Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Water Hydrological Data”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,279 records · Page 71Linked to original sources

Simulation of streamflow in small drainage basins in the southern Yampa River basin, Colorado

Coal mining operations in northwestern Colorado commonly are located in areas that have minimal available water-resource information. Drainage-basin models can be a method for extending water-resource information to include periods for which there are no records or to transfer the information to areas that have no streamflow-gaging stations. To evaluate the magnitude and variability of the components of the water balance in the small drainage basins monitored, and to provide some method for transfer of hydrologic data, the U.S. Geological Survey 's Precipitation-Runoff Modeling System was used for small drainage basins in the southern Yampa River basin to simulate daily mean streamflow using daily precipitation and air-temperature data. The study area was divided into three hydrologic regions, and in each of these regions, three drainage basins were monitored. Two of the drainage basins in each region were used to calibrate the Precipitation-Runoff Modeling System. The model was not calibrated for the third drainage basin in each region; instead, parameter values were transferred from the model that was calibrated for the two drainage basins. For all of the drainage basins except one, period of record used for calibration and verification included water years 1976-81. Simulated annual volumes of streamflow for drainage basins used in calibration compared well with observed values; individual hydrographs indicated timing differences between the observed and simulated daily mean streamflow. Observed and simulated annual average streamflows compared well for the periods of record, but values of simulated high and low streamflows were different than observed values. Similar results were obtained when calibrated model parameter values were transferred to drainage basins that were uncalibrated. (USGS)

Colorado↗

Applying downscaled Global Climate Model data to a groundwater model of the Suwannee River Basin, Florida, USA

The application of Global Climate Model (GCM) output to a hydrologic model allows for comparisons between simulated recent and future conditions and provides insight into the dynamics of hydrology as it may be affected by climate change. A previously developed numerical model of the Suwannee River Basin, Florida, USA, was modified and calibrated to represent transient conditions. A simulation of recent conditions was developed for the 372-month period 1970-2000 and was compared with a simulation of future conditions for a similar-length period 2039-2069, which uses downscaled GCM data. The MODFLOW groundwater-simulation code was used in both of these simulations, and two different MODFLOW boundary condition “packages” (River and Streamflow-Routing Packages) were used to represent interactions between surface-water and groundwater features. The hydrologic fluxes between the atmosphere and landscape for the simulation of future conditions were developed from dynamically downscaled precipitation and evapotranspiration (ET) data generated by the Community Climate System Model (CCSM). The downscaled precipitation data were interpolated for the Suwannee River model grid, and the downscaled ET data were used to develop potential ET and were interpolated to the grid. The fu¬ture period has higher simulated rainfall (10.8 percent) and ET (4.5 percent) than the recent period. The higher future rainfall causes simulated groundwater levels to rise in areas where they are deep and have little ET in either the recent or future case. However, in areas where groundwater levels were originally near the surface, the greater future ET causes groundwater levels to become lower despite the higher projected rainfall. The general implication is that unsaturated zone depth could be more spatially uniform in the future and vegetation that requires a range of conditions (substantially wetter or drier than aver¬age) could be detrimentally affected. This vegetation would include wetland species, especially in areas inland from the coast.

Florida↗

Estimating the Magnitude and Frequency of Peak Streamflows for Ungaged Sites on Streams in Alaska and Conterminous Basins in Canada

Estimates of the magnitude and frequency of peak streamflow are needed across Alaska for floodplain management, cost-effective design of floodway structures such as bridges and culverts, and other water-resource management issues. Peak-streamflow magnitudes for the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence-interval flows were computed for 301 streamflow-gaging and partial-record stations in Alaska and 60 stations in conterminous basins of Canada. Flows were analyzed from data through the 1999 water year using a log-Pearson Type III analysis. The State was divided into seven hydrologically distinct streamflow analysis regions for this analysis, in conjunction with a concurrent study of low and high flows. New generalized skew coefficients were developed for each region using station skew coefficients for stations with at least 25 years of systematic peak-streamflow data. Equations for estimating peak streamflows at ungaged locations were developed for Alaska and conterminous basins in Canada using a generalized least-squares regression model. A set of predictive equations for estimating the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year peak streamflows was developed for each streamflow analysis region from peak-streamflow magnitudes and physical and climatic basin characteristics. These equations may be used for unregulated streams without flow diversions, dams, periodically releasing glacial impoundments, or other streamflow conditions not correlated to basin characteristics. Basin characteristics should be obtained using methods similar to those used in this report to preserve the statistical integrity of the equations.

Water-Resources Investigations Report↗

Geochemical evidence of groundwater flow paths and the fate and transport of constituents of concern in the alluvial aquifer at Fort Wingate Depot Activity, New Mexico, 2009

As part of an environmental investigation at Fort Wingate Depot Activity, New Mexico, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, interpreted aqueous geochemical concentrations to better understand the groundwater flow paths and the fate and transport of constituents of concern in the alluvial aquifer underlying the study area. The fine-grained nature of the alluvial matrix creates a highly heterogeneous environment, which adds to the difficulty of characterizing the flow of groundwater and the fate of aqueous constituents of concern. The analysis of the groundwater geochemical data collected in October 2009 provides evidence that is used to identify four groundwater flow paths and their extent in the aquifer and indicates the dominant attenuation processes for the constituents of concern. The extent and interaction of groundwater flow paths were delineated by the major ion concentrations and their relations to each other. Four areas of groundwater recharge to the study area were identified based on groundwater elevations, hydrogeologic characteristics, and geochemical and isotopic evidence. One source of recharge enters the study area from the saturated alluvial deposits underlying the South Fork of the Puerco River to the north of the study area. A second source of recharge is shown to originate from a leaky cistern containing production water from the San Andres-Glorieta aquifer. The other two sources of recharge are shown to enter the study area from the south: one from an arroyo valley draining an area to the south and one from hill-front recharge that passes under the reported release of perchlorate and explosive constituents. The spatial extent and interaction of groundwater originating from these various sources along identified flow paths affect the persistence and attenuation of constituents of concern. It was determined that groundwater originating in the area of a former explosives’ wash-out operation and an accidental spill of perchlorate was spatially limited, and that dilution is the primary attenuation process for these constituents. The explosive concentrations of the nitramine 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and the oxidizer perchlorate both support that determination. Unlike RDX and perchlorate, there were no detectable concentrations of trinitrotoluene (TNT) in the aquifer. Based on the chemical nature of TNT and the redox conditions found in the aquifer, it is interpreted that TNT is lost to irreversible sorption and aerobic degradation. Nitrate was ubiquitous in the alluvial groundwater in October 2009. The nitrate concentrations in wells associated with the explosives’ groundwater flow path indicate attenuation primarily through dilution, similar to that of RDX. The origin of nitrate concentrations in the wells located in the Administration Area is uncertain but may have resulted from the leakage of aging clay sewage pipes that service most of the structures within that area or as a relic of a former hydrologic regime in which water from the washout operation migrated across a broader area. Sufficient data do not exist to definitively identify the location(s) of water discharge in this area, but transpiration from near the Administration Area is supported by the geochemical concentrations.

New Mexico↗

Summary of hydrologic and physical properties of rock and soil materials, as analyzed by the hydrologic laboratory of the U.S. Geological Survey, 1948-60

The Hydrologic Laboratory was established in 1948 to serve as the central laboratory for the Ground Water Branch, Water Resources Division, of the U.S. Geological Survey. During the period it has been in existence, numerous samples of rock and soil materials have been analyzed. Analysis data on samples from 42 states and for the period 1948 through 1960 are summarized. The data are presented in a form to allow an easy comparison of the physical and hydrologic properties of many sedimentary, igneous, and metamorphic rock and soil materials. Sedimentary rocks, the principal water-bearing rocks, are discussed in more detail.

Open-File Report↗

Evaluation of the use of reach transmissivity to quantify leakage beneath Levee 31N, Miami-Dade County, Florida

A coupled ground- and surface-water model (MODBRANCH) was developed to estimate ground-water flow beneath Levee 31N in Miami-Dade County, Florida, and to simulate hydrologic conditions in the surrounding area. The study included compilation of data from monitoring stations, measurement of vertical seepage rates in wetlands, and analysis of the hydrogeologic properties of the ground-water aquifer within the study area. In addition, the MODBRANCH code was modified to calculate the exchange between surface-water channels and ground water using a relation based on the concept of reach transmissivity. The modified reach-transmissivity version of the MODBRANCH code was successfully tested on three simple problems with known analytical solutions. It was also tested and determined to function adequately on one field problem that had previously been solved using the unmodified version of the software. The modified version of MODBRANCH was judged to have performed satisfactorily, and it required about 60 percent as many iterations to reach a solution. Additionally, its input parameters are more physically-based and less dependent on model-grid spacing. A model of the Levee 31N area was developed and used with the original and modified versions of MODBRANCH, which produced similar output. The mean annual modeled ground-water heads differed by only 0.02 foot, and the mean annual canal discharge differed by less than 1.0 cubic foot per second. Seepage meters were used to quantify vertical seepage rates in the Everglades wetlands area west of Levee 31N. A comparison between results from the seepage meters and from the computer model indicated substantial differences that seemed to be a result of local variations in the hydraulic properties in the topmost part of the Biscayne aquifer. The transmissivity of the Biscayne aquifer was estimated to be 1,400,000 square feet per day in the study area. The computer model was employed to simulate seepage of ground water beneath Levee 31N. Modeled seepage rates were usually between 100 and 400 cubic feet per day per foot of levee, but extreme values ranged from about -200 to 500 cubic feet per day (positive values indicate eastward seepage beneath the levee). The modeled seepage results were used to develop an algorithm to estimate seepage based on head differential at selected monitoring stations. The algorithm was determined to adequately predict ground-water seepage.

Florida↗

Selenium loading through the Blackfoot River watershed--linking sources to ecosystem

