Reliable Water Supplies Make San Diego Region Well-Prepared for 2024

Thanks to a decades-long supply diversification strategy and continued efficient use of water across the region, the San Diego County Water Authority announced that the region has reliable supplies to meet demands in Water Year 2024, which started October 1.

Hydrologists use Oct. 1 to begin measuring the snow and rain that will help carry water users through dry summer months the following calendar year. This fall, El Niño conditions continue to strengthen and could bring above-average precipitation to Southern California.

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Water Authority Board Approves 2020 Urban Water Management Plan

The San Diego County Water Authority Board of Directors May 27 approved the Water Authority’s 2020 Urban Water Management Plan for timely submission to the state. The plan highlights how regional investments in a “water portfolio approach” to supply management and a sustained emphasis on water-use efficiency mean that San Diego County will continue to have reliable water supplies through the 2045 planning horizon – even during multiple dry years.

The Board approved the final plan following a public hearing on March 25 and a 60-day public comment period which ended May 6. The final 2020 UWMP will be submitted to the California Department of Water Resources by the July 1, 2021, deadline.

“Successful efforts to create a reliable water supply coupled with the development of new local sources by the Water Authority and its 24 member agencies ensure that the region will weather dry times over the next two decades,” said Water Authority Board Chair Gary Croucher. “We continue to collaborate with our member agencies on investments in infrastructure and local supply sources to benefit the region’s ratepayers now and in future years.”

Collaboration with member agencies

The Water Authority started the current UWMP process in September 2018, coordinating closely with its 24 member agencies, most of which must submit their own plans to the state. Member agencies provided input into the final plan as part of the Water Authority’s ongoing effort to align local and regional projections as closely as possible while still following applicable guidelines and using regional models. The plan’s long-range demand forecast shows an increase in regional demands of less than 1% per year through 2045. This change in demand is consistent with the change forecasted by other large water suppliers in the state, including the City of San Diego and the Metropolitan Water District of Southern California.

Multiple supply and demand projections factor into Urban Water Management Plans, which are mandated by the state to ensure sufficient supplies over 25 years. The plans are not used to set water rates; rates are set annually based on multiple financial factors at the time, not long-term projections about water supplies.

Water supply availability

Urban Water Management Plans are dictated by statutory guidelines, Water Authority Board direction and an agreement with the San Diego Association of Governments to use its regional growth forecast. The plans also support state laws that link approval for large housing developments to water supply availability.

By law, the plans must be updated every five years. Per state guidelines, the Water Authority’s Urban Water Management Plan includes:

  • Projected water demands under normal weather and dry weather scenarios
  • Conservation savings information
  • A process to conduct an annual water supply and demand assessment
  • Supply reliability analysis

The demand forecast accounts for changes in socio-economic factors, such as the number of projected housing units, the mix of single-family and multi-family dwellings, and employment growth.

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The 2020 UWMP highlights the value of the Water Authority’s long-term strategy to invest in highly reliable and locally controlled supplies from the Claude “Bud” Lewis Carlsbad Desalination Plant. Photo: San Diego County Water Authority

Investments in local water supply

Conservation projections account for continued adoption of water-use efficiency measures, compliance with landscape water-use ordinances for new residential construction, and continued installations of sustainable landscapes at existing homes. Since 1991, San Diego County ratepayers have conserved more than 1 million acre-feet of water, and per capita potable water use in the region decreased nearly 50% between fiscal years 1990 and 2020.

The 2020 UWMP also highlights the value of the Water Authority’s long-term strategy to invest in highly reliable and locally controlled supplies from the Claude “Bud” Lewis Carlsbad Desalination Plant and the nation’s largest conservation-and-transfer agreement, which provides high-priority, low-cost water from the Colorado River.

In addition to the UWMP, the Water Authority also regularly updates its Regional Water Facilities Optimization and Master Plan, which focuses on the infrastructure necessary to meet projected long-term demands, and its Long-Range Financing Plan. Those documents work together to ensure the right mix of supplies and facilities to meet the region’s needs at an affordable cost.

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The nation’s largest conservation-and-transfer agreement, which provides high-priority, low-cost water from the Colorado River, is one of several investments that ensures a reliable, plentiful water supply for the San Diego County region. Photo: San Diego County Water Authority

Opinion: Investment in Delta Tunnel, Sites Reservoir Will Ensure Water Supply

California just recorded its’ third driest winter in history, so it’s no surprise that State Water Project deliveries have been cut to just 5% of contracted amounts.

This is bad news for regional water agencies who collectively depend on the State Water Project for a fourth of their water supply.

But these agencies have seen the climate change writing on the wall for a long time. In fact, Southern California has been in an extended drought for the last 20 years. Because of this, 11 San Bernardino Valley water agencies have identified close to $650 million worth of local stormwater capture, storage and recycling projects they plan to build over the next 50 years to lessen their dependence on State Water Project imports.

