WMOD00446

• Title: Utah Cloud Seeding Program - Increased Runoff/Cost Analyses
• Date: 2/1/2000
• Weather Modification - Doc Type: Report

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UTAH CLOUD SEEDING PROGRAM

Increased Runoff/Cost Analyses

Summary

From the analyses in this report, the estimated average annual increase in runoff
due to cloud seeding in Utah is 249,600 acre-feet. This is an average annual increase of
13.0 percent. The estimated project cost for the 1999-2000 season is $254,300. The
resulting cost per acre-foot is about one dollar ($1.02).

Introduction

The Utah Legislature passed the Utah Cloud Seeding Act in 1973. Utah has
operated a cloud seeding program since 1974. The program is run by local sponsors
contracting with a weather modification company to provide the cloud seeding operations.
The state provides financial assistance to these sponsors ranging from 30 to 50 percent
of project costs, based on the availability of state funds and the magnitude of local projects.

The purpose of this study is to estimate the amount of runoff developed by cloud
seeding and the cost per acre-foot. The procedures used to make these estimates are:

1. Estimate the total average annual runoff from the areas that are being
seeded (target areas).
2. Estimate the increase in April 1 snow water content due to cloud
seeding, based on target and control analysis.
3. Determine the relationship (equations) between annual runoff and
April 1 snow water content for major gaged rivers and streams in the
target areas.
4. Estimate the increase in average annual runoff due to cloud seeding,
based on 1, 2 and 3 above.

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