Publications

The development of indicators to assess relative freshwater condition is critical for management and conservation. Predictive modeling can enhance the utility of indicators by providing estimates of condition for unsurveyed locations. Such approaches grant understanding of where “good” and “poor” conditions occur and provide insight into landscape contexts supporting such conditions. However, as a

Concerns related to perfluoroalkyl and polyfluoroalkyl substances (PFAS) in sources of drinking water and in natural and engineered environments have captured national attention over the last few decades. This report provides an overview of the science gaps that exist in the fields of study related to PFAS that are relevant to the U.S. Geological Survey mission and identifies opportunities where t

Paleoflood studies are an effective means of providing specific information on the recurrence and magnitude of rare and large floods. Such information can be combined with systematic flood measurements to better assess the frequency of large floods. Paleoflood data also provide valuable information about the linkages among climate, land use, flood-hazard assessments, and channel morphology. This d

Estuaries, at the nexus of rivers and the ocean, are depositional areas that respond to changes in streamflow, tides, sea level, and inputs of sediment from marine and watershed sources. Understanding changes in bed elevations, deposited and eroded sediment, and water depth throughout estuaries is relevant for understanding their present-day status and long-term evolution, identifying potential ha

Surface-water quality can change in response to climate perturbations, such as changes in the frequency of heavy precipitation or droughts, through direct effects, such as dilution and concentration, and through physical processes, such as bank scour. Water quality might also change through indirect mechanisms, such as changing water demand or changes in runoff interaction with organic matter on t

Saltwater intrusion and declining water levels have been a water-supply problem in Cape May County, New Jersey, for decades. Cape May County is surrounded by saltwater on three sides. Several communities in the county have only one aquifer from which freshwater withdrawals can be made, and that sole source is threatened by saltwater intrusion and (or) substantial declines in water levels caused by

We present a geostatistics-based stochastic salinity estimation framework for the Montebello Oil Field that capitalizes on available total dissolved solids (TDS) data from groundwater samples as well as electrical resistivity (ER) data from borehole logging. Data from TDS samples (n = 4924) was coded into an indicator framework based on falling below four selected thresholds (500, 1000, 3000, and

From October 1, 1999, through September 30, 2009, water-quality samples were collected, and discharge was measured at 13 streamgages within the Catskill and Delaware watersheds of the New York City water supply system. The Catskill and Delaware watersheds supply about 90 percent of the water needed by 9 million customers. On average, 59 water-quality samples were collected at each station during e

Responsible stewardship of native fish populations and riparian plants in the Meduxnekeag River watershed in northeastern Maine is a high priority for the Houlton Band of Maliseet Indians. Understanding the potential changes in hydrology and water temperature as a result of climate change is important to this priority for evaluating future habitat conditions in the watershed. This report, prepared

The retreat of alpine glaciers since the mid-19th century has triggered rapid landscape adjustments in many headwater basins. However, the degree to which decadal-scale glacier retreat is associated with systematic or substantial changes in overall coarse sediment export, with the potential to impact downstream river dynamics, remains poorly understood. Here, we use repeat topographic surveys to a

The autumn and winter flood season of western Washington coincides with the incubation period of many Pacific salmon (Onchorhynchus spp.) populations. During this period, salmon embryos incubating within gravel nests called “redds” are vulnerable to mobilization of surrounding sediment during floods. As overlying sediment is transported downstream, the vertical position of the streambed can be low

Leavenworth Creek, a tributary of South Clear Creek and Clear Creek near Georgetown, Colorado, contains copper, lead, and zinc at concentrations close to or in excess of aquatic-life standards. In the summer of 2012, the U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service and the Colorado Division of Reclamation, Mining and Safety, conducted monitoring to