New Assessment of the Economic Impacts from Six Winter Snowpack Augmentation Projects

California has the longest history of continuous operational cloud seeding programs of any area in the world. The technology was first applied by the California Electric Power Company beginning on February 2, 1948. As the years evolved, additional programs funded by water agencies, municipalities and hydroelectric interests were organized over many California locales. During the 2001/02 winter season, thirteen operational programs were active. A broad range of statistical evaluations have been applied to many of these programs. In addition to statistical methods applied to precipitation and streamflow data, these evaluations have also focused on substantial radar data collected by operational 3cm and 5cm weather radar systems. The combined benefits are explored using six programs in California which have been active for various periods since 1950. The results from this study strongly suggest that very beneficial increases in water supplies have been produced by these long-term cloud seeding programs.