Publications

In 2017, the U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board (CWCB), studied floods in the historic record to produce a library of flood-inundation maps for the South Platte River at Fort Morgan, Colorado. Digital flood-inundation maps for a 4.5-mile (7.2-kilometers) reach of the South Platte River at Fort Morgan from Morgan County Road 16 to...

Effective management and protection of water resources relies upon understanding how water-quality conditions are changing over time. Water-quality trends for ammonia, chloride, nitrate, sulfate, total dissolved solids (TDS), total nitrogen (TN) and total phosphorus (TP) were assessed at 762 sites located in the conterminous United States between 2002 and 2012. Annual mean concentrations...

Contaminants diffusing from fractures into the immobile porosity of the rock matrix are subject to prolonged residence times. Organic contaminants can adsorb onto organic carbonaceous materials in the matrix extending contaminant retention. An investigation of spatial variability of the fraction of organic carbon (foc) is conducted on samples of rock core from seven closely spaced...

As part of a collaborative study designed to better understand water-quality conditions in the Sacramento River, surface-water samples were collected from the lower Sacramento River and five of its tributaries and then analyzed by the U.S. Geological Survey for a suite of 162 current-use pesticides and pesticide degradates. Samples were collected in May and October 2016 at 16 sites on...

In 2017, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, drilled and constructed borehole TAN-2312 for stratigraphic framework analyses and long-term groundwater monitoring of the eastern Snake River Plain aquifer at the Idaho National Laboratory in southeast Idaho. The location of borehole TAN-2312 was selected because it was downgradient from TAN and...

Downstream flow in rivers is repeatedly delayed by hydrologic exchange with off‐channel storage zones where biogeochemical processing occurs. We present a dimensionless metric that quantifies river connectivity as the balance between downstream flow and the exchange of water with the bed, banks, and floodplains. The degree of connectivity directly influences downstream water quality —...

Lead mining first began in the Big River watershed during the 1700s. Lead was the primary metal mined throughout most of the 1700s and early 1800s and it continued to be mined until the mid-1900s. Barite mining began in the middle part of the watershed in the mid- to late 1800s. Although considerable attention has been given to concentrations of miningrelated trace elements (mostly...

This report summarizes analyses of middle Verde River watershed environmental flows detailed in U.S. Geological Survey Scientific Investigations Report 2017-5100, “Preliminary synthesis and assessment of environmental flows in the middle Verde River watershed, Arizona," by N.V. Paretti, A.M.D. Brasher, S.L. Pearlstein, D.M. Skow, B. Gungle, and B.D. Garner.

Chemical and isotopic data for water co-extracted with hydrocarbons in oil and gas fields are commonly used to examine the source of the formation water and possible impacts on groundwater in areas of oil and gas development. Understanding the geochemical variability of oil-field water could help to evaluate its origin and delineate possible contamination of shallow aquifers in cases...

Floods in the Mississippi basin can have large negative societal, natural, and economic impacts. Understanding the drivers of floods, now and in the future, is relevant for risk management and infrastructure-planning purposes. We investigate the drivers of 100-yr-return lower Mississippi River floods using a global coupled climate model with an integrated surface water module. The model...

Nitrapyrin is a nitrification inhibitor that is co-applied with nitrogen fertilizer in agroecosystems. There is limited information on the fate of nitrapyrin after it is applied to agricultural soils. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its metabolite 6‑chloropicolinic acid (6...

The Allegheny Portage Railroad National Historic Site (ALPO) in Blair and Cambria Counties, Pennsylvania, protects historic features of the first railroad portage over the Allegheny Front and the first railroad tunnel in the United States. This report, which was completed by the U.S. Geological Survey in cooperation with the National Park Service, summarizes water resources in the...