Water-Quality Assessment of Wolford Mountain Reservoir on Muddy Creek near Kremmling, Colorado

Science Center Objects

In March 1985 the U.S. Geological Survey (USGS), in cooperation with the Colorado River Water Conservation District (CRWCD), began a monitoring program on Muddy Creek in anticipation of the construction of a water storage project. A site upstream of the proposed reservoir (Muddy Creek above Antelope Creek, 09041090), and a downstream site (Muddy Creek at Kremmling, 09041500) were chosen to characterize pre-impoundment conditions. Wolford Mountain Reservoir was constructed during the period 1992-94. Filling of the reservoir began in 1995. Adjustments were made to the monitoring program in 1995 to focus on water quality in the reservoir and the outflow. Data collected included continuous measurement of streamflow, water temperature, specific conductance and dissolved oxygen (below dam after construction only), and periodic samples collected approximately monthly were analyzed for major ions, nutrients, and suspended sediment. Trace element samples were collected approximately twice per year. Three reservoir sampling locations were established with sampling occuring approximately 4 times per year at the surface and just above the bottom at mid-lake and near the dam, and at a mid-water-column depth near the inflow to the reservoir. In addition to depth profiles of water temperature, specific conductance, pH, and dissolved oxygen, constituents sampled at the surface and near the bottom of the reservoir include major ions, nutrients, trace elements, and chlorophyll-a.

When water storage is created on a stream, normal discharge patterns downstream can be altered, quality of the water can change, and a new hydrologic environment is created in the reservoir. An assessment of these changes in newly constructed reservoirs can improve the prediction and understanding of the effects of new reservoirs on streams and the quality of water in reservoirs. Description and analysis of the data is necessary to provide information and a return on the investment of years of of data collection by the USGS and our cooperators.



    1. To characterize and compare the preconstruction, construction, and postconstruction streamflow and water-quality characteristics of Muddy Creek
    2. To describe limnological and water-quality characteristics of Wolford Mountain Reservoir (1995-2000)
    3. To compare water-quality data to Colorado water-quality standards and guidelines.

    USGS Water-Data Sites Referenced: