Reports

The U.S. Geological Survey (USGS) has operated streamflow-gaging stations in 1,053 watersheds in the Upper Colorado River Basin (UCRB) since 1894. Currently, 223 of these streamgages are active. This report presents selected watershed characteristics for 10,338 watersheds in the UCRB. These watersheds are compared to the watersheds upstream of USGS streamgages to assess how well the USGS

Since late 1993, Metro Wastewater Reclamation District of Denver (Metro District), a large wastewater treatment plant in Denver, Colo., has applied Grade I, Class B biosolids to about 52,000 acres of nonirrigated farmland and rangeland near Deer Trail, Colo., U.S.A. In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring groundwater at part of...

Studies of the natural environment in the Grants Mineral Belt in northwestern New Mexico have been conducted since the 1930s; however, few such investigations predate uranium mining and milling operations, which began in the early 1950s. This report provides an annotated bibliography of reports that describe the hydrology and geochemistry of groundwaters and surface waters and the...

Estimates of annual peak-streamflow frequency are needed for flood-plain management, assessment of flood risk, and design of structures, such as roads, bridges, culverts, dams, and levees. Regional regression equations have been developed and are used extensively to estimate annual peak-streamflow frequency for ungaged sites in natural (unregulated and rural or nonurbanized) watersheds...

During and after the planned incremental removal of two large, century-old concrete dams between 2011 and 2014, the sediment-transport regime in the lower Elwha River of western Washington will initially spike above background levels and then return to pre-dam conditions some years after complete dam removal. Measurements indicate the upper reaches of the steep-gradient Elwha River...

A watershed model using Hydrologic Simulation Program-FORTRAN (HSPF) was developed for the urbanized Chino Basin in southern California to simulate the transport of pathogen indicator bacteria, evaluate the flow-component and land-use contributions to bacteria contamination and water-quality degradation throughout the basin, and develop a better understanding of the potential effects of...

Groundwater use from shallow, high-capacity wells is expected to increase across southeastern Wisconsin in the next decade (2010-2020), owing to residential and business growth and the need for shallow water to be blended with deeper water of lesser quality, containing, for example, excessive levels of radium. However, this increased pumping has the potential to affect surface-water...

Spatially Referenced Regression On Watershed attributes (SPARROW) models were developed to provide spatially explicit information on local and regional total nitrogen and total phosphorus sources and transport in the Missouri River Basin. Model results provide estimates of the relative contributions from various nutrient sources and delivery factors. The models also describe instream...

The Invasive Species Science Branch of the Fort Collins Science Center provides research and technical assistance relating to management concerns for invasive species, including understanding how these species are introduced, identifying areas vulnerable to invasion, forecasting invasions, and developing control methods. This fact sheet considers the invasive plant species tamarisk...

Pilot points have been used in geophysics and hydrogeology for at least 30 years as a means to bridge the gap between estimating a parameter value in every cell of a model and subdividing models into a small number of homogeneous zones. Pilot points serve as surrogate parameters at which values are estimated in the inverse-modeling process, and their values are interpolated onto the...

No abstract available.

The removal of two long-standing dams on the Elwha River in Washington State will initiate a suite of biological and physical changes to the estuary at the river mouth. Estuaries represent a transition between freshwater and saltwater, have unique assemblages of plants and animals, and are a critical habitat for some salmon species as they migrate to the ocean. This chapter summarizes a...