Publications

Solute transport in streams and rivers is governed by a suite of hydrologic and geochemical processes. Knowledge of these processes is needed when assessing the fate of contaminants that are released into surface waters. The study of solute fate and transport often is aided by solute transport models that mathematically describe the underlying processes. This fact sheet describes a model...

No abstract available.

The hydrology and water quality of streams and lakes in the Guanella Pass area could be affected by the proposed reconstruction of the existing road over Guanella Pass between Georgetown and Grant, Colo. Data were collected during water years 1995 through 1997 (October 1, 1994, through September 30, 1997) that describe the preconstruction hydrology, water quality, sediment transport, and...

The Fountain Creek watershed, located in and along the eastern slope of the Front Range section of the southern Rocky Mountains, drains approximately 930 square miles of parts of Teller, El Paso, and Pueblo Counties in eastern Colorado. Streamflow in the watershed is dominated by spring snowmelt runoff and storm runoff during the summer monsoon season. Flooding during the 1990?s has...

Macroinvertebrate and algal community samples were collected during a 3-year period at sites located near Guanella Pass, Colorado, to provide baseline characterization data. Water-quality sampling and habitat evaluations were used to aid in the interpretation of the biological data. The study was part of an environmental investigation for a proposed roadway reconstruction project on...

No abstract available.

Snowpacks at two high-elevation (> 3,000 m) sampling sites near McPhee and Sanchez Reservoirs in southern Colorado were selected to collect representative samples of atmospheric deposition to the surrounding watersheds during winter 1999-2000. In February 2000, annual snowpacks at two sites were sampled to determine concentrations of nitrate and sulfate; concentrations of the trace...

The Upper Colorado River Basin study unit of the U.S. Geological Survey National Water-Quality Assessment Program consists of the Colorado River watershed upstream from near the Colorado-Utah State line. The basin is about equally divided between the Southern Rocky Mountains and the Colorado Plateau physiographic provinces. Data were collected at pairs of indicator sites for mining...

This report summarizes major findings about water quality in the upper Colorado River basin that emerged from an assessment conducted between 1996 and 1998 by the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) Program. Water quality is discussed in terms of local and regional issues and compared to conditions found in all 36 NAWQA study areas assessed to date...

We investigated the hydrologic, geochemical, and biogeochemical controls on stream chemical composition on the Green Lakes Valley and Andrews Creek watersheds using the alpine hydrochemical model (AHM). Both sites had comparable data sets from 1994 and 1996, including high‐resolution spatial data and high‐frequency time series of hydrology, geochemistry, and meteorology. The model of...

During 1999, a study was conducted by the U.S. Geological Survey (USGS) in cooperation with the Bureau of Reclamation to evaluate the effect of the Paradox Valley Unit on dissolved solids, sodium, and chloride in the Dolores River downstream from the Paradox Valley Unit. This report describes this evaluation and presents the results from this study. Daily mean flow and daily mean...

Forty-four river, stream, and drain sites in the Upper Colorado River Basin in Colorado were sampled during 1996?98 to determine the occurrence and distribution of pesticides in the basin. In a fixed-station study, 57 surface-water samples were collected from October 1996 through January 1998 at four sites. Each site was sampled approximately monthly for up to a year, with more frequent...