WMOD00568

• Project Name: Snowater
• Title: Snow Water Augmentation for the Eastern Slopes of the Rockies - Stage I: Technology Adaptation
• Date: 6/1/1986
• Weather Modification - Doc Type: Report

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1 PROPOSAL OVERVIEW
1.1 INTRODUCTION

Meltwater from mountain snowpack provides the principal water source
(some 75 percent) for most agricultural, urban, industrial and
recreational requirements in southern Alberta. This water resource
provides the means for significant irrigation agriculture in this
region. Its continued supply is central to the maintenance and
continued development of irrigation-based agriculture.

Mountain snowpack results from snow-producing clouds that form over
the mountain regions during the winter months. Considerable quantities
of moisture are contained in the atmosphere as it passes over Alberta.
Because of the forced lifting of the air as it passes over the
mountains, atmospheric moisture condenses to form "orographic" clouds,
which can produce snow. However, if the clouds are warm (-100C) and
shallow they often do not produce snow even though they contain
adequate quantities of moisture. For example, with a moderate westerly
flow in a cloud one kilometer deep extending 100 kilometers (sixty
miles) along the mountains and containing one-tenth of a gram of
condensed water per cubic meter of cloud, five thousand cubic meters
(one million gallons) of water pass over the mountain crests each
minute. Cloud seeding attempts to initiate or enhance snowfall from
these clouds that may otherwise evaporate on the leeward side of the
mountains.

Early efforts to artificially increase mountain snowfall date back to
the 1950's. These initial attempts used dry ice pellets in
experiments on orographic clouds. In the 1970's seeding of winter
orographic clouds with silver iodide and dry ice was accompanied for
the first time by systematic airborne measurements of cloud
characteristics. More than three dozen operational and research
programs in seven western states have been active in snow augmentation
at one time or another since the late 1960's. Major research programs
are presently underway in California, Utah, Nevada and Colorado.
Results of these programs indicate that orographic cloud seeding can
increase mountain snowfall by 10 to 15 percent. These increases
translate into a 10 percent increase in runoff. Recent decisions by
the government of Alberta to increase irrigation water storage
capability" in southern Alberta assure such augmented runoff could be
effectively managed. However, even with this increased storage the
growing demands for water in this region will eventually outstrip the
available natural supplies.

This proposal asks for support for
augmentation technology to Alberta.
Augmentation for Ihe [astern Slopes of
in two stages. SNOWATER I is described
would involve full-scale experimental
to increase snowfall in the mountains.

acquiring and adapting snow
The SNOWATER (~w Water
the Rockies) project would be
in this document. SNOWATER II
seeding to evaluate capability

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