NewsDrop July 2023

Airplane in action burning silver iodide flares into a storm cell.

Once absorbed into the cloud, the bonding agent forms several ice crystal nuclei by attracting water molecules. Once they become heavy enough, they become rainfall. In 2022, 57 clouds were seeded over EAA targeted counties, and a total of 0.77 inch of additional rainfall was produced. This additional rainfall equated to 283,500 acre feet of additional rainwater and 3,199 acre feet of additional aquifer recharge. Since 2004, a total of 14.13 extra inches of rainfall resulted from the existing PEP, translating into 3,755,200 acre-feet, an average of 197,642 acre-feet per year.

SINCE ITS INCEPTION, THE COST BENEFIT OF THIS PROGRAM IS ABOUT $0.70 PER ACRE-FOOT OF ADDITIONAL RAINFALL AND IN THE LAST TEN YEARS, THE COST WAS APPROXIMATELY $32 PER ACRE-FOOT OF ADDITIONAL RECHARGE.

Since its inception, the cost benefit of this program is about $0.70 per acre-foot of additional rainfall and in the last ten years, the cost was approximately $32 per acre-foot of additional recharge making it one of the cheapest programs in the EAA’s conservation/ replenishment toolbox. While the results are not drought-breaking, one extra inch of rainfall is beneficial. In 2014 a cost-benefit analysis was completed by Dr. Jason L. Johson from Texas A&M University, and he determined that weather modification has a significant economic impact on EAA counties. One additional inch of rainfall increased dryland crop revenues, increased cost savings on irrigated acres, and increased grazing land values. At that time the direct economic impact for the EAA target area alone was over $2.6 million.

Piper PA-24 Comanche airplane used for cloud seeding.

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