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At least 1,243 records · Page 69Linked to original sources
USGS1993

Hydrology, vegetation, and soils of four north Florida River flood plains with an evaluation of state and federal wetland determinations

A study of hydrologic conditions, vegetation, and soils was made in wetland forests of four north Florida streams from 1987 to 1990. The study was conducted by the U.S. Geological Survey in cooperation with the Florida Department of Environmental Regulation to support State and Federal efforts to improve wetland delineation methodology in flood plains. Plant communities and soils were described and related to topographic position and long-term hydrologic conditions at 10 study plots located on 4 streams. Detailed appendixes give average duration, frequency, and depth of flooding; canopy, subcanopy, and ground-cover vegetation; and taxonomic classification, series, and profile descriptions of soils for each plot. Topographic relief, range in stage, and depth of flooding were greatest on the alluvial flood plain of the Ochlockonee River, the largest of the four streams. Soils were silty in the lower elevations of the flood plain, and tree communities were distinctly different in each topographic zone. The Aucilla River flood plain was dominated by levees and terraces with very few depressions or low backwater areas. Oaks dominated the canopy of both lower and upper terraces of the Aucilla flood plain. Telogia Creek is a blackwater stream that is a major tributary of the Ochlockonee River. Its low, wet flood plain was dominated by Wyssa ogeche (Ogeechee tupelo) trees, had soils with mucky horizons, and was inundated by frequent floods of very short duration. The St. Marks River, a spring-fed stream with high base flow, had the least topographic relief and lowest range in stage of the four streams. St. Marks soils had a higher clay content than the other streams, and limestone bedrock was relatively close to the surface. Wetland determinations of the study plots based on State and Federal regulatory criteria were evaluated. Most State and Federal wetland determinations are based primarily on vegetation and soil characteristics because hydrologic records are usually not available. In this study, plots were located near long-term gaging stations, thus wetland determinations based on plant and soil characteristics could be evaluated at sites where long-term hydrologic conditions were known. Inconsistencies among hydrology, vegetation, and soil determinations were greatest on levee communities of the Ochlockonee and Aucilla River flood plains. Duration of average annual longest flood was almost 2 weeks for both plots. The wetland species list currently used (1991) by the State lacks many ground-cover species common to forested flood plains of north Florida rivers. There were 102 ground-cover species considered upland plants by the State that were present on the nine annually flooded plots of this study. Among them were 34 species that grew in areas continuously flooded for an average of 5 weeks or more each year. Common flood-plain species considered upland plants by the State were: Hypoxis leptocarpa (yellow star-grass), and two woody vines, Brunnichia ovata (ladies' eardrops) and Campsis radican s (trumpet-creeper), which were common in areas flooded continuously for 6 to 9 weeks a year; Sebastiania fruticosa (Sebastian-bush), Chasmanthium laxum (spikegrass), and Panicum dichotomum (panic grass), which typically grew in areas flooded an average of 2 to 3 weeks or more per year; Vitis rotundifolia (muscadine) and Toxicodendron radicans (poison-ivy), usually occurring in areas flooded an average of 1 to 2 weeks a year; and Quercus virginiana (live oak) present most often in areas flooded approximately 1 week a year. Federal wetland regulations (1989) limited wetland jurisdiction to only those areas that are inundated or saturated during the growing season. However, year-round hydrologic records were chosen in this report to describe the influence of hydrology on vegetation, because saturation, inundation, or flowing water can have a variety of both beneficial and adverse effects on flood-plain vegetation at any time of the year. These effects can occur because: (1) Soil temperatures in north Florida are probably high enough in winter for anaerobic conditions to develop in saturated soils. (2) Many plants in the flood plains of north Florida are active in the nongrowing season and might be adapted to anaerobic conditions in winter. (3) Other effects of standing water, such as decreased light penetration, prevention of seed germination, and protection of seeds from herbivores; and effects of flowing water, such as scouring and deposition of sediments, seed dispersal, and mechanical injury, can occur any time of year.

Florida↗
USGS2013

Assessment of water-quality data from Long Lake National Wildlife Refuge, North Dakota--2008 through 2012

ong Lake National Wildlife Refuge, located in south-central North Dakota, is an important habitat for numerous migratory birds and waterfowl, including several threatened or endangered species. The refuge is distinguished by Long Lake, which is approximately 65 square kilometers and consists of four primary water management units. Water levels in the Long Lake units are maintained by low-level dikes and water-control structures, which after construction during the 1930s increased the water-storage capacity of Long Lake and reduced the frequency and volume of flushing flows downstream. The altered water regime, along with the negative precipitation:evaporation ratio of the region, may be contributing to the accumulation of water-borne chemical constituents such as salts, trace metals, and other constituents, which at certain threshold concentrations may impair aquatic plant, invertebrate, and bird communities of the refuge. The refuge’s comprehensive conservation planning process identified the need for water-quality monitoring to assess current (2013) conditions, establish comparative baselines, evaluate changes over time (trends), and support adaptive management of the wetland units. In 2008, the U.S. Geological Survey, U.S. Fish and Wildlife Service, and North Dakota Department of Health began a water-quality monitoring program at Long Lake National Wildlife Refuge to address these needs. Biweekly water-quality samples were collected for ions, trace metals, and nutrients; and in situ sensors and data loggers were installed for the continuous measurement of specific conductance and water depth. Long Lake was characterized primarily by sodium, bicarbonate, and sulfate ions. Overall results for total alkalinity and hardness were 580 and 329 milligrams per liter, respectively; thus, Long Lake is considered alkaline and classified as very hard. The mean pH and sodium adsorption ratio for Long Lake were 8.8 and 10, respectively. Total dissolved solids concentrations averaged approximately 1,750 milligrams per liter, and ranged from 117 to 39,700 milligrams per liter. Twelve of the 14 trace metals detected in the water samples had established North Dakota water-quality standards for aquatic life, and only aluminum and copper consistently exceeded these criteria. Aluminum is considered harmful to aquatic biota in acidic (pH less than 5.5) systems and most of the copper standard exceedances were collected from highly concentrated waters because of evaporation and seasonally low water levels. Concentrations for various forms of nitrogen and phosphorus generally were similar to reported regional values. Specific conductance of Long Lake varied seasonally and annually both within and among management units, with values ranging from less than 500 to nearly 40,000 microsiemens per centimeter at 25 degrees Celsius. Long Lake was characterized by consistent seasonal patterns of increasing specific conductance from spring (March and April) to fall (September and October), with levels stabilizing through the end of the sampling season (November). These seasonal patterns in specific conductance were associated with decreasing water levels throughout the summer due primarily to evaporation and continuous water releases through the Unit 1 outlet structure, which resulted in the concentration of salts. Specific conductance of each unit, along with water levels, also varied among years. Overall, specific conductance levels were greatest during the drier year of 2008 when water levels were low. Specific conductance levels were lowest during the spring of 2009 following above-average volumes of fresh water from snowmelt runoff. Comparisons of specific conductance among sample sites that were spatially distributed within each management unit suggested that spatial variability within units was low except for areas associated with local inflows. Data collected during this study revealed consistent seasonal patterns and low within-unit spatial variability of specific conductance. Based on these data results, future sample collection efforts may be reduced, as well as the number of sample locations, to limit sampling costs. Water-quality samples collected monthly or seasonally during the growing season (spring, summer, and fall) from a single representative location within each water-management unit should provide sufficient data to assess seasonal changes in water-quality over time and provide information for Long Lake management decisions.

North Dakota↗
USGS2008

Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California

With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Plate 3 Susceptibility to Shallow Landsliding Modeled for the Cities of Oakland and Piedmont Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Plate 4 Seismic Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California by Scott B. Miles and David K. Keefer III The relative hazard for each of several landslide scenarios is presented as a geospatial database. This publication includes ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 8.1.2 grids and associated tables and four text files of FGDC-compliant metadata for each grid.

