WMOD00297 ‎(2)‎

• Project Name: Project Skywater
• Title: Project Skywater - Fiscal Years 1975-78 Report
• Prepared By: US Department of Interior Bureau of Reclaimation
• Date: 3/1/1979
• Weather Modification - Doc Type: Report

that would permit prediction of the effects of increased snow on the
natural processes of the San Juan Mountains. Although the conclu-
sions of the study are most applicable to the San Juan area, research
approaches permit extrapolation of results to other mountainous areas
of the West. Some of the principles will be applicable to even
broader areas.

Emphasis was on the study of snow-related processes, per se. Thus,
two primary study areas were developed:

(1) Analyses of relationships between snow and various components
of the forest ecosystems, such as forest phenology, phytosociology,
tree biomass and moisture stress, and elk and small mammals; and

(2) A comparable set of analyses of alpine ecosystem components,
including tundra primary productivity, phytosociology and phe-
nology, decomposition, geomorphic processes, and small mammals and
the boreal toad.

To these were added vegetation and geomorphic mapping of the San
Juan Mountain area and investigation of the disposition and
environmental effects of silver iodide. Paleoecology studies
were included in an attempt to understand natural environmental
fluctuations through time.

Study results suggest no immediate, large-scale impacts on the
terrestrial ecosystems of the San Juan Mountains following an addi-
tion of up to 30 percent of the normal snowpack, but with no addition
to maximum snowpacks. ,Furthermore, apparent compensating mechanisms
within the studied ecosystems buffer snow increase impacts, at least
for short periods of time, and are of lesser magnitude than the
changes in snow conditions required to produce them.

Some parts of the mountain ecosystem are found to be more susceptible
to changes in snow conditions than others, so important local effects
are possible. Generally, these susceptible components are very small
parts of the entire system, but their economic or esthetic value may
be much greater than their mass or area suggest. Remedial action is
possible in most such cases but was not specifically studied in this
project. The three components most susceptible to increased snowfall
are:

(1) Snowbank situations at elevations above treeline.
(2) Elk herds.
(3) Some small mammal populations, especially the deer mouse.

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