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Revision February 1982 snowmelt source with a low concentration of total suspended solids except during the snowmelt season. Total suspended solids concentrations average 100.8 mg/1 with a high of 862 mg/1 occurring June 6, 1978. Dissolved metals concentrations are low throughout the year, while total metals con- centrations are directly related to total suspended solids concentrations due to adsorption on the colloids. Therefore, the total metals con- centrations are high during the snowmelt season and low the rest of the year. Nutrient concentrations are low. The North Fork of the Gunnison River has an average annual discharge of 427 cfs with a maximum recorded peak discharge of 786 cfs (June 4, 1957) at the USGS gaging station about a mile downstream of the permit area (Exhibit 2.04.5-A, Appendix XIII). The same station recorded a minimum discharge of 17 cfs in 1951. The yearly hydrograph is snowmelt regulated. The highest discharge is recorded in May due to snowmelt with a gradual decline through the summer and fall months. A minimum is reached in January and February. From old USGS records on Muddy Creek and Anthracite Creek it appears that Anthracite Creek contributes about two-thirds of the flow in the North Fork of the Gunnison River. Water quality of the North Fork near the permit area has been sampled at eight stations by the USGS, WSC, and Beak Consultants Incorporated under contract to WSC (Appendix XIV and op. 2.05-59, 60, 61, Exhibit 2.04.5-A and ~. The water is an alkaline, soft, calcium-bicarbonate-sulfate type with an average total dissolved solids concentration of 101.1 mg/l. The water is cold due to the snowmelt source with a low concentration of total suspended solids except during the snowmelt season. Total suspended solids concentrations average 24.2 mg/1 with a high of 105 mg/1 on April 26, 1977. 2.04-28