Desalination: Examining Its Role in Our Water Future

As California continues to grapple with water shortages, desalination remains a topic of interest in the conversation about sustainable water management. While ocean desalination often receives the most attention, brackish water desalination and other water recycling methods also play a critical role in securing a reliable water supply. Understanding the costs, benefits, and feasibility of these processes is essential to making informed water management decisions.

The Reality of Ocean Desalination

Ocean desalination seems like a straightforward solution—convert seawater into fresh water and transport it inland; however, the economic reality tells a different story. The cost of seawater desalination facilities in Southern California can exceed $2,800 per acre-foot, making it one of the most expensive water supply options available. In contrast, the average cost of delivering State Water Project water in Southern California is around $600 per acre-foot—significantly lower and a far more practical solution for meeting regional water needs (Sunding et al., 2023).

Desalination accounts for less than one percent of Southern California’s total water supply due to the high costs and challenges associated with permitting and construction (Sunding et al., 2023). Replacing the volume of water currently provided by the State Water Project to Southern California would require at least 25 additional desalination plants equivalent in size to the Carlsbad facility, which has an annual capacity of 56,000 acre-feet (Sunding et al., 2023). Given these challenges, alternative solutions such as stormwater conservation and water recycling remain more viable and scalable compared to ocean desalination.

Brackish Water Desalination: A Viable Alternative

Unlike ocean desalination, brackish water desalination provides a more cost-effective and practical option. EMWD already operates brackish water desalters in Menifee, treating salt and contaminant-laden groundwater to improve water quality and reliability. This process costs significantly less than ocean desalination while still contributing to long-term water sustainability. Expanding such initiatives could strengthen our local water supply without imposing excessive financial burdens on residents.

EMWD meets nearly 10 percent of its demand through its groundwater desalination efforts, producing more than 14 million gallons of drinking water per day. The recent addition of the Perris II Desalter, which alone provides 5.4 million gallons per day, enhances water reliability for thousands of households (EMWD, 2024). In total, the program serves over 30,000 households annually by treating brackish groundwater and removing approximately 65,000 tons of salt each year, improving long-term water quality.

Investment and Innovation in Water Security

Industry leaders have recognized EMWD’s efforts in desalination. In 2024, CalDesal was awarded the agency the inaugural Institutional Achievement Award for its leadership in advancing groundwater desalination as a sustainable water solution. EMWD has also secured nearly $100 million in grant funding to support the expansion of its desalination program, with significant contributions from the State Water Resources Control Board, the United States Army Corps of Engineers, and other key agencies (EMWD, 2024). These investments ensure the continued growth and efficiency of desalination technology in our region.

EMWD is also working with private companies to pilot cutting-edge desalination technologies aimed at increasing recovery rates to the 90th percentile, further maximizing the efficiency of groundwater treatment (EMWD, 2024). Additionally, while seawater desalination remains a costly option for inland communities, EMWD is exploring potential partnerships to diversify future water supply sources.

A Balanced Approach to Water Management

Desalination, water recycling, and conservation efforts all play a role in ensuring a resilient water future. While ocean desalination remains an impractical solution for inland communities due to its high costs, brackish water desalination, and water recycling offer more viable alternatives. By prioritizing these strategies, we can secure a sustainable and cost-effective water supply for our region.

As someone who has spent decades working in the water industry, I understand the challenges and opportunities we face. My goal is to ensure that our water policies are based on sound science, fiscal responsibility, and long-term sustainability. EMWD’s investments in desalination and water recycling are crucial steps toward securing a reliable future for our communities. By continuing to advocate for innovative solutions and securing funding for these projects, we can protect our water future while keeping costs manageable for our community.

References

Sunding, D., Browne, O., & Zhu, Z. J. (2023, December 14). The Economy of the State Water Project. California Department of Water Resources. Retrieved from https://water.ca.gov/-/media/DWR-Website/Web-Pages/News/Files/FINAL-12-14-2023---The-Economy-of-the-State-Water-Project.pdf

EMWD. (2024, February 8). EMWD Awarded for Desalination Program Leadership. Eastern Municipal Water District. Retrieved from https://www.emwd.org/news/emwd-awarded-desalination-program-leadership

EMWD. (2022, June 22). EMWD Dedicates Third Desalination Facility. Eastern Municipal Water District. Retrieved from https://www.emwd.org/news/emwd-dedicates-third-desalination-facility