Scientific Investigations Report↗
USGS2015

Hydrology of the middle San Pedro area, southeastern Arizona

In the middle San Pedro Watershed in southeastern Arizona, groundwater is the primary source of water supply for municipal, domestic, industrial, and agricultural use. The watershed comprises two smaller subareas, the Benson subarea and the Narrows-Redington subarea. Early 21st century projections for heavy population growth in the watershed have not yet become a reality, but increased groundwater withdrawals could have undesired consequences - such as decreased base flow to the San Pedro River, and groundwater-level declines - that would lead to the need to deepen existing wells. This report describes the hydrology, hydrochemistry, water quality, and development of a groundwater budget for the middle San Pedro Watershed, focusing primarily on the elements of groundwater movement that could be most useful for the development of a groundwater model Precipitation data from Tombstone, Arizona, and base flow at the stream-gaging station on the San Pedro River at Charleston both show relatively dry periods during the 1960s through the mid-1980s and in the mid-1990s to 2009, and wetter periods from the mid-1980s through the mid-1990s. Water levels in four out of five wells near the mountain fronts show cyclical patterns of recharge, with rates of recharge greatest in the early 1980s through the mid-1990s. Three wells near the San Pedro River recorded their lowest levels during the 1950s to the mid-1960s. The water-level record from one well, completed in the confined part of the coarse-grained lower basin fill, showed a decline of approximately 21 meters. Annual flow of the San Pedro River, measured at the Charleston and Redington gages, has decreased since the 1940s. The median annual streamflow and base flow at the gaging station on the river near Tombstone has decreased by 50 percent between the periods 1968–1986 and 1997–2009. Estimates of streamflow infiltration along the San Pedro River during 1914–2009 have decreased 44 percent, with the largest decreases in the months June–October in the Benson subarea. In the Narrows-Redington subarea, streamflow infiltration has decreased about 65 percent during 1914–2009. The average annual outflow (27.6 hm 3 /year [cubic hectometers per year]) from the Benson subarea aquifer for water years 2001 through 2009 exceeded the inflows (20.0 hm 3 / yr) by 7.60 hm 3 /yr. In the Narrows-Redington subarea for the same period, the average annual outflow (15.7 hm 3 /yr) from the aquifer system exceeded the inflows (13.8 hm 3 /yr) by nearly 2 hm 3 /yr. The largest withdrawals of groundwater in both subareas are for irrigation; these withdrawals peaked in 1973 and have been steadily decreasing since then. Recharge from streamflow infiltration exceeded recharge from the mountain-front and from ephemeral channels in the Benson subarea. In the Narrows-Redington subarea, however, recharge from mountain-front and ephemeral channel recharge exceeded recharge from streamflow infiltration. Evapotranspiration by phreatophytes accounts for the largest outflow of groundwater for both subareas—78 percent of the outflow in the Narrows-Redington subarea and 62 percent of the outflow in the Benson subarea. Precipitation, surface-water, and groundwater chemistry and isotope data indicated the relative age and residence time of groundwater, the amount of interaction between geologic sources and groundwater, and how recharge elevation and season were related to the presence of modern water. The bedrock aquifer receives modern recharge (

Arizona↗
USGS2012

Occurrence of pesticides in water and sediment collected from amphibian habitats located throughout the United States, 2009-10

Water and bed-sediment samples were collected by the U.S. Geological Survey (USGS) in 2009 and 2010 from 11 sites within California and 18 sites total in Colorado, Georgia, Idaho, Louisiana, Maine, and Oregon, and were analyzed for a suite of pesticides by the USGS. Water samples and bed-sediment samples were collected from perennial or seasonal ponds located in amphibian habitats in conjunction with research conducted by the USGS Amphibian Research and Monitoring Initiative and the USGS Toxic Substances Hydrology Program. Sites selected for this study in three of the states (California, Colorado, and Orgeon) have no direct pesticide application and are considered undeveloped and remote. Sites selected in Georgia, Idaho, Louisiana, and Maine were in close proximity to either agricultural or suburban areas. Water and sediment samples were collected once in 2009 during amphibian breeding seasons. In 2010, water samples were collected twice. The first sampling event coincided with the beginning of the frog breeding season for the species of interest, and the second event occurred 10-12 weeks later when pesticides were being applied to the surrounding areas. Additionally, water was collected during each sampling event to measure dissolved organic carbon, nutrients, and the fungus, Batrachochytrium dendrobatidis , which has been linked to amphibian declines worldwide. Bed-sediment samples were collected once during the beginning of the frog breeding season, when the amphibians are thought to be most at risk to pesticides. Results of this study are reported for the following two geographic scales: (1) for a national scale, by using data from the 29 sites that were sampled from seven states, and (2) for California, by using data from the 11 sampled sites in that state. Water samples were analyzed for 96 pesticides by using gas chromatography/mass spectrometry. A total of 24 pesticides were detected in one or more of the 54 water samples, including 7 fungicides, 10 herbicides, 4 insecticides, 1 synergist, and 2 pesticide degradates. On a national scale, aminomethylphosphonic acid (AMPA), the primary degradate of the herbicide glyphosate, which is the active ingredient in Roundup®, was the most frequently detected pesticide in water (16 of 54 samples) followed by glyphosate (8 of 54 samples). The maximum number of pesticides observed at a single site was nine compounds in a water sample from a site in Louisiana. The maximum concentration of a pesticide or degradate observed in water was 2,880 nanograms per liter of clomazone (a herbicide) at a site in Louisiana. In California, a total of eight pesticides were detected among all of the low and high elevation sites; AMPA was the most frequently detected pesticide, but glyphosate was detected at the highest concentrations (1.1 micrograms per liter). Bed-sediment samples were analyzed for 94 pesticides by using accelerated solvent extraction, gel permeation chromatography for sulfur removal, and carbon/alumina stacked solid-phase extraction cartridges to remove interfering sediment matrices. In bed sediment, 22 pesticides were detected in one or more of the samples, including 9 fungicides, 3 pyrethroid insecticides, p,p' -dichlorodiphenyltrichloroethane ( p,p' -DDT) and its major degradates, as well as several herbicides. Pyraclostrobin, a strobilurin fungicide, and bifenthrin, a pyrethroid insecticide, were detected most frequently. Maximum pesticide concentrations ranged from less than their respective method detection limits to 1,380 micrograms per kilogram (tebuconazole in California). The number of pesticides detected in samples from each site ranged from zero to six compounds. The sites with the greatest number of pesticides were in Maine and Oregon with six pesticides detected in one sample from each state, followed by Georgia with four pesticides in one sample. For California, a total of 10 pesticides were detected among all sites, and 4 pesticides were detected at both low and high elevation sites; tebuconazole and pyraclostrobin were the two most frequently detected pesticides in California. For the other six selected states, the most frequently detected pesticides in bed sediment were pyraclostrobin (detected in 17 of 42 samples), bifenthrin (detected in 14 of 42 samples), and tebuconazole (detected in 10 of 42 samples). The fungus, Batrachochytrium dendrobatidis (Bd), was detected in water samples in sites from four of the seven states during 2009 and 2010, and the number of zoospore equivalents per liter of water in samples where Bd was detected ranged from 1.6 to 343. Bd was not detected in water samples from sites in Georgia, Louisiana, and Oregon.

Data Series↗
USGS2009

Comparative Hydrology, Water Quality, and Ecology of Selected Natural and Augmented Freshwater Wetlands in West-Central Florida

Comparing altered wetlands to natural wetlands in the same region improves the ability to interpret the gradual and cumulative effects of human development on freshwater wetlands. Hydrologic differences require explicit attention because they affect nearly all wetland functions and are an overriding influence on other comparisons involving wetland water quality and ecology. This study adopts several new approaches to quantify wetland hydrologic characteristics and then describes and compares the hydrology, water quality, and ecology of 10 isolated freshwater marsh and cypress wetlands in the mantled karst landscape of central Florida. Four of the wetlands are natural, and the other six have water levels indirectly lowered by ground-water withdrawals on municipally owned well fields. For several decades, the water levels in four of these altered wetlands have been raised by adding ground water in a mitigation process called augmentation. The two wetlands left unaugmented were impaired because their water levels were lowered. Multifaceted comparisons between the altered and natural wetlands are used to examine differences between marshes and cypress wetlands and to describe the effects of augmentation practices on the wetland ecosystems. In the karstic geologic setting, both natural and altered wetlands predominantly lost water to the surficial aquifer. Water leaking out of the wetlands created water-table mounds below the wetlands. The smallest mounds radiated only slightly beyond the vegetated area of the wetlands. The largest and steepest mounds occurred below two of the augmented wetlands. There, rapid leakage rates regenerated a largely absent surficial aquifer and mounds encompassed areas 7-8 times as large as the wetlands. Wetland leakage rates, estimated using a daily water-budget analysis applied over multiple years and normalized as inches per day, varied thirtyfold from the slowest leaking natural wetland to the fastest leaking augmented wetland. Leakage rates increased as the size of the flooded area decreased and as the downward head difference between the wetland and the underlying Upper Floridan aquifer increased. Allowing one of the augmented wetlands to dry up for about 2.5 months in the spring of 2004, and then refilling it, generated a net savings of augmentation water despite the amount of water required to recreate the water-table mound beneath the wetland. Runoff from the surrounding uplands was an important component of the water budget in all of the unaugmented wetlands and two of the augmented wetlands. At a minimum, runoff contributed from half (45 percent) to twice (182 percent) as much water as direct rainfall at individual wetlands. Wetland flooded areas, derived using wetland water levels and bathymetric data and presented as a percentage of total wetland area, were used to compare and contrast hydrologic conditions among the 10 wetlands. The percentages of the natural wetland areas that flooded during the study were comparable, despite differences in the sizes of the wetlands. The percent flooded area in each wetland was calculated daily over the study period and monthly for up to 16 years using historical water-level data. Historical flooding in the natural wetlands spanned a greater range in area and had more pronounced seasonality than historical flooding at either the impaired or augmented wetlands. Flooding in the impaired and natural wetlands was similar, however, during 2 years of the study with substantially reduced well-field pumping and above average rainfall. Comparisons indicated several hydrologic differences between the marsh and cypress wetlands in this study. The natural and impaired marshes leaked at about half the rate of the natural and impaired cypress wetlands, and the marshes collectively were underlain by geologic material with lower vertical leakance values than the cypress wetlands. The natural marshes had higher evaporation rates compared to cypress

Professional Paper↗
USGS2002

Geohydrology of a deep-aquifer system monitoring-well site at Marina, Monterey County, California

In 2000, a deep-aquifer system monitoring-well site (DMW1) was completed at Marina, California to provide basic geologic and hydrologic information about the deep-aquifer system in the coastal region of the Salinas Valley. The monitoring-well site contains four wells in a single borehole; one completed from 930 to 950 feet below land surface (bls) in the Paso Robles Formation (DMW1-4); one 1,040 to 1,060 feet below land surface in the upper Purisima Formation (DMW1-3); one from 1,410 to 1,430 feet below land surface in the middle Purisima Formation (DMW1-2); and one from 1,820 to 1,860 feet below land surface in the lower Purisima Formation (DMW1-1). The monitoring site is installed between the coast and several deep-aquifer system supply wells in the Marina Coast Water District, and the completion depths are within the zones screened in those supply wells. Sediments below a depth of 955 feet at DMW1 are Pliocene age, whereas the sediments encountered at the water-supply wells are Pleistocene age at an equivalent depth. Water levels are below sea level in DMW1 and the Marina Water District deep-aquifer system supply wells, which indicate that the potential for seawater intrusion exists in the deep-aquifer system. If the aquifers at DMW1 are hydraulically connected with the submarine outcrops in Monterey Bay, then the water levels at the DMW1 site are 8 to 27 feet below the level necessary to prevent seawater intrusion. Numerous thick fine-grained interbeds and confining units in the aquifer systems retard the vertical movement of fresh and saline ground water between aquifers and restrict the movement of seawater to narrow water-bearing zones in the upper-aquifer system.Hydraulic testing of the DMW1 and the Marina Water District supply wells indicates that the tested zones within the deep-aquifer system are transmissive water-bearing units with hydraulic conductivities ranging from 2 to 14.5 feet per day. The hydraulic properties of the supply wells and monitoring wells are similar, even though the wells are completed in different geologic formations.Geophysical logs collected at the DMW1 site indicate saline water in most water-bearing zones shallower than 720 feet below land surface and from about 1,025 to 1,130 feet below land surface, and indicate fresher water from about 910 to 950 feet below land surface (DMW1-4), 1,130 to 1,550 feet below land surface, and below 1,650 feet below land surface. Temporal differences between electromagnetic induction logs indicate possible seasonal seawater intrusion in five water-bearing zones from 350 to 675 feet below land surface in the upper-aquifer system.The water-chemistry analyses from the deep-aquifer system monitoring and supply wells indicate that these deep aquifers in the Marina area contain potable water with the exception of the saline water in well DMW1-3. The saline water from well DMW1-3 has a chloride concentration of 10,800 milligrams per liter and dissolved solids concentration of 23,800 milligrams per liter. The source of this water was determined not to be recent seawater based on geochemical indicators and the age of the ground water. The high salinity of this ground water may be related to the dissolution of salts from the saline marine clays that surround the water-bearing zone screened by DMW1-3. The major ion water chemistry of the monitoring wells and the nearby MCWD water-supply wells are similar, which may indicate they are in hydraulic connection, even though the stratigraphic layers differ below 955 feet below land surface.No tritium was detected in samples from the deep monitoring wells. The lack of tritium suggest that there is no recent recharge water (less than 50 years old) in the deep-aquifer system at the DMW1 site. The carbon-14 analyses of these samples indicate ground water from the monitoring site was recharged thousands of years ago.

California↗
USGS2016

Characterization and relation of precipitation, streamflow, and water-quality data at the U.S. Army Garrison Fort Carson and Piñon Canyon Maneuver Site, Colorado, water years 2013–14

To evaluate the influence of military training activities on streamflow and water quality, the U.S. Geological Survey, in cooperation with the U.S. Department of the Army, began a hydrologic data collection network on the U.S. Army Garrison Fort Carson in 1978 and on the Piñon Canyon Maneuver Site in 1983. This report is a summary and characterization of the precipitation, streamflow, and water-quality data collected at 43 sites between October 1, 2012, and September 30, 2014 (water years 2013 and 2014). Variations in the frequency of daily precipitation, seasonal distribution, and seasonal and annual precipitation at 5 stations at the U.S. Army Garrison Fort Carson and 18 stations at or near the Piñon Canyon Maneuver Site were evaluated. Isohyetal diagrams indicated a general pattern of increase in total annual precipitation from east to west at the U.S. Army Garrison Fort Carson and the Piñon Canyon Maneuver Site. Between about 54 and 79 percent of daily precipitation was 0.1 inch or less in magnitude. Precipitation events were larger and more frequent between July and September. Daily streamflow data from 16 sites were used to evaluate temporal and spatial variations in streamflow for the water years 2013 and 2014. At all sites, median daily mean streamflow for the 2-year period ranged from 0.0 to 9.60 cubic feet per second. Daily mean streamflow hydrographs are included in this report. Five sites on the Piñon Canyon Maneuver Site were monitored for peak stage using crest-stage gages. At the Piñon Canyon Maneuver Site, five sites had a stage recorder and precipitation gage, providing a paired streamflow-precipitation dataset. There was a statistically significant correlation between precipitation and streamflow based on Spearman’s rho correlation (rho values ranged from 0.17 to 0.35). Suspended-sediment samples were collected in April through October for water years 2013–14 at one site at the U.S. Army Garrison Fort Carson and five sites at the Piñon Canyon Maneuver Site. Suspended-sediment-transport curves were used to illustrate the relation between streamflow and suspended-sediment concentration. All these sediment-transport curves showed a streamflow dependent suspended-sediment concentration relation except for the U.S. Geological Survey station Bent Canyon Creek at mouth near Timpas, CO. Water-quality data were collected and reported from seven sites on the U.S. Army Garrison Fort Carson and the Piñon Canyon Maneuver Site during water years 2013–14. Sample results exceeding an established water-quality standard were identified. Selected water-quality properties and constituents were stratified to compare spatial variation among selected characteristics using boxplots. Trilinear diagrams were used to classify water type based on ionic concentrations of water-quality samples collected during the study period. At the U.S. Army Garrison Fort Carson and the Piñon Canyon Maneuver Site, 27 samples were classified as very hard or brackish. Seven samples had a lower hardness character relative to the other samples. Four of those nine samples were collected at two U.S. Geological Survey stations (Turkey Creek near Fountain, CO, and Little Fountain Creek above Highway 115 at Fort Carson, CO), which have different geologic makeup. Three samples collected at the Piñon Canyon Maneuver Site had a markedly lower hardness likely because of dilution from an increase in streamflow.

Colorado↗
USGS2024

Distribution, abundance, breeding activities, and habitat use of the Least Bell's Vireo at Marine Corps Base Camp Pendleton, California—2023 annual report

