The Utah Division of Water Resources released an article explaining the fundamentals of cloud seeding and its role in Utah's water resource management. The piece serves as the first in a four-part series exploring how the state aims to bolster snowpack to support various water users.
According to the Utah Division of Water Resources, the state faces unique challenges in managing water resources. The state must balance the needs of municipalities, farmers, ranchers, and other water users while managing population growth, drought planning, and the health of the Great Salt Lake. The division identified cloud seeding as a safe, efficient, and affordable method to bring additional water to the state.
Cloud seeding requires the presence of precipitating clouds with specific properties to be effective. In Utah, these operations take place during the winter months from November 1 through April 30. The division noted that jet contrails at high altitudes are not cloud seeding.
Historically, all cloud seeding in Utah was conducted using ground-based generators located in foothills and higher mountain elevations. These generators rely on perpendicular winds to transport material over mountains to interact with supercooled liquid water. However, ground-based work faces limitations when wind conditions are unfavorable or when winter inversions create a stable atmosphere that prevents material from dispersing.
To address these limitations, aircraft were added to the program. In 2022, an aircraft was introduced for seeding in southern Utah, followed by a second aircraft in 2023. Based on flight time data, the division determined that one aircraft is currently necessary. This aircraft is stationed in St. George and focuses on the Colorado River Basin and Sevier Basin watersheds, though it occasionally operates in Cache Valley, the Wasatch Front, and the Wasatch Back to seed above the winter inversion layer.
Aircraft operations involve using single burn-in-place flares in clouds where temperatures and supercooled liquid water are detected, typically around 13,000 feet. This process enhances precipitation to increase the water supply for the state.
The Utah Division of Water Resources administers the cloud seeding program under the direction of the state Legislature, which provides funding and policy guidance. Established in the 1950s as a strategic water management tool, the program is designed to enhance snowfall in key watersheds. The division stated that the program is a targeted effort to maximize water resources in alignment with legislative directives and proven methodologies.
