WSPC04468

• File Number: 8272
• Description: Colorado River - Colorado River Basin Salinity Control Program - CRBSCP
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1989
• Author: DOI-BOR
• Title: Colorado River Water Quality Improvement Program - Preliminary Findings Report - Uinta Basin Unit - Phase II
• Water Supply Pro - Doc Type: Report/Study

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FINDINGS

Description of Phase I

Since the passage of the Colorado River Basin Salinity Control Act
(Public Law 93-320), Reclamation's Utah Projects Office in Provo has
completed planning investigations for phase I of the Uinta Basin Unit
salinity study. A planning report/draft environmental impact
statement was filed with the Environmental Protection Agency on
April 25, 1986. Construction on the unit has been postponed
indefinitely.

During the phase I study, Reclamation investigated a wide range of
methods for reducing the salt loading from the area. These included
canal and lateral lining to reduce seepage, deep-well injection of
saline drain water, evaporation ponds, desalting plants, industrial
use of saline water, and the retirement of high-salt-contributing
agricultural lands.

The canal and lateral-lining alternative was formulated by dividing
the lower-lying reaches of the unit areas into 17 separate increments
(subareas), each consisting of a group of canals and laterals in
reasonably close proximity to each other, which could be lined
independently of other increments. Each subarea is a logical and
practical part of a specific delivery system such as an entire lateral
system and/or a major unbroken segment of canal. The subareas were
also defined hydrologically so that inflow, outflow, and salt loading
could be determined for each area. The areas included in the phase I
study were those that have the greatest salt loading potential based
primarily on the location of marine shales and shale derived soils,
ground water quality and measured salt loading below the areas.
Generally, the higher gravelly benches and the Upper Lake Fork area
were excluded from the phase I study because of the relatively low
salt loading.

Approximately 140 of the 240 miles of canals and laterals within the
17 subareas were identified for potential lining. The canals vary in
capacity from 5 to 480 ft'/s and in length from 1.5 to 18 miles. The
laterals vary from 3 to 35 ft'/s in capacity and from 2.3 to
11.7 miles in length.

only six of the 17 subareas had canals and laterals which passed all
four plan-formulation tests of viability (including cost-
effectiveness) and were thus included in the recommended plan of
development. These six subareas are: (1) Zimmerman Wash, (2) pleasant
valley, (3) Gray Mountain, (4) Pahcease, (5) South Fork Dry Gulch, and
(6) Purdy-Midview. The recommended plan for phase I includes concrete
lining 43.9 miles of canals and 11.6 miles of laterals, involving nine
canals in the six subareas. Nearly 50 percent of the canals and
laterals to be lined have capacities of 15 ft'/s or less. Only about
25 percent are in the 60 to 360 ft'/s range, and these sections are
all part of either the Gray Mountain Canal in the Gray Mountain
subarea or the upper Pleasant Valley Canal in the Pleasant Valley
subarea.

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