WSPC02982

• File Number: 8200.700
• Description: Colorado River Basin General Publications - Augmentation-Weather Modification
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 2/1/1977
• Author: DOI-BOR
• Title: Status Report - Sierra Cooperative Pilot Project Design Program - With Excerpts from Weather Modification Design Study for Streamflow Augmentation in the Northern Sierra Nevada
• Water Supply Pro - Doc Type: Report/Study

002hB2

SECTION I

THE INITIAL DESIGN

The initial step in developing a site-specific design for the
SCpp was the award of a design study contract to MBA. This
investigation and analysis marked the turning point from the over-
view of the meteorological conditions of the Sierra Nevada to
selection of a particular watershed in which research operations,
data collection, and evaluation could be accomplished with an
effective scientific procedure.

The first major recommendation of Phase I of the MBA study was to
concentrate the activities of the SCPP in the American River Basin,
where similarities to the CENSARE7 program and the availability
of a meteorological data base produce the highest probability of
achieving scientifically significant results. Apparent differences
in the physical characteristics between the American and Feather
River watersheds and associated differences in the precipitation
producing meteorological processes led to the conclusion that
different program designs probably are necessary for each region.
Consequently, additional scientific studies were recommended in
the Feather River Basin prior to extension of the pilot project to
that region. In addition, a l-year preliminary observation/data
acquisition program for the American River Basin was recommended
to precede the establishment of the pilot project there. The
purpose of this recommendation was to confirm the transferability
of CENSARE findings to the American River Basin, to assess the
proper role and operating locations for weather radar and other
instrumentation, and to provide for a study of the seeding material
trajectories.

The feasibility of transferring the technology developed from the
American River Basin to the surrounding Sierra Nevada basins, which
may have a greater augmentation potential, will be an important
consideration of the SCPP studies. Additional investigations in
the Feather River Basin will further this goal.

Figure 1 shows the recommended SCPP area. It is defined by the
ridge crest of the American River watershed on the north, east,
and south sides, and by a line connecting the intersections of
the crest lines of each subbasin with the 1220 m (4000 ft) elevation
contour. (Elevation 1830 m (6000 ft) is also shown. Primary
increases in snowpack are expected above this contour.)

7. CENtral SierrA REsearch Project (CENSARE) A cloud seeding
project conducted by Atmospheric Water Resources Research, California
State University, Fresno Foundation from 1968 to 1973 for the
Division of Atmospheric Water Resources Management, Bureau of Reclamation.

7