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10 in/yr in the lower altitudes of the western valleys.
<br />Temperature in the study unit ranges from -30 to
<br />110°F. The geology primarily consists of rocks of
<br />Precambrian age, stratified sedimentary rocks, and
<br />alluvial deposits. The topography in the eastern part
<br />of the study unit consists of north-northwest-trending
<br />mountains that range in altitude from 11,000 to more
<br />than 14,000 ft. The western part of the study unit
<br />generally consists of high plateaus with altitudes
<br />ranging from 5,500 to 8,500 ft, bordered by steep cliffs
<br />along valleys. The altitude of the valleys near the
<br />Colorado-Utah State line is about 4,300 ft.
<br />Predominant land uses in the UCOL study unit
<br />are mining, urbanization, and agriculture. Past and
<br />present mining activities have included the extraction
<br />of metals (copper, gold, lead, molybdenum, nickel,
<br />silver, vanadium, and zinc) and energy fuels (coal, gas,
<br />oil, and uranium). Urbanization is one of the smaller
<br />land uses in the mostly rural areas of the study unit. A
<br />number of urban areas are associated with growth
<br />resulting from the expansion of the ski industry and
<br />from energy development in the 1980's (Apodaca and
<br />others, 1996). Agriculture is the traditional land use in
<br />the Colorado Plateau and includes production of crops
<br />such as alfalfa, fruits, grains, hay, and vegetables.
<br />Hydrologic modifications occur throughout the
<br />study unit. The principal water use in the UCOL study
<br />unit is irrigation, which accounts for about 97 percent
<br />of the offstream-water use. The remaining 3 percent is
<br />accounted for by the following, in order of decreasing
<br />water use: livestock, domestic, power, industrial,
<br />commercial, and mining (Apodaca and others, 1996).
<br />Acknowledgments
<br />The authors thank April Kobayashi and Joyce
<br />Dickey, USGS, for their assistance in retrieval of
<br />information. The authors also thank the members of
<br />the UCOL NAWQA Liaison Committee for their
<br />cooperation in providing information and data about
<br />the basin. We would especially like to thank Richard
<br />Krueger from the U.S. Fish and Wildlife Service,
<br />Barbara Horn from the Colorado Division of Wildlife,
<br />and Lynn Cudlip from the National Park Service for
<br />providing information and data for this report.
<br />INVENTORY OF BIOLOGICAL AND
<br />CONTAMINANT INVESTIGATIONS OF
<br />STREAMS
<br />One-hundred-twenty-six biological and contam-
<br />inant investigations that relate to water quality in the
<br />UCOL study unit were grouped into six categories
<br />corresponding to the biological components of the
<br />NAWQA program: algae, macroinvertebrates, fish,
<br />habitat characterization, contaminants in organism
<br />tissue, and contaminants in bed sediments. informa-
<br />tion about each biological and contaminant component
<br />is essential to understand water quality in the study
<br />unit. Biological and contaminant investigations in the
<br />study unit are listed by the category of investigation
<br />and their locations in the two physiographic provinces
<br />(table 1). Information about the predominant land use,
<br />water-chemistry data, and general description and
<br />locations of biological or contaminant investigations
<br />also are listed in table 1. Studies that had land-use
<br />information from sampling sites on streams that were
<br />unaffected by human activity or conducted to establish
<br />baseline data were defined as background. Studies
<br />that had sampling sites in more than one land-use
<br />category (for example, in mining, urban, and agricul-
<br />tural land uses) were defined as mixed land-use
<br />studies. Studies that had stream reaches directly
<br />affected by various water uses or by hydrologic
<br />modification, such as dams and canals, also were
<br />categorized in the land-use column (Hyd) in table 1.
<br />Several of the studies were not applicable (NA) to a
<br />predominant land use, but contained pertinent,
<br />generalized information about biological characteris-
<br />tics of the study unit. If an investigation had water-
<br />chemistry data collected in addition to the biological
<br />and contaminant data, an X was placed in the "Water-
<br />chemistry data" column in table 1. This information
<br />was provided because integration of biologica! and
<br />water-chemistry data can be a useful tool in water-
<br />qualityanalysis and because integrated information is
<br />a major component of the NAWQA program.
<br />An important aspect of the NAWQA program is
<br />to understand the effects of land use on water quality.
<br />The objectives of the studies listed in table 1 might not
<br />relate to the effects of land use on water quality; but,
<br />the inventory of these studies according to land use
<br />can help in the overall water-quality sampling design
<br />of the UCOL study unit and in filling in some of the
<br />gaps in biological data. Data collected during many of
<br />the investigations were from both physiographic
<br />Summary of Biological and Con#aminant Investigations Related to Stream Water (iualtty and Environmental Setting in the
<br />Upper Colorado River Basin, 1938-95
<br />
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