WSP05347 - Laserfiche WebLink

Home Browse Search

rr01928 Development pressure in the uppermost reach of the San Juan River is currently anticipated through a proposal for a year round resort including a new ski area. The proposed development would be build in Mineral County, but the effects would be strongly felt in the Pagosa Springs area. Careful planning for both point and non-point pollution must take place to insure that the quality of the Upper San Juan River is maintained. Piedra River The Piedra River also originates on the Continental Divide and drains the sparsely populated strip of land immediately west of the San Juan River drainage area. The Piedra River empties into the Navajo Reservoir near the Colorado-New Mexico state line. Water Quality parameters follow basically the same pattern as in the San Juan River but do show slightly higher sediment and dissolved solids levels. Los Pinos River The Los Pinos River also originates on the Continental Divide and empties into Navajo Reservoir in New Mexico. The Los Pinos River also exhibits the same general water quality characteristics as the other major streams draining the southern slope of the San Juan Mountains. From the headwaters to Highway 160, including Vallecito Reservoir, it is a high quality trout fishery. Below Highway 160, dewatering for irrigation limits the aquatic life use, but the quality remains fairly good even though five small domestic dischargers are located on the stream. Animas River The Animas River rises in the extreme northern portion of the San Juan Basin in the San Juan and Uncompahgre Mountains. It flows almost directly south until it joins the San Juan River at Farmington, New Mexico. The Upper Animas River drains one of the most heavily mineralized and mining impacted areas in the state. Heavy metals and acid drainage destroy the biological integrity of some reaches in the upper tributary system. Portions of the river system are unacceptable for public water supplies. There is heavy metal contamination in the Animas River system above Silverton. Toxic levels of lead, manganese and copper are present. Acidity in this drainage also undermines water quality. Iron oxide,which is soluable under acid conditions, precipitaties onto the stream bottom as the water becomes more alkaline downstream. This precipitate destroys the populations of aquatic insects (benthos) upon which fish depend for food supply. Extremely low pH values are found in the Animas at Silverton and in Cement and Mineral Creeks above Silverton. The only creek in the Upper Animas River System, which supports a fair aquatic ecosystem is Cunningham Creek. Some benthic diversity and a number of trout are present in this stream. , -5- r