Executive Summary The purpose of this report is to provide the Marine Corps with an annual summary of abundance, breeding activity, demography, and habitat use of endangered Least Bell’s Vireos ( Vireo bellii pusillus ) at Marine Corps Base Camp Pendleton, California (MCBCP or Base). Surveys for the Least Bell's Vireo were completed at MCBCP between April 11 and July 20, 2023. Core survey areas and a subset of non-core areas in drainages containing riparian habitat suitable for vireos were surveyed two to four times. We detected 561 territorial male vireos and 28 transient vireos in core survey areas. An additional 103 territorial male vireos and 15 transients were detected in non-core survey areas. Transient vireos were detected on 10 of the 15 drainages/sites surveyed (core and non-core areas). In core survey areas, 90 percent of vireo territories were on the four most populated drainages, with the Santa Margarita River containing 72 percent of all territories in core areas surveyed on Base. In core areas, 79 percent of male vireos were confirmed as paired; 69 percent of male vireos in non-core areas were confirmed as paired. The number of documented Least Bell’s Vireo territories in core survey areas on MCBCP decreased 2 percent from 2022. In two core survey area drainages, the number of territories increased by at least three, and in two core survey area drainages, the number of vireo territories decreased by at least four between 2022 and 2023. The number of vireo territories at the lower San Luis Rey River increased 2 percent from 2022, in contrast to the decrease at MCBCP; however, this change was negligible overall. Although the 10-percent decrease at Marine Corps Air Station, Camp Pendleton from 2022 to 2023 was superficially less trivial, this 10-percent decrease represented the loss of a single territory. The proportion of surveys during which Brown-headed Cowbirds ( Molothrus ater ) were detected decreased to 0.20 from a peak of 0.45 in 2022. Cowbirds were detected from April through July in 2023. Most core-area vireos (62 percent, including transients) used mixed willow ( Salix spp.) riparian habitat. An additional 7 percent of birds occupied willow habitat co-dominated by Western sycamores ( Platanus racemosa ) or Fremont cottonwoods ( Populus fremontii ). Riparian scrub dominated by mule fat ( Baccharis salicifolia ), sandbar willow ( S. exigua ), or blue elderberry ( Sambucus mexicana ) was used by 29 percent of vireos. Habitat dominated by coast live oak ( Quercus agrifolia ) and sycamore or non-native habitat was used by 1 percent of vireos; fewer than 1 percent of vireo territories were in upland scrub and habitat dominated by white alder ( Alnus rhombifolia ). In 2019, MCBCP began operating an artificial seep along the Santa Margarita River; then in 2021, two additional artificial seeps became operational. The artificial seeps pumped water to the surface starting in March and ending in August each year during daylight hours and were designed to increase the amount of surface water present to enhance Southwestern Willow Flycatcher ( Empidonax traillii extimus ) breeding habitat. Although this enhancement was designed to benefit flycatchers, few flycatchers have inhabited MCBCP, including the seep areas, within the past several years; therefore, vireos were selected as a surrogate species to determine effects of the habitat enhancement. This report presents the fourth year of analyses of vireo and vegetation response to the artificial seeps. In 2020, we established four study sites along the Santa Margarita River, two surrounding and extending downstream of seep pumps at the Old Treatment Ponds and along Pump Road, and two Reference sites in similar habitat but further downstream of the Seep sites. In 2023, seep pumps at one Seep site did not function, and we recategorized that study site as Intermediate. Soil moisture was higher at sites that had surface water augmentation (Seep and Intermediate sites) than at the Reference site, and soil moisture also decreased with increasing distance from the seep pumps. We sampled vegetation at these sites to determine the effects of surface water enhancement by seep pumps. Soil moisture was positively related to total foliage cover, woody cover, and native herbaceous cover below 1 meter (m), and also positively related to native herbaceous cover between 1 and 2 m. The Seep site had greater total vegetation cover in the understory (71–79 percent) than the Intermediate (52–66 percent) and Reference (61–69 percent) sites. Total herbaceous cover below 3 m was higher at the Seep site than at the Intermediate site; total herbaceous cover between 1 and 3 m was higher at the Seep site than at the Reference sites. Native herbaceous cover below 3 m was greater at the Seep site than at the Reference sites; native herbaceous cover between 2 and 3 m was also greater at the Seep site than at the Intermediate site. Non-native cover below 3 m was greater at Seep and Reference sites than at the Intermediate site. We found no difference in woody cover among site types at any height. Vireo territory density among the Seep, Intermediate, and Reference sites was similar before the seep pumps were installed. However, vireo territory density at Seep and Intermediate sites combined was significantly higher than at Reference sites after the seep pumps were installed. The U.S. Geological Survey has been color banding Least Bell’s Vireos on Marine Corps Base Camp Pendleton since 1995. By the end of 2022, over 1,000 Least Bell’s Vireos had been color banded on Base. In 2023, we continued to color band and resight color banded Least Bell’s Vireos to evaluate adult survival, site fidelity, between-year movement, and the effect of surface water enhancement on vireo return rate, site fidelity, and between-year movement. We banded 180 Least Bell's Vireos for the first time during the 2023 season, including 1 adult vireo and 179 nestlings. Adult vireos were banded with unique color combinations, whereas nestlings were banded with a single gold numbered federal band on the right leg. We resighted 57 Least Bell's Vireos on Base in 2023 that had been banded before the 2023 breeding season, 20 of which we were unable to identify. Of the 37 that we could identify, 34 were banded on Base, 2 were originally banded on the San Luis Rey River, and 1 was banded at Marine Corps Air Station, Camp Pendleton. Adult birds of known age ranged from 1 to 8 years old. Base-wide survival of vireos was affected by sex, age, and year. Males had significantly higher annual survival than females. Adults had higher annual survival than first-year vireos. Survival for adults and first-year birds was lowest from 2020 to 2021 and highest from 2007 to 2008 and from 2012 to 2013. The return rate of adult vireos to Seep, Intermediate, or Reference sites was not affected by the original banding site (Seep versus Intermediate versus Reference). Most returning adult vireos, predominantly males, showed strong between-year site fidelity. Of the adults present in 2022, 88 percent (96 percent of males; 25 percent of females) returned in 2023 to within 100 m of their previous territory. The discrepancy between male and female return rates follows the pattern observed in previous years. The average between-year movement for returning adult vireos was 0.4±1.9 kilometers (km). The average movement of first-year vireos detected in 2023 that fledged from a known nest on MCBCP in 2022 was 0.9±0.5 km. We monitored Least Bell's Vireo pairs to evaluate the effects of surface water enhancement on nest success and breeding productivity. We monitored vireo nesting activity at 13 territories in the Seep site, 12 territories at the Intermediate site, and 25 territories in the Reference sites between April 8 and July 26. All territories except one at a Seep site and one at a Reference site were occupied by pairs, and all were fully monitored, meaning that all nesting attempts were monitored at these territories. During the monitoring period, 99 nests (26 in the Seep site, 28 at the Intermediate site, and 45 in Reference sites) were monitored. Breeding productivity was similar among Seep, Intermediate, and Reference sites (2.9, 3.6, and 3.0 young fledged per pair, respectively), and a similar percentage of pairs at Seep, Intermediate, and Reference sites fledged at least 1 young (83, 83, and 96 percent, respectively). Other measures of breeding productivity were also similar among Seep, Intermediate, and Reference site pairs. According to the best model, daily nest survival in 2023 was not related to site. Fledging success appeared lower at Intermediate and Seep sites than at the Reference sites in 2023 (48, 46, and 67 percent, respectively), although the difference was not statistically significant. Predation was believed to be the primary source of nest failure at all sites. Predation accounted for 85, 77, and 71 percent of nest failures at Seep, Intermediate, and Reference sites, respectively. Failure of the remaining nests was attributed to infertile eggs, collapse of the vegetation supporting the nest, and other unknown causes. We found no relationships between vireo productivity and understory (below 3 m) vegetation cover. Vireos placed their nests in 15 plant species in 2023. We found few differences in nest placement between successful and unsuccessful vireo nests. At Reference sites, successful vireo nests were placed slightly but significantly higher in the vegetation than unsuccessful nests, and at Intermediate sites, successful nests were placed significantly closer to the edge of the nest plant than unsuccessful nests. We did not find differences in nest placement among Seep, Intermediate, and Reference sites. We found that as bio-year precipitation increased, the number of fledglings produced per vireo pair also increased. We did not find a link between bio-year precipitation and adult survival.

California↗
USGS2026

Hydrogeology of the Tully Valley and characterization of mudboil activity, Onondaga County, New York

