Why desalination can help quench California’s water needs

If you’ve ever created a personal budget, you know that assigning your money to different investment strategies is a crucial component to meet your financial goals. When you stop dipping into your savings account each month, savings can begin to build.  

Understanding why desalination is so critical to California’s water future is a lot like building a personal budget. With a changing climate, growing population and booming economy, we need to include desalination in the water supply equation to help make up an imported water deficit.

The California Natural Resources Agency, California Environmental Protection Agency and Department of Food and Agriculture recently released the Water Resilience Portfolio. In it, officials highlighted the importance of diversifying water supplies through the introduction of new water sources and preparing for new threats, including more extreme droughts. 

The authors of the report recognized that we need to look at all the tools in the water supply toolbox and cite seawater and brackish water desalination as an opportunity to support water supply diversification and reduce our dependence on historically less reliable rainfall and snowpack.

These recommendations reinforce what we have known for a long time. Desalination provides a pure source of long-term, drought-proof water that improves the dependability of local water supplies by reducing demand on stressed resources. In California, that includes the Colorado River, the Bay Delta and over-subscribed groundwater basins.

An excellent example of how desalination can enhance water supply resiliency is the Claude “Bud” Lewis Carlsbad Desalination Plant in San Diego County which came online in 2015. 

The plant produces up to 54 million gallons per day of high-quality drinking water. It is San Diego County’s largest single local water source and its only source not dependent upon snowpack or rainfall. That makes it a critical safeguard against future droughts and a crucial part of the region’s strategy to diversify and increase local supplies.

In addition to enhancing local supply, recent technological advancements have made desalination a much more cost-effective and viable solution for meeting growing water demands.

Experts anticipate that as desalination costs continue to go down, the costs of pumping water hundreds of miles could continue to rise and become more expensive than desalinated water in the coming decades.

At a cost of less than a penny per gallon, the Carlsbad Desalination Plant is proving to be cost competitive with other new local supplies being pursued in the region. It is also financially stable due to a public-private partnership and water purchase agreement that include important ratepayer protections, which ensure customers don’t pay if water isn’t delivered.

Additionally, advancements in technology like energy recovery devices help reduce energy consumption and related greenhouse gas emissions. Further, the Carlsbad plant is the first major infrastructure project in the state to offset its carbon footprint.

Recognizing the need for a drought-proof water supply, efforts are already underway to develop several other seawater desalination facilities throughout California.

These include the Cal Am Desalination Project in Marina, the Doheny Ocean Desalination Project in Dana Point, the West Basin Ocean Water Desalination Project in El Segundo and the Huntington Beach Desalination Project.

As we work to build a secure water future, we need to utilize all existing supply strategies including increased conservation, reuse, and both brackish water and seawater desalination into the mix. 

Like a smart investment strategy that recognizes no single investment can achieve financial stability alone, a diversified strategy that includes desalination with other supply sources is an environmentally sound and sustainable way to ensure a resilient water future for all Californians.

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Wendy Ridderbusch is executive director of CalDesal, a unified voice for brackish and ocean water desalination and salinity wendyr@caldesal.org. She wrote this commentary for CalMatters.