WMOD00565

• Title: Snow Augmentation Research Needs - A History of Weather Modification in Colorado
• Date: 6/1/1982
• State: CO
• Weather Modification - Doc Type: Report

The San Juan Ecology Project, held concurrently with the Colorado River
Basin pilot Project, assessed the environmental impacts of snowpack and of
the silver iodide (AgI) used to seed the clouds.

The findings of the San Juan Ecology Project indicated little deviation ~n
effects of 10 to 20 percent snow increases from the large natural
variability (over 400 percent) in snowpack. Increases in the amount of
silver iodide resulting from seeding were inconsequential compared to the
amount of silver naturally present in the environment. While the San Juan
Ecology Pro ject showed no significant short term environmental effects from
winter seeding, results might be different in the long term. Measurements
over many more years are recommended to assess the effects of prolonged use
of seeding agents and increased snowfall on the ecosystem.

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Catalysts for New Research

o Significant technological advances in weather measuring equipment such
as radiosondes, radiometers, and radars have been made in the years
since the Climax and Colorado River Basin pilot Project studies were
completed. The new equipment promises more precise findings for cloud
physics research.

o Increasing concern over future Colorado River water supply and the
potential for new knowledge are incentives for future study of the
physical cloud processes and the human dimension questions raised by
winter seeding.

Order of Question Importance for New Research

In what order should the physical and societal questions surrounding weather
modification be addressed? Many questions are asked repeatedly. From a state
regulatory perspective there is strong inclination to address first those

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