The upper Blackfoot River watershed in southeast Idaho receives drainage from 11 of 16 phosphate mines that have extracted ore from the Phosphoria Formation, three of which are presently active. Toxic effects from selenium (Se), including death of livestock and deformity in aquatic birds, were documented locally in areas where phosphatic shales are exposed ( Piper et al., 2000 ; Presser et al., Chapter 11). Current drainage conditions are leading to Se bioaccumulation at concentrations that pose a risk to fish in the Blackfoot River and its tributaries (Hamilton et al., Chapter 18). A gaging station on the Blackfoot River was re-activated in April 2001 to assess hydrologic conditions and concentration, load, and speciation for Se discharges on a watershed scale. The gaging-station data are considered to represent regional drainage conditions in the upper Blackfoot River water- shed because of its location near the outlet of the watershed and directly upstream of the Blackfoot Reservoir. Watershed discharges for 2001 and 2002 were below minimum hydrologic conditions for the gage as documented by the historical record. Drought emergencies were declared in the area in both 2001 and 2002. Unmonitored diversions for irrigation that routinely take place during the snowmelt season also affected conditions downstream. Annual cycles in Se concentration, load, and selenate (Se 6+ ) reached maxima in the spring during the period of maximum flow at the gaging station. Thirty-seven to 44% of annual flow occurred dur- ing the three-month high-flow season (April through June) in 2001 and 56% of annual flow occurred during that time period in 2002. Extrapolation from historical hydrographs for average and wet years and a limited data set of regional Se concentrations for 2001 and 2002 indicated potential for a 3.6- to 7.4-fold increase in Se loading because of increased seasonal flows in the Blackfoot River watershed. Supplementation data indicate that: (a) the difference between total Se and dissolved Se, as a measure of the contribution of particulate Se, was < 10% except at the peak of con- centration when total Se was 18% more than dissolved Se; (b) selenite (Se 4+ ) represented less than 10% of the dissolved species during all months of 2001; and (c) dissolved Se was approximately a 50:50 mixture of selenate and organic selenide (operationally defined Se 2- ) during summer 2001 (June through August). Ecological risk based on regional Se drainage occurred during both the high- and low-flow seasons. Seventy to 83% of the Se load occurred during the high-flow season. During early May of both years, dissolved-Se concentrations exceeded the criterion for the protection of aquatic life and the ecological threshold of 5 gL 1 Se at which sub- stantive risk occurs. During the majority of the three-month high-flow season, dissolved- Se concentrations exceeded the 2 gL 1 Se concern level for aquatic biota. The Se concentration in suspended material during high flow in 2002 was within the range of marginal risk to aquatic life (2-4 gg 1 Se, dry weight). Selenate was the major species during peak flows, with both selenate and organic selenide being major species during relatively low-flow periods in summer. A change in speciation to reduced Se may indicate elevated biotic productivity during summer months and could result in enhanced Se uptake in food webs. In addition to the magnitude of regional Se release in the Blackfoot River watershed, Se concentrations in individual source drains and waste-rock seeps, and those predicted by experimental column leaching of proposed mining overburden materials, also indicate that drainage options that currently meet existing demands for phosphate mining cause eco- logical risk thresholds to be exceeded. At times, the drinking-water Se standard (50 g L 1 Se) and the criterion for hazardous Se waste (1000 L -1 Se) ( US Department of the Interior, 1998 ; US Environmental Protection Agency, 1987 ) are also exceeded. For water-years 2001 and 2002, seasonal increased input of water in the mining area resulted in increased Se transport, suggesting a mechanism of contamination that involves a significant Se reservoir. Hence, recognition and monitoring of Se loading to the envi- ronment on a mass balance basis (i.e. inputs, fluxes and storage within environmental media, and outputs) are essential to evaluating how to control Se concentrations within environmentally protective ranges ( Presser and Piper, 1998 ). In areas where release of Se to aquatic systems is anticipated as a product of future expansion of phosphate mining, continuous monitoring of flow and development of seasonal Se loading patterns would help to model watersheds in terms of sources, flow periods, and environmental-Se con- centrations that most influence bioavailability. These data, in turn, could be linked to Se- bioaccumulation models specific to food webs and vulnerable species of the impacted areas to accurately project ecological effects. Gaging at this site on the Blackfoot River is planned to continue in order to establish a long-term (>10 year) record of hydrologic conditions.

Idaho↗

Five hydrologic and landscape databases for selected National Wildlife Refuges in the Southeastern United States

This report serves as metadata and a user guide for five out of six hydrologic and landscape databases developed by the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, to describe data-collection, data-reduction, and data-analysis methods used to construct the databases and provides statistical and graphical descriptions of the databases. Six hydrologic and landscape databases were developed: (1) the Cache River and White River National Wildlife Refuges (NWRs) and contributing watersheds in Arkansas, Missouri, and Oklahoma, (2) the Cahaba River NWR and contributing watersheds in Alabama, (3) the Caloosahatchee and J.N. “Ding” Darling NWRs and contributing watersheds in Florida, (4) the Clarks River NWR and contributing watersheds in Kentucky, Tennessee, and Mississippi, (5) the Lower Suwannee NWR and contributing watersheds in Georgia and Florida, and (6) the Okefenokee NWR and contributing watersheds in Georgia and Florida. Each database is composed of a set of ASCII files, Microsoft Access files, and Microsoft Excel files. The databases were developed as an assessment and evaluation tool for use in examining NWR-specific hydrologic patterns and trends as related to water availability and water quality for NWR ecosystems, habitats, and target species. The databases include hydrologic time-series data, summary statistics on landscape and hydrologic time-series data, and hydroecological metrics that can be used to assess NWR hydrologic conditions and the availability of aquatic and riparian habitat. Landscape data that describe the NWR physiographic setting and the locations of hydrologic data-collection stations were compiled and mapped. Categories of landscape data include land cover, soil hydrologic characteristics, physiographic features, geographic and hydrographic boundaries, hydrographic features, and regional runoff estimates. The geographic extent of each database covers an area within which human activities, climatic variation, and hydrologic processes can potentially affect the hydrologic regime of the NWRs and adjacent areas. The hydrologic and landscape database for the Cache and White River NWRs and contributing watersheds in Arkansas, Missouri, and Oklahoma has been described and documented in detail (Buell and others, 2012). This report serves as a companion to the Buell and others (2012) report to describe and document the five subsequent hydrologic and landscape databases that were developed: Chapter A—the Cahaba River NWR and contributing watersheds in Alabama, Chapter B—the Caloosahatchee and J.N. “Ding” Darling NWRs and contributing watersheds in Florida, Chapter C—the Clarks River NWR and contributing watersheds in Kentucky, Tennessee, and Mississippi, Chapter D—the Lower Suwannee NWR and contributing watersheds in Georgia and Florida, and Chapter E—the Okefenokee NWR and contributing watersheds in Georgia and Florida.