Mudboil activity in the Tully Valley, in central New York, is causing turbidity in nearby Onondaga Creek, where it has caused a bridge to collapse; it also has threatened or damaged other structures and has caused extensive land subsidence. Mudboil activity was intermittent from its first reported appearance in the 1890's until the 1970's, when the rates of mudboil discharge and land subsidence began to increase. Historically, the water discharged from mudboils was reported as fresh, but chemical analyses in the late 1970's indicated an increase in specific conductance and chloride concentration. Mudboil discharge is driven by artesian pressure in unconsolidated sediments that are confined by a 60-foot layer of silt and red clay. This process, once begun, has been self-propagating. Artesian pressures are about 20 feet above land surface over most of the valley floor but exceed 30 feet above land surface along Onondaga Creek where Rattlesnake Gulf and Rainbow Creek enter the Tully Valley. The source of artesian pressure is recharge from the Tully (Valley Heads) Moraine at the south end of the valley, and the alluvial fans of Rattlesnake Gulf and Rainbow Creek. The mudboils are found within a 300-foot-wide by 1,500-foot-long corridor along Onondaga Creek just upstream from the two alluvial fans, and in a 5-acre subsided area just west of that corridor. Remediation efforts have entailed (1) diversion of flow from the tributary that feeds the subsided area, (2) installation of depressurizing wells at several locations, and (3) construction of a dam and settling impoundment to detain mudboil sediment that would normally discharge to Onondaga Creek. These efforts have been partly successful, but further work is needed to slow the mudboil activity, which is expected to persist in both areas. Mudboil activity is normally greatest during the early spring and late fall, when artesian pressures increase in response to seasonal ground-water recharge. Suspended-sediment concentrations at the out-flow of the subsidence area ranged from 31,210 mg/L (milligrams per liter) in October 1991 to 17 mg/L after remediation efforts in the summer of 1993. Yearly average suspended-sediment loads to Onondaga Creek from the subsidence area for water years 1992, 1993, 1994, and 1995 were 29.8, 9.75, 1.41, and 1.80 tons per day, respectively. Sediment discharged from the mudboils initially was 30 to 60 percent clay and 80 to 100 percent silt-sized or smaller sediment, and the sand fraction never exceeded 20 percent. After the remediation projects, 50 to 80 percent was clay, and nearly all sediment was silt size or smaller. Analyses of water from upstream and downstream of the subsidence area, as well as from mudboil vents within that area, indicate that the source of water for some mudboils is a confined freshwater aquifer, whereas for others it is an underlying, brackish-water aquifer. Water from the freshwater aquifer has specific conductance values ranging from about 400 ( μS /cm (microsiemens per centimeter at 25° Celsius) to almost 900 ( μS /cm, dissolved chloride concentrations range from 37 to 430 mg/L, and dissolved-solids concentrations range from 215 to 463 mg/L. Specific conductance of water from the brackish-water aquifer ranges from 17,000 to 28,000 ( μS /cm, chloride concentrations range from 2,000 to 7,100 mg/L, and dissolved-solids concentrations range from 4,200 to 12,800 mg/L. The largest landslide in New York State in the last 75 years occurred at the foot of Bare Mountain, 1 mile downstream from the mudboil area, in April 1993 and was the fourth in a series of slides that have occurred at the base of this hill. Slope instability was reported as early as May 1990. After the slide, intermittent mudboil-like activity was observed at several springs within the backscarp of the slide; water from these springs ranged from fresh to brackish. The chemical similarity between water from some springs in the backscarp area and water in the lower (brackish) aquifer beneath the mudboil area may indicate a hydraulic connection between this aquifer and the surficial deposits. Hydrologic changes in the valley during the last 100 years have been attributed to salt-solution mining in the upstream (southern) end of the valley. The removal of nearly 150 feet of salt from four evaporite beds in the Syracuse Shale of the Salina Group has caused the collapse of bedrock and unconsolidated deposits in and near the brine field, 3 miles south of the mudboil area. These collapses have created a hydraulic connection among bedding plane aquifers in the bedrock and increased the hydraulic connection with unconsolidated aquifers. The ground-water flow system after brine field closure in 1988 may have reached a new semiequilibrium, but mudboil activity will likely continue because artesian pressures remain. Whether mudboils were present before salt solution-mining began is unknown.

New York↗
USGS2016

Demographics and movements of least terns and piping plovers in the Central Platte River Valley, Nebraska

The Central Platte River Valley provides breeding habitat for a variety of migratory birds, including federally endangered interior least terns ( Sternula antillarum ; least tern) and threatened piping plovers ( Charadrius melodus ). Since 2009, researchers have collected demographic data on both species that span their lifecycle (that is, from egg laying through survival of adults). Demographic data were used to estimate vital rates (for example, nest survival, chick survival, and so on) for both species and assess how these vital rates were related to type and age of nesting habitat. Nest survival of both species was unrelated to the age of the site a nest was initiated on. Piping plover chick survival to fledging age was not related to the age of the site it was hatched at, however, the probability of a least tern chick surviving to fledging was higher at older sites. In general there were fewer piping plover nests than least tern nests found at sites created through either the physical construction of a new site or new vegetation management regimes, during 2009–14. Mean daily least tern nest survival was 0.9742 (95-percent confidence interval [CI]: 0.9692–0.9783) and cumulative nest survival was 0.59 (95-percent CI: 0.53–0.65). Mean daily least tern chick survival was 0.9602 (95-percent CI: 0.9515–0.9673) and cumulative survival to fledging was 0.54 (95-percent CI = 0.48–0.61). Annual apparent survival rates were estimated at 0.42 (95-percent CI = 0.22–0.64) for adult least terns nesting in the Central Platte River Valley and an apparent survival rate of 0.14 (95-pecent CI = 0.04–0.41) for juvenile least terns. The number of least tern nests present at sites created during 2009–14 was associated with the age of the site; more least tern nests were associated with older sites. During 2009–14, there were four (less than 1 percent of all chicks marked) least tern chicks hatched from the Central Platte River Valley that were subsequently captured on nests as adults. Two of these least terns returned to nest at the same site they had hatched from. Ten instances were documented in which an adult least tern could either switch to nest at a new location or remain at the previous location with the onset of a new year. In five (50 percent) of these instances, least terns returned to nest on the site where they had nested in a previous year. For piping plovers, mean daily apparent nest survival was 0.9880 (95-pecent CI: 0.9836–0.9912) and cumulative nest survival was 0.66 (95-pecent CI: 0.57–0.74). Mean daily piping plover chick survival was 0.9621 (95-pecent CI: 0.9514–0.9706) and cumulative survival to fledging was 0.46 (95-pecent CI = 0.37– 0.56). The annual apparent survival estimate for adult piping plovers nesting in the Central Platte River Valley was 0.76 (95-pecent CI = 0.65–0.85) and was 0.20 (95-pecent CI = 0.14–0.29) for juvenile piping plovers. The number of piping plover nests present at sites created through either the physical construction of a new site or new vegetation management regimes was also associated with site age, with more piping plover nests associated with older sites; however, in general there were fewer piping plover nests found at created sites than least tern nests. Only first-year adult piping plovers were observed on sites in the first year of availability, whereas older sites had a higher proportion of after-first-year adult piping plovers than first-year adult piping plovers. Twelve piping plover chicks (approximately 3 percent of all chicks marked) hatched from the Central Platte River Valley and were subsequently documented on nests as adults. All piping plovers returned to nest on different sites from the one on which they hatched. A total of 45 instances were documented in which an adult plover could either switch to nest at a new location or remain at the previous location with the onset of a new year. In 39 instances (87 percent), the adult nested on the same site as its prior documented nesting attempt and in 6 of these instances the adult switched to a new nesting location between years. There were 13 of 75 uniquely identifiable piping plovers observed to renest (that is, initiate more than one nest in a season) during 2009–14; no renests were observed among uniquely identifiable least terns. In all but one case, piping plover renests were found at the same site as the first nest initiated that season. For birds that renested, the mean initiation date of the first nest was May 6 and the mean initiation date of the second nest was June 8. On average, renests were initiated 7.5 days plus or minus 7.3 (SD [standard deviation]) following the date the initial nesting attempt was ‘fated’ (considered either failed or hatched).

Nebraska↗
USGS2012

Occurrence of pharmaceuticals, hormones, and organic wastewater compounds in Pennsylvania waters, 2006-09

