WSP08078

• File Number: 8277.500.10
• Description: Price and San Rafael Basin Unit - Colorado River Water Quality Improvement Program
• State: UT
• Basin: Colorado Mainstem
• Date: 12/1/1993
• Title: Planning Report / Final Environmental Impact Statement
• Water Supply Pro - Doc Type: EIS

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Summary

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The preferred plan in this document includes Reclamation's NED component-
off-farm irrigation systems and winter water improvement--eoupled with SCS'
NED component, unchanged except for the addition of 10,050 acres designated
for improved surface irrigation management. The onfarm and off-farm
irrigation improvement NED components are interdependent in terms of
economic and efficient operation.

ENVIRONMENTAL CONSEQUENCES

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A primary environmental effect of implementing the preferred plan would be its
contribution to maintaining acceptable salinity concentrations in the Colorado
River. The proposed project would reduce the annual salt load to the Colorado
River by 161,000 tons. Although total diversions would remain at the present
178,100 acre-feet per year, the amount of water delivered to farms would
increase by 5,930 acre-feet. Project-induced changes ;.n deep percolation would
result in net water depletions from the Colorado River.

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Construction of the off-farm component activities and facilities associated with
full implementation of the proposed project would temporarily disturb 457 acres
of upland salt-desert shrub, and alter or eliminate 8,330 acres of irrigation-
dependent wetlands. Uplands would be rehabilitated through recontouring and
seeding of native species. Reclamation would develop 330 acres of wetlands for
eventual transfer to the UDWR for management. This development would
replace in-kind total wetland losses projected for off-farm construction activities.
Replacement of wildlife habitat lost to onfarm activities would be on a
voluntary basis by individual landowners. Of onfarm changes impacting
irrigation-induced wetlands (5,260 acres), 77 percent occur in agricultural fields.
Of these wetlands, 97 percent are pasturelhayland or grass/sedge that are
routinely disturbed by mowing and grazing. Impacts to area wildlife would be
directly related to alterations in their habitats. Any recreational hunting lost
on private lands through habitat alterations as a result of the off-farm system
should be replaced by wildlife management areas.

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Fisheries resources within the overall project area are limited. The project
should improve water quality for aquatic species found in area streams. The
proposed project would alter local streamflows; the greatest change would be in
high-flow periods, with minor changes during low flows. There would be no
significant impact to trout populations or warm-water fisheries.

Two federally listed threatened and eight endangered species may inhabit the
proposed project area or be impacted by activities that occur within the area.
No terrestrial-listed plants or animals would be impacted, and the Service
concurs with this assessment. The proposed project would deplete annual flows
to the Colorado River by 25,310 acre-feet. The Service also concurs with
Reclamation's assessment that the proposed depletions may affect Colorado
River native endangered fishes, but has determined that any depletion of water
in the Colorado River is not likely to jeopardize the continued existence of the

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