Alabama, Arkansas, Florida, Georgia, Kentucky, Mis↗

Hydrology of the coastal lowlands aquifer system in parts of Alabama, Florida, Louisiana, and Mississippi

Existing data on water levels, water use, water quality, and aquifer properties were used to construct a multilayer digital model to simulate flow in the aquifer system. The report describes the geohydrologic framework of the aquifer system, and the development, calibration, and sensitivity analysis of the ground-water-flow model, but it is primarily focused on the results of the simulations that show the natural flow of ground water throughout the regional aquifer system and the changes from the natural flow caused by development of ground-water supplies.

Alabama, Florida, Louisiana, Mississippi↗

Implications of fire-induced evapotranspiration shifts for recharge-runoff generation and vegetation conversion in the western United States

Wildfire has been shown to increase, decrease, or have no detectable effect on actual evapotranspiration (ETa) fluxes in the western United States. Where disturbance-induced shifts are significant, source-water hydrology may be impacted as ETa constitutes the largest outgoing water flux in much of the arid West. We conducted pixel-scale analysis of 30-m ETa data and various meteorologic and landscape variables at 13 burn scars to understand how wildfire disturbance impacted hillslope-to-burn scar-scale hydrology and vegetation conversion. Significant fire-induced ETa reductions (between approximately −15 to −50%) were detected at nine burn scars through the tenth post-fire year, while ETa recovery rate varied substantially by ecoregion and pre-fire vegetation type. Along elevation gradients, both climate and land disturbance influenced the location of runoff/recharge generation zones, and more net water was generated from a snow-dominated burn scar in dry post-fire years than in wet pre-fire years. However, especially in arid locations where ETa is water-limited, compensatory ETa pathways may be more likely to dampen fire effects on total basin water yield where intact vegetation is located between the disturbance footprint and the basin outlet. Relationships between post-fire ETa shifts and early-successional vegetation conversion were also tracked. The majority of burn scars with significant fire-induced ETa reductions experienced conversion patterns typical of the western United States following stand-replacing disturbance, with forests converting to shrub/scrub and/or grassland/herbaceous cover through at least the end of the study period (eight to 15 years depending on date of the fire event). This could have important implications for high-elevation, snow-dominated watersheds – some of the most critical source water areas - as previous research indicates that wildfire activity is moving upslope and into vegetation communities that have not evolved to withstand fire. Finally, we show that much of the Colorado River Basin’s high-yield source water areas are vulnerable to the fire-induced ETa reductions and vegetation conversion observed herein. As such, water managers in the Colorado River Basin can anticipate changes in burn scar hydrology and snowpack mechanics following fire disturbance.

