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<br />,..... <br />0) <br />c.::> <br />C.Jl <br /> <br />Indiscriminate use of streams by livestock on rangelands in Region VIII <br />has caused serious deterioration of the riparian habitat in many instances. <br />Cattle in particular prefer streamside areas for shade, more succulent <br />vegetation, and drinking water and tend to congregate ,in these areas. Heavy <br />streamside grazing results in breakdown of streambanks, cropping and trampling <br />of shrubs that shade the stream, and disturbance of stream bottoms. The <br />effects are streambank erosion, increased sedimentation, compaction of soil, <br />reduced density of vegetation and quality of forage, increased width and <br />decreased depth of channels, higher water temperatures, and direct deposition <br />of animal waste. This is especially damaging to aquatic ecosystems. <br /> <br />V. COMPCflENTS <br /> <br />1. Problem area identification <br /> <br />While grazing has been recognized as contributing to nonpoint source <br />pollution in Water Quality Management Plans for all states in Region VIII, the <br />degree of impact generally has not been determined nor have specific problem <br />areas been identified in the management plan for each state. All existing <br />legisl ation re~ires state water quality management agencies and federal land <br />management agencies to identify nonpoint source water pollution problems and <br />to deve lop and impl ement a water quality management pl an for each state. <br /> <br />Identification of specific rangeland areas causing water quality <br />degradation is the basic step in the development of remedial measures. These <br />may be a watershed, portions of a watershed, or stream segments. The <br />determination of principal cause, including natural conditions, and type or <br />types of contaminants are important also. Sediment and salt yields and <br />bacteria levels are most likely to be affected by livestock grazing. <br /> <br />Criteria that can be used include: <br /> <br />impairment of use of receiving waters for speCific purposes, e.g., <br />muni ci pal water suppli es, fisheri es. <br /> <br />failure of receiving waters to meet established water quality <br />standards. <br /> <br />sediment loading that is widely disproportionate to land area of the <br />drainage. <br /> <br />fragile areas having erodible soils and steep slopes (badlands) <br />where natural (geologic) erosion is occurring. <br /> <br />All states in Region VIII have water quality standards for dissolved <br />solids and all except Colorado have standards which limit suspended solids and <br />sediment or turbidity. Refer to individual state water quality standards for <br />specific parameters. <br /> <br />- 12 - <br />