The Blue River drains approximately 680 square miles west of the
Continental Divide in central Colorado before flowing northward into
the Colorado River near Kremmling, Colorado. The Blue River watershed
(BRW) is almost entirely located in Summit County and includes the
towns of Breckenridge, Dillon, Frisco, Montezuma, and Silverthorne.
Dillon Reservoir and Green Mountain Reservoir are major water storage
facilities in the watershed. The BRW upstream from Dillon Reservoir is
in the Colorado Mineral Belt, a zone of economically significant
metals deposits. Hard-rock mining was the major industry in this area
from 1859 through the first half of the 1900s. With the development of
ski areas beginning in 1945 and the construction of Interstate-70,
Summit County has become a major four-season resort destination. Ski
resorts such as Arapahoe Basin, Breckenridge, Copper Mountain, and
Keystone have brought rapid population growth and increased tourism
and development to the area.
Mineralized bedrock, historical mining activities, and more recent
urban development related to population growth, tourism, second-home
development, and recreation have affected water quality and aquatic
biota in the BRW. High concentrations of trace elements can occur
naturally from the weathering on mineralized rock and acid mine
drainage. Septic and wastewater systems and runoff from developed
lands can affect nutrient concentrations in water bodies, and highway
sanding in winter can increase sediment loading to nearby streams.
With these considerations, the USGS, in cooperation with the Summit
Water Quality Committee, is conducting a study to compile and assess
water quality in the BLW. Specific objectives of the study are to:
Develop a water-quality database (Data Repository) from available
data in the BRW.
Characterize available water-quality data for the watershed,
Analyze historical data and describe the spatial and seasonal
distribution and temporal trends of water-quality data, and
Identify, describe, and explain, where possible, the natural and
human factors that could be affecting observed water-quality conditions.
An interpretive report of water quality in the BRW will be
published by the USGS.
The Data Repository is constructed to allow users to retrieve
water-quality data for the BLW through a web browser. Included are
interactive maps for browsing and selecting site locations, and menus
for choosing sites, samples, agencies, and water-quality parameters to
be used in the data retrieval.
