Santa Ana Watershed Project Authority Begins First Year of Cloud Seeding Pilot Program to Increase Local Water Supply

January 9, 2024

Riverside, CA – The Santa Ana Watershed Project Authority (SAWPA) conducted the first cloud seeding events of the Santa Ana River Watershed Weather Modification Pilot Program during recent storms in late December and early January. The Pilot Program, launched in November 2023, is intended to evaluate the effectiveness of enhancing local water supplies through cloud seeding in the region. If shown to be effective, cloud seeding can enhance the watershed resilience of the Santa Ana River Watershed by increasing snow and rainfall from storms by 5-15 percent in targeted areas.

The Santa Ana River Watershed, spanning portions of Riverside, San Bernardino, and Orange Counties, plays a vital role in supporting diverse ecosystems, providing water resources, and offering recreational opportunities to millions of residents. Recognizing the importance of enhancing and preserving this valuable natural resource, SAWPA initiated the Pilot Program to provide an additional source of water supply to adapt to the impacts of climate change risks and help sustain the health of the watershed.

SAWPA collaborated closely with local water agencies, government agencies, and community stakeholders on planning and implementing the 4-year Pilot Program targeting areas across the watershed. The cloud seeding program involves the release of silver iodide particles from ground- based units during storm events to increase ice and snow formation in clouds resulting in additional precipitation. Cloud seeding was performed during three storms during the last week of December and first week of January.

Over a 4-year period, cloud seeding will be validated as a tool in advancing water supply reliability for the region by enhancing our local supplies. The additional water produced through cloud seeding would support natural habitat and be captured by existing stormwater infrastructure that is critical to recharging local groundwater aquifers used for water supply.

“These initial cloud seeding events represent a milestone for the Santa Ana River Watershed Weather Modification Pilot Program,” said Jeff Mosher, General Manager for SAWPA. “The program underscores the commitment of SAWPA to evaluate new local water supplies. If proven viable through this pilot study, cloud seeding could help support a more sustainable future for the environment and communities in the Santa Ana River Watershed.”

The Pilot Program is a 4-year evaluation and validation effort that will allow SAWPA to investigate the increase in water supply from cloud seeding and the potential benefits for the region. SAWPA will monitor and evaluate the program’s implementation, ensuring that the efforts align with the project’s objectives and the needs of the region.

SAWPA encourages the community to stay engaged and informed about efforts under the Pilot Program. Regular updates and outreach efforts will be provided through various sources, including the SAWPA website, social media, and public presentations.

For more information about the Pilot Program and SAWPA’s ongoing initiatives, please visit or contact us at



The Santa Ana Watershed Project Authority (SAWPA), a public water agency was formed as a joint powers authority and is located in Riverside, California. SAWPA focuses on a broad range of water resource issues including water supply reliability, water quality improvement, recycled water, wastewater treatment, groundwater management, brine management, and integrated regional planning. SAWPA’s mission is to manage the Inland Empire Brine Line and to develop and maintain regional plans, programs, and projects that will protect the Santa Ana River basin water resources to maximize beneficial uses within the watershed in an economically and environmentally responsible manner. To learn more, please visit

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