Nevada is a very arid place that supports a fast growing population. For decades, the Desert Research Institute (DRI) has used remote snow generators to seed clouds in northeastern Nevada and the Tahoe region. The program “is aimed at stimulating snowfall in selected mountainous regions of Nevada to increase the snowpack, resulting in more spring runoff and water supplies in the surrounding areas,” but cloud seeding was in jeopardy this year given the recent budget crisis. On Thursday, October 15, 2009, the cloud seeding program’s future was secured with an unanimous vote by the Southern Nevada Water Authority.
Cloud-seeding has been in operation in the Tahoe region since the 1960s. The operation works by:
Primarily, ground-based generators are used to burn a solution of silver iodide, sodium iodide and salt in acetone to release silver chloro-iodide particles which create additional ice crystals, then snow, in winter clouds. Weather conditions are selected to optimize fallout in targeted basins. All generators are remotely operated by radio or cellular telephone. A seeding aircraft is used to augment ground seeding operations. The aircraft releases AgI from pyrotechnic flares or solution burners. Dry ice is also used in airport fog clearing operations.
Current funding for Nevada’s cloud seeding program totals $900,000 for three years to operate seven snow generators. The Las Vegas Review-Journal reports, “According to DRI estimates, cloud seeding on average produces an extra 15,850 acre-feet of water a year in the Ruby Mountains and 6,770 acre-feet a year in the Tuscarora Mountains.” The Las Vegas region is not expected to benefit much from the cloud-seeding program, although J.C. Davis of the Southern Nevada Water Authority explains, “What’s good for the (regional) hydrology is good for us.”
Nevada is not the only state to modify weather conditions with cloud seeding operations. 11 western states, including the headwaters of the Colorado River in Colorado (thanks to DRI supplied equipment) have cloud seeding programs. Critics have accused such programs as simply “stealing it from some other location“.
There are environmental concerns with cloud seeding programs. The silver iodide used in cloud seeding is bio-accumulative in aquatic environments, yet the amounts are “100 times less than industry emissions into the atmosphere in many parts of the world, or individual exposure from tooth fillings”. Furthermore, cloud seeding has been used for other purposes than producing snow, such as preventing precipitation. It has even been used to protect the environment and human health by avoiding the radioactive fallout from Chernobyl. Whether you agree with cloud seeding or not, the program will continue in Nevada.