WSP03802

• File Number: 8274.200
• Description: Colorado River Basin Salinity Control - General Basinwide Salinity Issues
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 9/11/1980
• Title: Baseline Values
• Water Supply Pro - Doc Type: Report/Study

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BASELINE VALUES

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Baseline values are a relationship between salt load and flow
at selected sites. There is no intent to make baseline values standards

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nor are they to be considered or interpreted as standards for salinity.

The 1975 Forum report called for the development of baseline

values for monitoring points on the mainstem and major tributaries

as part of the process of identifying and evaluating changes in

river salinity.

The baseline values will be used to assess the

effects of development, salinity control measures and/or other
changes in the area upstream of the baseline station. They may be
used to adjust the parameters used in the river salt routing models.

Because salinity concentrations at any point are influenced

by a number of factors, it has been concluded that baseline values
would be best represented by a range of values rather than a single
value. This range is represented by a broad band superimposed on
a best-fit curve of the relationship between annual salt load and

annual flow at a given station.

The initial baseline values are

based on historical data for the period 1941-1972, adjusted to
1972 levels of development.
If, in the future, the value expressing the relationship
between salt load and flow at a selected site falls within the band

for that site, it may be assumed that no significant changes in the

relationship have taken place.

However, if the points continue to

fall outside the band without this being the result of known actions,

an investigation will be made to determine the cause of the change.