WSP03721

• File Number: 8276.300
• Description: Lower Gunnison Basin Unit - Colorado River Basin Salinity Control Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 4
• Date: 12/1/1989
• Title: Colorado River Water Quality Improvement Program Lower Gunnison Basin Unit North Fork Area Preliminary Findings Report December 1989
• Water Supply Pro - Doc Type: Report/Study

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CHAPTER II

PLAN FORMULATION

Plan formulation for the North Fork study was directed at identifying the
salt loading problem in the area, formulating alternatives to reduce salt
loading, and evaluating those alternatives.

Criteria and Standards for plans

Problems and opportunities in the area were identified, and the
capability of available resources to meet these problems and opportunities was
evaluated. This evaluation of needs and resources provided the basis for
developing alternative salinity control plans.

Alternative plans were formulated and evaluated to a sufficient level of
detail to determine if they warranted further study. Cost effectiveness, the
annual cost of preventing 1 ton of salt from entering the Colorado River, was
the criteria used to make this determination for salinity sources for which
control options were technically possible.

Identification of Salinity Sources

The results of water quality sampling programs conducted by Reclamation,
the Soil Conservation Service (SCS), and United States Geological SUrvey ,
(USGS) were used to identify subareas within the overall study area which were
major salinity contributors. These subareas, described subsequently, are
Tongue Creek, Oak Creek, Special Study Area, North Delta, Colona Area, and the
Geyser Well.

Two electrical conductivity (Ee) profile measurements of the North Fork
and Gunnison Rivers were conducted to locate major salt contributors not
identified by the water quality sampling stations and grab sample surveys.

The first EC river profile was conducted from June 26 - July lO, 1986; a
second EC profile was conducted October 6-10, 1986, to provide additional data
not available from the preliminary river profile, confirm the earlier
findings, and to gain new insights by taking EC measurements during a lower
flow regime. The results of the EC profile surveys have been documented on
supporting material.

The EC profiles did not identify additional major salinity sources.
Instead, the profiles confirmed the diffuse and gradual nature of the salinity
accumulation along the river and reinforced the results of the individual
component analyses discussed subsequently.

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