Detailed evaluation of salinity trends at selected salinity control projects.
To delineate salinity reductions caused by salinity control projects from other factors that may have affected salinity trends at selected projects.
Need and Benefit
Previous studies have shown downward salinity trends at sites below salinity control projects. However, there have also been downward salinity trends at sites not affected by salinity control. The question raised is what are the actual salt reductions resulting from salinity control projects as opposed to salt reductions caused by other factors within the Colorado River Basin. Also, other changes in the basin might increase salinity, and these need to be examined as well. Determining if the salinity control projects Reclamation has been involved with and funded are performing as expected will enhance the Salinity Control Program as authorized by Public Law 84-485 and 87-483.
With the charge from Congress through the Secretary of the Interior for Reclamation to study and report on the salinity of the Colorado River Basin, we should determine the effectiveness of the projects that have been established. The results of this research project will help with the selection of new projects by determining the effectiveness of previous selected projects and if we are having any effect on salinity when compaired with natural variations.
Based on results from Vaill and Butler (1999) and other studies, four salinity control projects would be evaluated in detail: Big Sandy Unit, Uinta Basin Unit, Lower Gunnison Unit, and Grand Valley Unit. Salinity trends would be tested using parametric and nonparametric statistical methods. In addition to salt concentrations and loads, other water quality parameters would be evaluated. At the four project areas, other factors not related to salinity control, such as land use or water use changes, would be examined to determine if other factors could have affected salt trends in the basin or downstream from the project.
Contact the Principal Investigator for information about these documents.