Concern over the presence of contaminants of emerging concern, such as pharmaceutical compounds, hormones, and organic wastewater compounds (OWCs), in waters of the United States and elsewhere is growing. Laboratory techniques developed within the last decade or new techniques currently under development within the U.S. Geological Survey now allow these compounds to be measured at concentrations in nanograms per liter. These new laboratory techniques were used in a reconnaissance study conducted by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Environmental Protection, to determine the occurrence of contaminants of emerging concern in streams, streambed sediment, and groundwater of Pennsylvania. Compounds analyzed for in the study are pharmaceuticals (human and veterinary drugs), hormones (natural and synthetic), and OWCs (detergents, fragrances, pesticides, industrial compounds, disinfectants, polycyclic aromatic hydrocarbons, fire retardants and plasticizers). Reconnaissance sampling was conducted from 2006 to 2009 to identify contaminants of emerging concern in (1) groundwater from wells used to supply livestock, (2) streamwater upstream and downstream from animal feeding operations, (3) streamwater upstream from and streamwater and streambed sediment downstream from municipal wastewater effluent discharges, (4) streamwater from sites within 5 miles of drinking-water intakes, and (5) streamwater and streambed sediment where fish health assessments were conducted. Of the 44 pharmaceutical compounds analyzed in groundwater samples collected in 2006 from six wells used to supply livestock, only cotinine (a nicotine metabolite) and the antibiotics tylosin and sulfamethoxazole were detected. The maximum concentration of any contaminant of emerging concern was 24 nanograms per liter (ng/L) for cotinine, and was detected in a groundwater sample from a Lebanon County, Pa., well. Seven pharmaceutical compounds including acetaminophen, caffeine, carbamazepine, and the four antibiotics tylosin, sulfadimethoxine, sulfamethoxazole, and oxytetracycline were detected in streamwater samples collected in 2006 from six paired stream sampling sites located upstream and downstream from animal-feeding operations. The highest reported concentration of these seven compounds was for the antibiotic sulfamethoxazole (157 ng/L), in a sample from the downstream site on Snitz Creek in Lancaster County, Pa. Twenty-one pharmaceutical compounds were detected in streamwater samples collected in 2006 from five paired stream sampling sites located upstream or downstream from a municipal wastewater-effluent-discharge site. The most commonly detected compounds and maximum concentrations were the anticonvulsant carbamazepine, 276 ng/L; the antihistamine diphenhydramine, 135 ng/L; and the antibiotics ofloxacin, 329 ng/L; sulfamethoxazole, 1,340 ng/L; and trimethoprim, 256 ng/L. A total of 51 different contaminants of emerging concern were detected in streamwater samples collected from 2007 through 2009 at 13 stream sampling sites located downstream from a wastewater-effluent-discharge site. The concentrations and numbers of compounds detected were higher in stream sites downstream from a wastewater-effluent-discharge site than in stream sites upstream from a wastewater-effluent-discharge site. This finding indicates that wastewater-effluent discharges are a source of contaminants of emerging concern; these contaminants were present more frequently in the streambed-sediment samples than in streamwater samples. Antibiotic compounds were often present in both the streamwater and streambed-sediment samples, but many OWCs were present exclusively in the streambed-sediment samples. Compounds with endocrine disrupting potential including detergent metabolites, pesticides, and flame retardants, were present in the streamwater and streambed-sediment samples. Killinger Creek, a stream where wastewater-effluent discharges contribute a large percentage of the total flow, stands out as a stream with particularly high numbers of compounds detected and detected at the highest concentrations measured in the reconnaissance sampling. Nineteen contaminants of emerging concern were detected in streamwater samples collected quarterly from 2007 through 2009 at 27 stream sites within 5 miles of a drinking-water intake. The number of contaminants and the concentrations detected at the stream sites within 5 miles of drinking-water intakes were generally very low (concentrations less than 50 ng/L), much lower than those at sites downstream from a wastewater-effluent discharge. The most commonly detected compounds and maximum concentrations were caffeine, 517 ng/L; carbamazepine, 95 ng/L; sulfamethoxazole, 146 ng/L; and estrone, 3.15 ng/L. The concentrations and frequencies of detection of some of the contaminants of emerging concern appear to vary by season, which could be explained by compound use, flow regime, or differences in degradation rates. Concentrations of some contaminants were associated with lower flows as a result of decreased in-stream dilution of wastewater effluents or other contamination sources. Twenty-two contaminants of emerging concern were detected once each in streamwater samples collected in 2007 and 2008 from 16 fish-health stream sites located statewide. The highest concentrations were for the OWCs, including flame retardants tri(2-butoxyethyl)phosphate (604 ng/L) and tri(2-chloroethyl)phosphate (272 ng/L) and the fragrance isoquinoline (330 ng/L). Far fewer numbers of contaminants of emerging concern were detected at the fish-health sites than at the wastewater-effluent-discharge sites. Most of the fish-health sites were not located directly downstream from a wastewater-effluent discharge, but there were multiple wastewater-effluent discharges in the drainage basins upstream from the sampling sites. No distinct pattern of contaminant occurrence could be discerned for the fish-health stream sites

Pennsylvania↗
USGS2009

Sources, transport, and storage of sediment at selected sites in the Chesapeake Bay Watershed

The Chesapeake Bay Watershed covers 165,800 square kilometers and is supplied with water and sediment from five major physiographic provinces: Appalachian Plateau, Blue Ridge, Coastal Plain, Piedmont, and the Valley and Ridge. Suspended-sediment loads measured in the Chesapeake Bay Watershed showed that the Piedmont Physiographic Province has the highest rates of modern (20th Century) sediment yields, measured at U.S. Geological Survey streamflow-gaging stations, and the lowest rates of background or geologic rates of erosion (~10,000 years) measured with in situ beryllium-10. In the agricultural and urbanizing Little Conestoga Creek Watershed, a Piedmont watershed, sources of sediment using the 'sediment-fingerprinting' approach showed that streambanks were the most important source (63 percent), followed by cropland (37 percent). Cesium-137 inventories, which quantify erosion rates over a 40-year period, showed average cropland erosion of 19.39 megagrams per hectare per year in the Little Conestoga Creek Watershed. If this erosion rate is extrapolated to the 13 percent of the watershed that is in cropland, then cropland could contribute almost four times the measured suspended-sediment load transported out of the watershed (27,600 megagrams per hectare per year), indicating that much of the eroded sediment is being deposited in channel and upland storage. The Piedmont has had centuries of land-use change, from forest to agriculture, to suburban and urban areas, and in some areas, back to forest. These land-use changes mobilized a large percentage of sediment that was deposited in upland and channel storage, and behind thousands of mill dams. The effects of these land-use changes on erosion and sediment transport are still being observed today as stored sediment in streambanks is a source of sediment. Cropland is also an important source of sediment. The Coastal Plain Physiographic Province has had the lowest sediment yields in the 20th Century and with sandy soils, contributes little fine-grained sediment. In the agricultural Pocomoke River Watershed, a Coastal Plain watershed, cesium-137 mass-balance results indicate that erosion and deposition are both occurring on cropland fields. Sources of sediment using the sediment-fingerprinting approach for the Pocomoke River were distributed as follows: cropland (46 percent), ditch beds (34 percent), ditch banks and streambanks (7 percent), and forest (13 percent). Cropland was a source of sediment for the two largest peak flow events, which occurred during harvesting when the ground may have been bare. The Pocomoke River Watershed is heavily ditched and channelized, conditions that are favorable for ditch bed and bank erosion. In the mixed land use (forested, agricultural, and urbanizing) Mattawoman Creek Watershed, a Coastal Plain watershed, sources of sediment using the sediment-fingerprinting approach were distributed as follows: streambanks (30 percent), forest (29 percent), construction (25 percent), and cropland (17 percent). Mattawoman Creek Watershed drains a rapidly developing region with 182 hectares (approximately 1.26 percent of the watershed) under construction. Sediment from construction sites was also determined as a source of sediment in the Mattawoman Creek Watershed. The sediment-fingerprinting source results for the three watersheds analyzed, show that in all watersheds, both the stream corridor and agriculture were significant sources of sediment. Forest as a source of sediment in the Mattawoman Creek Watershed may indicate that these forests are being disturbed and forest soils are eroding. Bare ground can be an important sediment source. Spatial analysis of bare ground in the Little Conestoga Creek Watershed using satellite imagery between 2000 and 2005 showed that the majority of bare ground was classified as pasture. Bare ground was correlated to the growing season with the highest percentages occurring in the early spring (April, 34 percent) and a

Chesapeake Bay Watershed↗
USGS2016

Agricultural irrigated land-use inventory for the counties in the Suwannee River Water Management District in Florida, 2015

A detailed inventory of irrigated crop acreage is not available at the level of resolution needed to accurately estimate agricultural water use or to project future water demands in many Florida counties. A detailed digital map and summary of irrigated acreage during the 2015 growing season was developed for 13 of the 15 counties that compose the Suwannee River Water Management District. The irrigated areas were delineated using land-use data, orthoimagery, and information obtained from the water management district consumptive water-use permits that were then field verified between May and November of 2015. Selected attribute data were collected for the irrigated areas, including crop type, primary water source, and type of irrigation system. Results indicate that an estimated 113,134 acres were either irrigated or had potential for irrigation in all or part of the 13 counties within the Suwannee River Water Management District during 2015. This estimate includes 108,870 acres of field-verified, irrigated crops and 4,264 acres of irrigated land observed as (1) idle (with an irrigation system visible but no crop present at the time of the field-verification visit), (2) acres that could not be verified during field visits, or (3) acres that were located on publicly owned research lands. Of the total field-verified crops, 83,721 acres were field crops; 20,962 acres were vegetable crops (sometimes referred to as row crops); 3,089 acres were in tree nurseries, ornamentals, and sod production; and 1,098 acres were fruit crops. Specific irrigated crops included 32,468 acres of corn (primarily for silage); 28,170 acres of peanuts; and 10,331 acres of hay. About 40 percent of the vegetable acreage (8,340 acres) was double cropped (planted with both a spring and a fall crop on the same field). Beans, carrots, and watermelons were the most commonly grown vegetable crops in these 13 counties in 2015. Sprinkler irrigation systems including center pivots, portable or traveling guns, and permanent or solid overhead fixtures accounted for nearly 91 percent (102,874 acres) of the total irrigated acreage in the Suwannee River Water Management District, whereas microirrigation systems including drip irrigation accounted for 9 percent (10,260 acres) of the irrigated acreage. A total of 1,466 center pivots were observed during field verification in 2015 and accounted for 93,093 irrigated acres (which represents 82 percent of the total irrigated acreage). Most center pivots were in use at the time of the field verification, although about 3 percent appeared idle. No flood irrigation systems were observed during field verification in 2015. Overall, groundwater was used to irrigate nearly all of the field-verified acreage (99.8 percent). Dairy wastewater effluent was used on many fields during 2015; however, a quantitative estimate of acreage using effluent could not be determined. Irrigated cropland totaled 26,927 acres in Suwannee County; 16,511 acres in Madison County; 14,862 acres in Hamilton County; and 14,155 acres in Gilchrist County; these four counties accounted for nearly two-thirds (64 percent) of the acres irrigated within the Suwannee River Water Management District during 2015. Corn (primarily for silage) and peanuts were the primary irrigated crops, accounting for 48, 70, and 71 percent, respectively, of the total irrigated acreage in Suwannee, Madison, and Gilchrist Counties; vegetables accounted for 52 percent of the total irrigated acres in Hamilton County. Other counties with substantial irrigated acreage included Levy (10,122 acres), Alachua (9,547 acres), and Lafayette (8,110 acres); these three counties, combined with Suwannee, Madison, Hamilton, and Gilchrist Counties, accounted for 88 percent of the irrigated acreage in the Suwannee River Water Management District. The irrigated acreage that was field verified in 2015 for the 13 counties in the Suwannee River Water Management District (113,134 acres) is about 6 percent higher than the estimated acreage published by the U.S. Department of Agriculture (107,217 acres) for 2012; however, this 2012 value represents acreage for the entire portion of all 13 counties, not just the Suwannee River Water Management District portion. Differences between the 2015 field-verified acreage totals and those published by the U.S. Department of Agriculture for 2012 may occur because (1) irrigated acreage for some specific crops increased or decreased substantially during the 3-year interval due to commodity prices or economic changes, (2) calculated field-verified irrigated acreage may be an overestimate because irrigation was assumed if an irrigation system was present and therefore the acreage was counted as irrigated, when in fact that may not have been the case as some farmers may not have used their irrigation systems during this growing period even if they had a crop in the field, or (3) the amount of irrigated acreages published by the U.S. Department of Agriculture for selected crops may be underestimated in some cases.

