Composite land use impacts on water quality on a diversely developed watershed

Abstract

The purpose of this study was to assess the composite land use effects on water quality on a diversely developed tributary to the South Platte River in the Colorado Front Range. Data were collected over a two-year period to assess impacts of mountain home development, grazing and lake-based recreation on suspended solids, specific conductance, total dissolved solids, nitrate, chloride, fecal coliform and fecal streptococcal bacteria. Four specific treatment areas were evaluated for both their local and composite impact on the selected constituents. Treatments included grazing, road-fill encroachment, lake-based recreation and extended primary sewage treatment. Additional sites were selected to characterize the water quality of strategic locations in the watershed. Cluster analysis was employed to aid the interpretation of the composite land use effects on water quality. Findings at the four treatment sites showed significant increases in fecal streptococcal bacteria densities at the grazing sites, considerable suspended solids delivered to the creek during runoff events at the road sites, no substantial effect on stream water quality from lake-based recreation and significant increases in suspended solids, total dissolved solids, specific conductance, nitrate and chloride at the sewage lagoon treatment sites. Differences in the composite land use effects on water quality could only be discerned by comparing the water quality of the tributaries to the main stream. Water quality differences related to land use were found with suspended solids, nitrates, chlorides, fecal coliform and fecal streptococcal bacteria. No substantial differences in water quality were found between the three clusters on the Trout Creek main stem. General water quality of the watershed was good and no serious water quality problems were indicated.

Citation

Gowen, Peter J. 1981. Composite land use impacts on water quality on a diversely developed watershed. Fort Collins, CO: Colorado State University. 112 p. Thesis.