In summary

Water agencies need to invest in infrastructure and plan for drought to diversify their water supply portfolio and increase reliability.

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By Heather Dyer, Special to CalMatters

Heather Dyer is CEO and general manager of San Bernardino Valley Municipal Water District,

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.

In reality, most local agencies need to plan for drought in Northern California, Southern California or both. In order to diversify their water supply portfolio and increase long-term reliability, the San Bernardino Valley Municipal Water District is investing in projects designed to improve the State Water Project’s ability to capture, store and deliver both Sierra snowmelt and stormwater runoff from unpredictable rainfall events which are predicted to increase as the climate continues to change.

One example of this is the proposed Sites Reservoir. This 1.5-million-acre-foot reservoir will be built near the Sacramento River in Colusa County. The project is designed to capture and store water from the Sacramento River in wet years and release it in dry years to those agencies via the State Water Project.

The Sites Reservoir will increase the collective ability of the project partners to capture and store water, regardless of whether it is snowmelt or rain. The reservoir could yield about 240,000 acre-feet of water per year for agencies participating in the project — enough water to sustain 1 million to 2 million households per year.

The San Bernardino Valley district and 27 other California water agencies have committed funds to design and build the $3 billion reservoir, which is also supported by state and federal funding. Construction of the Sites Reservoir is expected to begin next year, with completion targeted for 2029.

The Valley District and other State Water Contractors have also committed funding for the proposed Delta Conveyance Project, a tunnel that will carry water underneath the Sacramento-San Joaquin Delta. The tunnel is needed to protect precious State Water Project supplies from contamination due to levee failures from earthquakes or rising sea levels, while minimizing environmental impacts.

Valley District is legally entitled to import up to 102,600 acre-feet of State Water Project water each year. But court-ordered water set-asides and regulations to protect endangered species and other natural resources in the Sacramento-San Joaquin Delta have reduced the amount of state water delivered to Southern California agencies by up to 1 million acre-feet per year. These court orders and regulations have reduced Valley District’s ability to import water by approximately 18% – enough water to satisfy the annual water needs of about 72,000 people. 

The Delta Conveyance Project essentially eliminates our impacts on endangered fish, which eliminates the losses associated with delivering our water through the Delta. It also ensures the long-term reliability of Valley District’s imported State Water Project supplies, which currently flow through the Sacramento-San Joaquin Delta.

The Delta is the most vulnerable area of the State Water Project because it is comprised of century-old levees that could collapse in an earthquake and allow salt water to contaminate State Water Project water.

Originally an estuary where Northern California’s waters flowed into the San Francisco Bay, farmers took over the Delta in the 1870s and built 1,100 miles of levees to convert much of the Delta into farmland. The Delta is also the transit point where fresh water from Northern California’s rivers flows into aqueducts that transport the water to Central and Southern California.

State officials see the Delta Conveyance Project as the best option to protect State Water Project water from salt water contamination as it is transported through the Delta. The Delta Conveyance Project is expected to cost about $16 billion with construction expected to begin in 2024 and continue to about 2034.

Because we depend on imported State Water Project water for a fourth of our water supply, we can’t afford not to protect the significant investments we’ve made in developing this supplemental water supply from Northern California. That protection comes in the form of the Sites Reservoir Project and the Delta Conveyance Project.

Preparedness for the future requires looking at improving our imported supplies while also building out local infrastructure to maximize the water resources from our immediate area. By incorporating both of these elements Valley District will ensure a reliable, sustainable supply to the people we serve for decades to come.

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