Identifying Changes in Background Water-Quality Conditions, Arkansas River and Fountain Creek, near Pueblo, Colorado

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Demands for water are projected to increase in the Lower Arkansas River Basin as the population continues to grow. Strategies to meet those demands include continued operation of the Fryingpan-Arkansas Project water, enlargement of Pueblo and Turquoise Reservoirs, and various conservation measures; the overall strategy is defined in the Preferred Storage Options Plan (see the Southeastern Colorado Water Conservancy District site, https://secwcd.org). Water-quality impacts to the river are possible as these strategies are implemented.

In 2002, a basic water-quality monitoring program was established in the Lower Arkansas River Basin to collect additional data needed to support the PSOP. Because no known methods were available to determine what effects future changes in operations will have on water quality, the U.S. Geological Survey, in cooperation with the Southeastern Colorado Water Activity Enterprise, began a study in 2002 to develop methods that could identify if future water-quality conditions have changed significantly from background (preexisting) water-quality conditions.

Methods have been developed to identify changes in background water-quality conditions using dissolved-solids concentrations and dissolved-solids loads as indicators at selected sites in the Arkansas River and Fountain Creek near Pueblo, Colorado.  Daily dissolved-solids concentrations were estimated from daily specific-conductance values. The information is documented in the published report U.S. Geological Survey Scientific Investigations Report 2004-5024 and comparison plots presented on the internet can be used as a real-time decision-support tool.  Estimated real-time dissolved-solids concentrations and loads in the study areas may be considered as surrogates for current water-quality conditions and the information used to determine whether future water-quality conditions differ from current water-quality conditions.

Double Mass Curves updated through 2018.

To generate comparison plots of water-quality conditions, please click the "Data and Tools" tab above then select the model link.