 15 years.

Now, the region’s water agencies aim to increase conservation water savings from 52,800 acre-feet in 2007 to 94,000 acre-feet annually by 2020.

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

In 2007, the Water Authority held its second annual Water Conservation Summit to work with local governments and water, business, and community leaders on strategies to conserve water. Working from a five-year Blueprint for Water Conservation developed in the first summit held in 2006, the summit participants developed goals and plans for the region in the areas of water conservation, landscape ordinance, public outreach, recycled water and water and energy partnerships.

More information can be found at waterconservationsummit.com.

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.