(ABC4) – With over 90% of Utah in severe drought, natural rainfall and snow may not be enough to help the beehive state rebound from the water deficiencies that residents are facing. Water modification, commonly known as cloud seeding, may be the answer to some of the state’s drought problems.

Cloud seeding has been around since the 1940s and countries around the world including the U.S. have been utilizing the unique ability to “make it snow” in areas that are facing severe drought issues.

According to the Wyoming Water Modification Program, cloud seeding is the application of scientific technology that can enhance a cloud’s ability to produce precipitation. The technique is an environmentally friendly way to produce more precipitation from clouds in the form of rain or snow.

How does it work? The process works by introducing tiny particles that create additional droplets, or ice, causing the precipitation process to accelerate and also improving the cloud’s efficiency.

Utah has been utilizing cloud seeding since the early 1950s according to the Utah Division of Water Resources (UDWR). The Cloud Seeding Act of 1973 gave authority to the Utah Division of Water Resources to oversee state cloud seeding projects according to the UDWR’s website.

Ground-based seeders, which are used for the treatment of low-level clouds over complex terrain, shoot silver iodide into winter clouds where it helps form ice crystals. The seeders are placed among foothills and higher elevations where the release of the cloud seeds is timed so that air currents carry them high into the cloud.

The UDWR says the process is effective because clouds are formed by water vapor and dust. 

“Under certain natural conditions, those water droplets will freeze together around the dust or other particles and, when heavy enough, will fall from the sky as snow. Often, there is more snow that can fall but limited by the number of particles around which ice crystals can form. That is why adding particles, or seeds, facilitates and accelerates the process which may lead to more snow falling than would have under natural conditions.” the UDWR website states.

With snowpack representing Utah’s largest reservoir, increasing the amount of snow that falls is a win for the water supply.

Cloud seeding can work, but only under the right conditions.

Cloud seeding can only occur when there is sufficient water in the atmosphere, which is why Utah’s cloud seeding takes place only in the winter.

The UDWR says statistical analysis shows an average increase in precipitation of 5-15% in seeded areas at a cost of about $2.18 per acre-foot for the additional water. The field program runs from November to April and is funded jointly by the state and local water interests. 

The map below gives an overview of where cloud seeding occurs throughout Utah.

Courtesy: UDWR