WMOD00422

• Project Name: Colorado River Enhanced Snowpack Test
• Title: CREST - Environmental Assessment and Design Phase - Finding of No Significant Impact
• Date: 4/1/1981
• Weather Modification - Doc Type: Report

The second 5-year phase would feature a randomized seeding program in a
single subbasin. It would emphasize both the evaluation of seeding
techniques and the quantification of the water produced. Additional
studies in the other candidate subbasins would provide information to
facilitate seeding activities over the entire Basin. Ground-based
seeding studies would be conducted to determine its reliability.
Basin-wide operations could be initiated after satisfactory completion
of this phase.

The advantages of the IO-year program include additional time to develop
and install equipment, prepare environmental and social documents, and
conduct public involvement. Additional time to develop an operation
design is provided. The disadvantages of this option are that a decis-
ion on the long-term use of weather modification as a major source of
augmentation would not be made in the shortest possible time; secondly,
there would not be a potential increase in the Basin water supply for at
1 east 5 years.

2. a-year Program

In this option, the initial phase is reduced from 5 to 3 years, during
which existing technology, techniques, and instrumentation would be
adapted into a design for a subsequent two-subbasin demonstration phase.
Two subbasins would be instrumented for field operations in order to
help compensate for the reduced time of this option. Project equipment,
personnel, and seeding modes would be tested during calibration studies.
The delivery techniques of the ground-based generators would be tested.
Environmental and social impact studies would be conducted.

The 5-year second phase would include a randomized seeding program in
two subbasins to evaluate and quantify water supply increases possible
over the entire Basin. Additional physical measurements would be taken
to obtain information needed to optimize precipitation increases from
cloud seeding. Concurrent studies would be conducted in the remaining
subbasins to obtain information to determine under what conditions the
seeding methods used in this phase could be transferred to other sub-
basins, or what modifications would be required.

The advantages of this option include increased water supply in two
subbasins would be available after 3 years. Also, the intensive two-
subbasin program permits reduction of the first phase time requirement
from 5 to 3 years without incurring undue scientific and social risks.
The two-subbasin concept also improves the prospects of the transfer
of the technology from the test subbasins to the remaining 'candidate
areas within the Basin. The disadvantages of this option are that the
shorter time period allows less time for improvement of the existing
technology. Also, this option has the highest total c~st of the three
action options.

3. Six-year Program

The 2-year initial phase of this option would immediately apply existing
knowledge to design a 4-year dual subbasin demonstration phase. In

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