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

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.

The 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.

Yes, on December 17^th, 2019 the BOS approved a program for the Lopez Reservoir Watershed. The program has the potential to run for three years. The project objective is to enhance rainfall in the upper watershed of Lopez Reservoir. The first year ran January 8, 2020 through April 15^th, 2020. The second year was approved November 17, 2020 and is being conducted between December 1, 2020 and April 15, 2021. The seeding program utilizes a combination of seeding by aircraft and ground-based sites. Year one used aircraft and land sites, year two is using ground-based sites only, and year three is undetermined. It has been estimated that precipitation increases would be between 9% and 17% in the reservoir watershed area.

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.

The most common material in cloud seeding is silver iodide.