Winter Cloud Seeding Program for Lopez Lake and Salinas Reservoir

Project Contacts

For more information please contact Ray Dienzo via email or Keith Miller via email.

Frequently Asked Questions

What is Cloud seeding?

To put it simply, cloud seeding is a process that takes advantage of weather conditions to increase the amount of rainfall produced from clouds.

How does cloud seeding work?

Cloud seeding helps clouds produce more rain by adding tiny particles to the clouds. Inside the seeded clouds, water vapor freezes onto the particles making the vapor heavier. These heavier frozen particles then fall towards the ground as rain. Cloud seeding does not create new clouds; it increases the amount of rainfall from existing clouds. Cloud seeding typically helps existing clouds produce 10-15% more rainfall than if the clouds were not seeded.

Is cloud seeding safe?

A proposed project does not present a significant safety risk and is not expected to conflict with any regional emergency response or evacuation plan. Other counties, including Los Angeles County and Santa Barbara County, use cloud seeding to enhance their water supply. The County conducted an Environmental Study to identify and minimize any risks.

Does the County currently have a cloud seeding program?

No, the County does not currently have a cloud seeding program, but the County Flood Control and Water Conservation District is proposing one for Lopez Lake and Salinas Reservoir. The proposed project objective is to increase rainfall at Lopez Lake and the Salinas Reservoir during winter storms. The seeding program would use a combination of about eight ground-seeding sites and aircraft. It has been estimated that precipitation increases would be between 9% and 17% in the reservoir areas.

Does cloud seeding harm the environment?

There is no evidence that suggests cloud seeding creates any significant negative environmental impacts. To understand how any potential risks can be minimized, review the Environmental Study released by the County in February 2018.

What materials are used in cloud seeding?

The most common material in cloud seeding is silver iodide.

Contact Public Works via web form, email, or call us at (805) 781-5252.