To determine the effect of population growth on streamwater quality in the Fraser River Basin, the U.S. Geological Survey did a study in cooperation with the Grand County Commissioners and the East Grand County Water Quality Board. During water years 1991 through 2000, the study determined that concentrations of un-ionized ammonia and nitrite plus nitrate in the streamwater of the basin are within Colorado State streamwater?quality standards. The study also found that concentrations of chloride are largest at the headwaters and decrease downstream; however, chloride loading in the stream has the opposite relation. Most nutrient loading to the Fraser River happens January through May. Concentrations of ammonia at Fraser River downstream from Vasquez Creek at Winter Park had a downward trend through the period of the study. Nitrite plus nitrate had upward and downward trends at different sites and over different time spans. Orthophosphorus concentrations had upward trends at two sites. In general, the streamwater quality in the Fraser River Basin is good and is not out of compliance with State standards.
Additional publication details
USGS Numbered Series
Streamwater quality at selected sites in the Fraser River basin, Grand County, Colorado, water years 1991-2000