Florida↗
USGS2013

Simulation of salinity intrusion along the Georgia and South Carolina coasts using climate-change scenarios

Potential changes in climate could alter interactions between environmental and societal systems and adversely affect the availability of water resources in many coastal communities. Changes in streamflow patterns in conjunction with sea-level rise may change the salinity-intrusion dynamics of coastal rivers. Several municipal water-supply intakes are located along the Georgia and South Carolina coast that are proximal to the present day saltwater-freshwater interface of tidal rivers. Increases in the extent of salinity intrusion resulting from climate change could threaten the availability of freshwater supplies in the vicinity of these intakes. To effectively manage these supplies, water-resource managers need estimates of potential changes in the frequency, duration, and magnitude of salinity intrusion near their water-supply intakes that may occur as a result of climate change. This study examines potential effects of climate change, including altered streamflow and sea-level rise, on the dynamics of saltwater intrusion near municipal water-supply intakes in two coastal areas. One area consists of the Atlantic Intracoastal Waterway (AIW) and the Waccamaw River near Myrtle Beach along the Grand Strand of the South Carolina Coast, and the second area is on or near the lower Savannah River near Savannah, Georgia. The study evaluated how future sea-level rise and a reduction in streamflows can potentially affect salinity intrusion and threaten municipal water supplies and the biodiversity of freshwater tidal marshes in these two areas. Salinity intrusion occurs as a result of the interaction between three principal forces—streamflow, mean coastal water levels, and tidal range. To analyze and simulate salinity dynamics at critical coastal gaging stations near four municipal water-supply intakes, various data-mining techniques, including artificial neural network (ANN) models, were used to evaluate hourly streamflow, salinity, and coastal water-level data collected over a period exceeding 10 years. The ANN models were trained (calibrated) to learn the specific interactions that cause salinity intrusions, and resulting models were able to accurately simulate historical salinity dynamics in both study areas. Changes in sea level and streamflow quantity and timing can be simulated by the salinity intrusion models to evaluate various climate-change scenarios. The salinity intrusion models for the study areas are deployed in a decision support system to facilitate the use of the models for management decisions by coastal water-resource managers. The report describes the use of the salinity-intrusion models decision support system to evaluate salinity-intrusion dynamics for various climate-change scenarios, including incremental increases in sea level in combination with incremental decreases in streamflow. Operation of municipal water-treatment plants is problematic when the specific-conductance values for source water are greater than 1,000 to 2,000 microsiemens per centimeter (µS/cm). High specific-conductance values contribute to taste problems that require treatment. Data from a gage downstream from a municipal water intake indicate specific conductance exceeded 1,000 µS/cm about 5.4 percent of the time over the 14-year period from August 1995 to August 2008. Simulations of specific conductance at this gaging station that incorporates sea-level rises resulted in a doubling of the exceedances to 11.0 percent for a 1-foot increase and 17.6 percent for a 2-foot increase. The frequency of intrusion of water with specific conductance values of 1,000 µS/cm was less sensitive to incremental reductions in streamflow than to incremental increases in sea level. Simulations of conditions associated with a 10-percent reduction in streamflow, in combination with a 1-foot rise in sea level, increased the percentage of time specific conductance exceeded 1,000 µS/cm at this site from 11.0 to 13.3 percent, and a 20-percent reduction in streamflow increased the percentage of time to 16.6 percent. Precipitation and temperature data from a global circulation model were used, after scale adjustments, as input to a watershed model of the Yadkin-Pee Dee River basin, which flows into the Waccamaw River and Atlantic Intracoastal Waterway study area in South Carolina. The simulated streamflow for historical conditions and projected climate change in the future was used as input for the ANN model in decision support system. Results of simulations incorporating climate-change projections for alterations in streamflow indicate an increase in the frequency of salinity-intrusion events and a shift in the seasonal occurrence of the intrusion events from the summer to the fall.

South Carolina↗
USGS1953

Ground-water resources of the Rapid Valley unit, Cheyenne Division, South Dakota, with a section on the surface waters of Rapid Valley

The Rapid Valley unit is in Pennington County, S. Dak., and extends from the east city limits of Rapid City southeastward for 21 miles along Rapid Creek. The bedrock formations that underlie the region are chiefly marine in origin, and they generally dip eastward from the center of the Black Hills uplift. The exposed formations are of Cretaceous age and consist of the Greenhorn limestone, the Carlile shale, the Niobrara formation, and the Pierre shale. The Pierre shale, which underlies the unconsolidated flood plain and terrace deposits in much Of the region is exposed in the erosional slopes along the south side of the valley and in the deeper draws on the north side. The areas in which the other formations are exposed are relatively small and are restricted to the western part of-the region. Four terraces are present on the north side of Rapid Creek. The lowest terrace and the flood plain in the western half of the region are irrigated at the present time, and the two lower terraces and the flood plain in the eastern half have been proposed for irrigation. Abundant supplies of ground water occur in the flood plain and terrace deposits where they are now irrigated. Because the waterbearing materials consist of interfingering layers of differing permeability, the ground water is under water-table conditions in some places whereas it is confined in others. Locally, where there is a confining layer below other water-bearing materials or where a confined layer is itself saturated, the ground water may occur under both water-table and artesian conditions. Seepage from irrigation canals, which is the principal source of recharge, causes high ground-water levels from June to November; as a result, parts of the areas have become waterlogged. In the parts of the region that are not now affected by irrigation, the surface of the ground water is only a few feet above the bedrock surface and 6 ft to 42 ft below land surface; its position is relatively constant throughout the year. Harmful concentrations of salt in the soil are in part due to evaporation of ground water. These are found only locally in the Rapid Valley region and do not present a serious problem at this time. It is thought, however, that the fine-grained materials underlying the Rapid terrace may contain sufficient salt to cause detrimental salt accumulations in the soil if the proposed irrigation causes ground-water levels to rise close to the surface. Lining of the irrigation canals would reduce the amount of seepage and would effect a lowering of ground-water levels, if irrigation practices are extended to other areas, drainage facilities will be necessary both to avoid aggravating the existing conditions of waterlogging and to prevent the waterlogging of other low-lying lands. The flow of Rapid Creek is affected by a variety of conditions. A few miles west of Rapid City, where Rapid Creek flows over the Englewood and Pahasapa limestones and the Minnelusa sandstone, there is a loss of about 8 cfs of water in a distance of a few miles. In the 3-mile reach of Rapid Creek between the Canyon Lake stream-gaging station and the Rapid City stream-gaging station there is a gain of about 20 cfs; much of this gain in flow may be attributed to the inflow from Cleghorn and Jackson springs and to the addition of water from the State-owned cement plant. In the Rapid Valley unit, the flow of the creek during the irrigation season is affected largely by the amount of water diverted for irrigation. The irrigation canals act as bypass channels, much of the water being returned to Rapid Creek by way of spillage into normally dry tributary creek channels and by movement through ground-water bodies that discharge into Rapid Creek.

