Feather River Basin Cloud Seeding Feasibility

Abstract

North American Weather Consultants performed a feasibility study of a cloud seeding program, on behalf of the California Department of Water Resources, for portions of the Feather River drainage in the northern Sierra Nevada. The primary objectives of the study were: 1) determine areas that would present the greatest opportunity for runoff enhancement; 2) determine the seeding agent and delivery system that will maximize enhancement with minimal adverse social and environmental effects; 3) estimate the increase in runoff to Lake Oroville that enhancement would have produced during years when unused storage in the reservoir would have been available; and 4) determine the feasibility of proceeding to design study and an Environmental Impact Report. Apparent results from other cloud seeding projects in the Sierra Nevada were used to simulate the effects of cloud seeding upon precipitation in the proposed Feather River target area. The modeled increased precipitation was then used as input for the WRENSS hydrology model to estimate the runoff increases due to the seeding. Benefit cost ratios were formulated to assess whether or not a cloud seeding project would be economically feasible. The study demonstrated that there is a technological basis for the successful performance of an operational weather modification program. A preliminary project design was prepared with a cautionary note that a full design should be completed with more detailed investigations in areas that were beyond the scope of this feasibility study; e.g., suspension criteria, evaluation procedures, equipment needs and siting, to name only a few.