Publications

Concern about water-quality issues related to wildfires in Colorado has intensified because of the wildfires that occurred in Colorado during the summer of 2002. In 2003, the U.S. Geological Survey (USGS) conducted water-quality sampling of burned and unburned watersheds in the areas affected by the Hayman, Hinman, and Missionary Ridge wildfires to provide information to scientists, watershed mana

Introduction: Population growth and changes in land-use practices have the potential to affect water quality and quantity in the upper Gunnison River basin. In 1995, the U.S. Geological Survey (USGS), in cooperation with local sponsors, City of Gunnison, Colorado River Water Conservation District, Crested Butte South Metropolitan District, Gunnison County, Mount Crested Butte Water and Sanitat

One of the important types of information needed to characterize water quality in streams affected by historical mining is the seasonal pattern of toxic trace-metal concentrations and loads. Seasonal patterns in water quality are estimated in this report using a technique called water-quality profiling. Water-quality profiling allows land managers and scientists to assess priority areas to be targ

Discharge of brine with an average dissolved-solids concentration of about 256,000 milligrams per liter from alluvium in Paradox Valley, a collapsed salt anticline, substantially increases the dissolved-solids load of the Dolores River. In 1996, the Bureau of Reclamation began operation of the Paradox Valley Unit, a series of brine-withdrawal wells completed in alluvium along the Dolores River and

Reddish brown flocs form along the edge of the Coeur d'Alene River when porewater drains into river water during the annual lowering of water level in the basin. The precipitates are efficient scavengers of dissolved elements and have characteristics that may make metals associated with them bioavailable. This work characterizes the geochemistry of the porewater and models the formation and compos

A field study at Coeur d'Alene Lake, Idaho, USA, was conducted between October 1998 and August 2001 to examine the potential importance of sediment-water interactions on contaminant transport and to provide the first direct measurements of the benthic flux of dissolved solutes of environmental concern in this lake. Because of potential ecological effects, dissolved zinc and orthophosphate were the

Long-term measurements (1983-2001) of nutrients and seston in Emerald Lake (Sierra Nevada, California) have revealed ecologically significant patterns. Nitrate, both during spring runoff and during growing seasons, declined from 1983 through 1995. Declining snowmelt nitrate was caused primarily by changes in snow regime induced by the 1987-1992 drought: years with shallow, early melting snowpacks

Ground water occurrence, movement, and its contribution to streamflow were investigated in Loch Vale, an alpine catchment in the Front Range of the Colorado Rocky Mountains. Hydrogeomorphologic mapping, seismic refraction measurements, and porosity and permeability estimates indicate that talus slopes are the primary ground water reservoir, with a maximum storage capacity that is equal to, or grea

High-elevation lakes in the western United States are sensitive to atmospheric deposition of sulfur and nitrogen due to fast hydrologic flushing rates, short growing seasons, an abundance of exposed bedrock, and a lack of well-developed soils. This sensitivity is reflected in the dilute chemistry of the lakes, which was documented in the U.S. Environmental Protection Agency's Western Lake Survey o

On October 25, 1997, in and around the Routt National Forest and the Mount Zirkel Wilderness Area, a winter snowstorm occurred in conjunction with heavy winds that resulted in the destruction of thousands of acres of old-growth tree stands. The U.S. Geological Survey, in cooperation with the U.S. Forest Service, collected water-quality data at five sites in the North Fork Elk River watershed where

The U.S. Geological Survey, in an ongoing cooperative monitoring program with the Northern Colorado Water Conservancy District, Bureau of Reclamation, and City of Fort Collins, has collected water-quality data in north-central Colorado since 1969 in reservoirs and conveyances, such as canals and tunnels, related to the Colorado–Big Thompson Project, a water-storage, collection, and distribution sy

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