Water-Use Efficiency, Investments Protect Region as Drought Impacts Spread

Board Chair thanks ratepayers, member agencies

 May 11, 2021 – “Governor Newsom’s latest drought emergency declaration is a grim reminder of the growing water supply challenges across California – and of the value of three decades of our collective dedication to use water efficiently combined with strategic investments that protect San Diego County from dry years. Thanks to efforts of ratepayers, the Water Authority, and our 24 member agencies, we have sufficient water supplies for 2021 and the foreseeable future. Our regional adoption of water-use efficiency measures is a major piece of our strategy, with per capita water use falling by almost half over 30 years. At the same time, the rates we pay for water have been invested in new water sources along with major dams and reservoirs that are showing their worth more with each passing day.” – Gary Croucher, Board Chair, San Diego County Water Authority

Opinion: How San Diego County’s Water Supply Investments Protect Our Economy and Quality of Life From Drought

Increasingly ominous signs suggest that we are entering another multiyear drought in California. The State Water Project recently reduced projected water deliveries for 2021 from 10% of requested supplies to 5 percent, and on April 21, Gov. Gavin Newsom declared a regional drought emergency in the Russian River watershed in Northern California.

But it’s a different story in San Diego County.

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Drought: Why Water Supply Diversity is Critical

Drought is back in California. Federal and state agencies are warning of potential water shortages in the months ahead. Because of investments made by the San Diego County Water Authority, its member agencies and the region’s water ratepayers, San Diego County is safe from the threat of multiyear droughts.

“We are now facing the reality that it will be a second dry year for California and that is having a significant impact on our water supply,” said DWR Director Karla Nemeth in early April. “The Department of Water Resources is working with our federal and state partners to plan for the impacts of limited water supplies this summer for agriculture as well as urban and rural water users. We encourage everyone to look for ways to use water efficiently in their everyday lives.”

The San Diego region relies far less on supplies from Northern California than in previous decades. A severe drought in the early 1990s forced the region to confront the fact that continuing to provide safe and reliable water demanded a diverse portfolio of supplies instead of near-total reliance on a single source.

“We have sufficient water supplies whether it’s a normal year, which means normal rainfall,” said Jeff Stephenson, water resources manager at the San Diego County Water Authority. “A single dry year. Or a period of five straight dry years. Under those scenarios we have more than sufficient water supplies to meet the needs of the region.”

Investments and planning pay off

Stephenson credits three decades of efforts by the Water Authority and its 24 member agencies to diversify water sources, including contracts for water transfers with the Imperial Irrigation District and the Claude “Bud” Lewis Carlsbad Desalination Plant, as well as the development of additional water storage capacity in the region.

There are also several water reuse or recycling projects in development throughout San Diego County. The region’s dependence on imported water supply will decrease as these local supply sources are developed and become operational.

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Construction is underway for Pure Water Oceanside, one of three potable reuse or recycling projects in San Diego County that will reduce the need for imported water while creating a sustainable, local supply. Photo: City of Oceanside/Jeremy Kemp

Approximately 43,000 acre-feet of recycled water is expected to be reused within the Water Authority’s service area annually by 2025. As the new and expanded potable reuse plants come online, they are projected to produce more than 112,000 acre-feet per year of new drinking water supplies by 2045, enough to meet nearly 18% of the region’s future water demand.

“Our member agencies throughout the region have developed more local supplies, such as recycled water,” Stephenson said. “In addition, the member agencies are developing potable reuse projects, including the city of San Diego’s pure water program which comes online in the future, and all of those supplies really make the region much more able to withstand drought periods.”

Revised drought contingency plan

As a result of the persistent drought conditions, and in accordance with its permit for the long-term operation of the State Water Project, DWR has submitted a revised Drought Contingency Plan to the California Department of Fish and Wildlife. The plan provides updated hydrologic conditions and outlines areas of concern for the joint operations of the State Water Project and the Central Valley Project, water quality, and environmental impacts.

In late-March, the State Water Resources Control Board mailed approximately 40,000 notices to water right holders, warning of persisting dry conditions and asking them to plan for potential shortages. Officials said the warnings, a result of two years of below average precipitation and below average state reservoir levels, will prompt early action to help minimize short term drought impacts.

“Planting crops and other decisions that are dictated by water supply are made early in the year, so early warnings are vital,” said Erik Ekdahl, deputy director for the Water Board’s Division of Water Rights. “These letters give water users time to prepare and help minimize the impacts of reduced supplies on businesses, farms and homes.”

The agency suggested in the letter that agricultural water users can implement practical actions now to improve their drought resilience, including reducing irrigated acreage, managing herd size, using innovative irrigation and diversifying water supply portfolios. Urban water users can conserve by putting in drought-resistant landscape, reducing outdoor irrigation and replacing older house fixtures and appliances with more efficient ones.

Increasing local supply sources

The San Diego County Water Authority and its member agencies continue to increase local supply sources and make investments to ensure a plentiful, safe, and reliable water supply for the region’s 3.3 million people and its $245 billion economy.

“Current conditions are a reminder of why the Water Authority and its member agencies have invested in locally controlled water sources and facilities such as dams and pipelines that can move water when and where it’s needed,” said the Water Authority’s Stephenson.

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The Carlsbad plant uses reverse osmosis to produce approximately 10 percent of the region’s water supply; it is a core supply regardless of weather conditions, and it is blended with water from other sources for regional distribution. Photo: San Diego County Water Authority

Ever since the drought of the early 1990s, the San Diego County Water Authority and its 24 member agencies have been leading advocates for water-smart strategies such as low-flow toilets, low-water landscapes and other conservation tactics. One result is that per capita water use in the San Diego region is down by more than 50% over the past three decades.

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“We are now facing the reality that it will be a second dry year for California and that is having a significant impact on our water supply,” said DWR Director Karla Nemeth in early April 2021. Graphic: California Department of Water Resources