South Dakota↗
USGS2017

Characterization of streamflow, suspended sediment, and nutrients entering Galveston Bay from the Trinity River, Texas, May 2014–December 2015

The U.S. Geological Survey (USGS), in cooperation with the Texas Water Development Board and the Galveston Bay Estuary Program, collected streamflow and water-quality data at USGS streamflow-gaging stations in the lower Trinity River watershed from May 2014 to December 2015 to characterize and improve the current understanding of the quantity and quality of freshwater inflow entering Galveston Bay from the Trinity River. Continuous streamflow records at four USGS streamflow-gaging stations were compared to quantify differences in streamflow magnitude between upstream and downstream reaches of the lower Trinity River. Water-quality conditions were characterized from discrete nutrient and sedi­ment samples collected over a range of hydrologic conditions at USGS streamflow-gaging station 08067252 Trinity River at Wallisville, Tex. (hereinafter referred to as the “Wallisville site”), approximately 4 river miles upstream from where the Trinity River enters Galveston Bay. Based on streamflow records, annual mean outflow from Livingston Dam into the lower Trinity River was 2,240 cubic feet per second (ft 3 /s) in 2014 and 22,400 ft 3 /s in 2015, the second lowest and the highest, respectively, during the entire period of record (1966–2015). During this study, only about 54 percent of the total volume measured at upstream sites was accounted for at the Wallisville site as the Trinity River enters Galveston Bay. This difference in water volumes between upstream sites and the Wallisville site indicates that at high flows a large part of the volume released from Lake Livingston does not reach Galveston Bay through the main channel of the Trinity River. These findings indicate that water likely flows into wetlands and water bodies surrounding the main channel of the Trinity River before reaching the Wallisville site and is being stored or discharged through other channels that flow directly into Galveston Bay. To characterize suspended-sediment concentrations and loads in Trinity River inflow to Galveston Bay, a regression model was developed to estimate suspended-sediment concentrations by using acoustic backscatter data as a surrogate. The model yielded an adjusted coefficient of determination value of 0.92 and a root mean square error of 1.65 milligrams per liter (mg/L). The mean absolute percentage error between measured and estimated suspended-sediment concentration was 35 percent. During this study, estimated suspended-sediment concentrations ranged from 2 to 701 mg/L, with a mean of 97 mg/L. Suspended-sediment concentrations varied in response to changes in discharge, with peak suspended-sediment concentrations occurring 1 to 2 days before the peak discharge for each event. The total suspended-sediment load at the Wallisville site during May 2014–December 2015 was approximately 2,200,000 tons, with a minimum monthly suspended-sediment load of 100 tons in October 2014 and a maximum monthly load of 441,000 tons in November 2015. Results from nutrient samples collected at the Wallisville site indicate that total nitrogen and total phosphorus concen­trations fluctuated at a similar rate, with the highest nutrient concentrations occurring during periods of high flow corresponding to releases from Lake Livingston. The mean concen­trations of total nitrogen and total phosphorus were approxi­mately 75 percent higher during high flow releases than during periods of low flow, overshadowing variations in nutrient concentrations caused by seasonality at the Wallisville site. Results from the study indicate nutrient delivery to Galveston Bay from the main channel of the Trinity River is likely controlled primarily by high-flow releases from Lake Livingston. For most samples collected at the Wallisville site, organic nitrogen was the predominant form of nitrogen; however, when discharge increased because of releases from Lake Livingston, the percentage of organic nitrogen typically decreased and the percentage of nitrate increased. The concentrations of total phosphorus also increased during high-flow events, likely as a result of suspended sediment within Lake Livingston releases and mobilization of sediment particles in the river channel and flood plain during these periods of high flow. The predominant source of phosphorous to Galveston Bay from the Trinity River is in particulate form closely tied to suspended-sediment concentrations. The changes in nutrient concentration and composition caused by releases from Lake Livingston during this study indicate the reservoir may play an important role in the delivery of nutrients into Galveston Bay. Further study is required to better understand the processes in Lake Livingston influencing the characteristics of nutrient and sediment inflow to Galveston Bay. With phosphorous concentrations correlated to suspended-sediment concentra­tions (coefficient of determination value of 0.75) and with the concentrations of nutrients changing as the discharge changes, the diversion of water and suspended sediment into surround­ing wetlands and channels outside of the main channel of the Trinity River may play a large role in regulating nutrient inputs into Galveston Bay.

Texas↗
USGS2017

Multiple-source tracking: Investigating sources of pathogens, nutrients, and sediment in the Upper Little River Basin, Kentucky, water years 2013–14

The South Fork Little River (SFLR) and the North Fork Little River (NFLR) are two major headwater tributaries that flow into the Little River just south of Hopkinsville, Kentucky. Both tributaries are included in those water bodies in Kentucky and across the Nation that have been reported with declining water quality. Each tributary has been listed by the Kentucky Energy and Environment Cabinet—Kentucky Division of Water in the 303(d) List of Waters for Kentucky Report to Congress as impaired by nutrients, pathogens, and sediment for contact recreation from point and nonpoint sources since 2002. In 2009, the Kentucky Energy and Environment Cabinet—Kentucky Division of Water developed a pathogen total maximum daily load (TMDL) for the Little River Basin including the SFLR and NFLR Basins. Future nutrient and suspended-sediment TMDLs are planned once nutrient criteria and suspended-sediment protocols have been developed for Kentucky. In this study, different approaches were used to identify potential sources of fecal-indicator bacteria (FIB), nitrate, and suspended sediment; to inform the TMDL process; and to aid in the implementation of effective watershed-management activities. The main focus of source identification was in the SFLR Basin. To begin understanding the potential sources of fecal contamination, samples were collected at 19 sites for densities of FIB ( E. coli ) in water and fluvial sediment and at 11 sites for Bacteroidales genetic markers (General AllBac, human HF183, ruminant BoBac, canid BacCan, and waterfowl GFD) during the recreational season (May through October) in 2013 and 2014. Results indicated 34 percent of all E. coli water samples ( n =227 samples) did not meet the U.S. Environmental Protection Agency 2012 recommended national criteria for primary recreational waters. No criterion currently exists for E. coli in fluvial sediment. By use of the Spearman’s rank correlation test, densities of FIB in fluvial sediments were observed to have a statistically significant positive correlation with drainage area. As drainage area increased, so did the densities of FIB in the fluvial sediments. There was no statistically significant correlation between drainage area and FIB in water. The human-associated marker (HF183) was found above the detection limit in 26 percent of the samples ( n =120 samples); a higher proportion of positive samples was in the NFLR Basin. The ruminant-associated marker (BoBac) was above the detection limit in 65 percent of samples; a higher proportion of positive samples was in the headwaters of the SFLR Basin. Nutrient yields differed between the SFLR and NFLR Basins. Comparatively, the SFLR Basin produced the largest estimated mean yields of total nitrogen (16,000 pounds per year per square mile (lb/yr/mi 2 ) and nitrite plus nitrate nitrogen (12,500 lb/yr/mi 2 ), and the NFLR Basin produced the largest estimated mean yields of ammonia plus organic nitrogen (4,700 lb/yr/mi 2 ), total phosphorus (1,100 lb/yr/mi 2 ), and orthophosphorus (590 lb/yr/mi 2 ). Nitrate sources in surface water were assessed in both basins using dual-nitrate isotope (nitrogen and oxygen) ratios. Data from the different land uses in the SFLR Basin showed differences in nitrate concentrations and overlapping, but moderately distinct, isotopic signatures. Predominantly forested sites consistently had low nitrate concentrations (median = 0.233 milligrams per liter) with minimal variability, and agricultural sites had the highest nitrate concentrations (median = 7.55 milligrams per liter) with the greatest variability. The median nitrate concentration for sites with mixed land use was 2.66 milligrams per liter. Dual-isotope data for forested sites plotted within ranges characteristic of soil-derived nitrate with possible but minimal influence from recycled atmospheric nitrate. Ranges of dual-isotope data for sites with agricultural and mixed land uses were characteristic of possible mixtures of chemical fertilizer, soil-derived nitrate, and manure and septic wastes. In the NFLR Basin, a positive linear relation was observed between nitrate concentrations and nitrogen isotope ratios (δ 15 N NO3 ) (R 2 =0.56; p -value <0.001) that potentially suggests the NFLR Basin has a higher proportion of δ 15 N NO3 -enriched sources, such as manure and sewage. However, mixing of other nitrate-derived sources cannot be excluded, because many values of δ 15 N NO3 and concentrations of nitrate showed minimal variation and plotted within dual-nitrate isotope ranges characteristic of fertilizer and soil-derived nitrate sources. A sediment-fingerprinting approach was used to quantify the relative contribution of four upland sources in the SFLR Basin (agricultural, pasture, riparian/forest, and streambank) to understand how land management affects suspended-sediment concentration. Carbon isotope ratios (δ 13 C), together with calcium and carbon concentrations, were the best indicators of sediment source; the uncertainty was less than 11 percent. Fine-sediment samples collected at the SFLR Basin outlet indicated streambanks as the largest source of the fine sediment to the stream followed by cropland and riparian/forest-source areas, respectively; pasture was a minor contributing source. Streambanks and cropland were essentially equal contributors of fine sediment at the NFLR Basin outlet.

Kentucky↗