The first program objective is to determine the feasibility of increasing precipitation through the aerial application of silver iodide, and second, assuming a reasonable probability of this, to determine if surface water runoff can be increased for Lake J.B. Thomas and E.V. Spence Reservoir located on the Colorado River upstream from Robert Lee, Texas. In addition to increasing precipitation and surface water runoff, the project is designed to enhance rainfall for the agricultural and ranching communities in the target area as a by-product of the operation. Weather Modification's Cessna 340 aircraft was utilized for randomized cloud seeding and cloud physics research. The aircraft carried flare racks that held 100 20-gram silver iodide pyrotechnic flares. These flares normally burn for about 45 seconds and fall about 4,500 feet when ejected at altitudes of 20,000 feet in still air.
Silver iodide is released into the cloud tops if updrafts are favorable.
The radar continuously recorded cloud cell information on magnetic tape. The year's weather modification season occurred from April 15 to October 15. Only 15 cloud seeding missions occurred. During seeded years, the average rainfall for the May to September period for the seeded stations was 14.36 inches, while at the unseeded stations the average was 12.96 inches.