Journal of Hydrology X↗

Selecting the optimal fine-scale historical climate data for assessing current and future hydrological conditions

High-resolution historical climate grids are readily available and frequently used as inputs for a wide range of regional management and risk assessments, including water supply, ecological processes, and as baseline for climate change impact studies that compare them to future projected conditions. Because historical gridded climates are produced using various methods, their portrayal of landscape conditions differ, which becomes a source of uncertainty when they are applied to subsequent analyses. Here we tested the range of values from five gridded climate datasets. We compared their values to observations from 1231 weather stations, first using each dataset’s native scale, and then after each was rescaled to 270-m resolution. We inputted the downscaled grids to a mechanistic hydrology model and assessed the spatial results of six hydrological variables across California, in 10 ecoregions and 11 large watersheds in the Sierra Nevada. PRISM was most accurate for precipitation, ClimateNA for maximum temperature, and TopoWx for minimum temperature. The single most accurate dataset overall was PRISM due to the best performance for precipitation and low air temperature errors. Hydrological differences ranged up to 70% of the average monthly streamflow with an average of 35% disagreement for all months derived from different historical climate maps. Large differences in minimum air temperature data produced differences in modeled actual evapotranspiration, snowpack, and streamflow. Areas with the highest variability in climate data, including the Sierra Nevada and Klamath Mountains ecoregions, also had the largest spread for snow water equivalent, recharge, and runoff.

Journal of Hydrometeorology↗

Hydrogeochemical investigations in the Osgood Mountains, north-central Nevada

Field investigations performed in the Osgood Mountains during the summers of 1999 and 2000 were designed to test methods of combining geologic, hydrologic, and geochemical investigations. The goals were to develop a more thorough understanding of the movement of water through the study area and to understand the water-rock reactions that may occur along flow paths. The Osgood Mountains were chosen for study because they represent a well-defined geologic system, based on existing and new field data. New work in the area focused on gathering more data about fractures, faults, and joints and on collecting water samples to evaluate the role of geologic structures on hydrologic and geochemical properties of the ground-water/surface-water system. Chemical methods employed in the study included measuring traditional field parameters (e.g., pH, temperature, conductivity, dissolved oxygen) as well as Fe2+ and collecting a variety of samples that were preserved for later laboratory analysis. Hydrologic methods included closely spaced evaluations of substream hydraulic head to define ground-water discharge and recharge zones as well as some measurements of stream discharge. Geologic investigations focused on the locations and orientations of fractures and kinematic indicators of slip observable in outcrops.

Nevada↗

An intercomparison of DOC estimated from fDOM sensors in wildfire affected streams of the western United States

Wildfires in the western United States (US) have been demonstrated to affect water quality, including dissolved organic carbon (DOC), in streams. Elevated post-wildfire DOC concentration poses a potential risk to drinking water treatment systems. In-stream measurements of fluorescent dissolved organic matter (fDOM), a proxy for DOC, have shown potential to detect dynamic changes in DOC. High frequency monitoring of water temperature, turbidity, and fDOM was used in conjunction with discrete sampling during targeted storm events and at fixed intervals to estimate DOC in five western US streams following wildfires in 2020 and 2021 with the objective to characterise and compare responses to wildfire among sites. The elevated turbidity conditions typical after wildfire presented a challenge to fDOM measurements and there was a need to identify appropriate turbidity corrections at burned sites. A combination of established and novel methods corrected fDOM concentrations for turbidity effects up to 800 Formazin nephelometric units (FNU). Pre-wildfire high frequency water quality data in adjacent burned and unburned watersheds allowed for separation of climate effects on DOC at one of the sites. Hydrology, climate and landcover were more important drivers of post-wildfire DOC yield than wildfire characteristics. Seasonal patterns of DOC were unchanged by wildfire in snowmelt-driven watersheds. Large, transient spikes in DOC concentration following frontal and convective storms were observed post-wildfire at all burned sites, but not at the unburned site. These spikes often exceeded operational thresholds for drinking water treatment. This study highlights the ability to develop high frequency DOC estimates in surface waters up to 800 FNU using fDOM sensors and targeted storm sampling and emphasises the value of high frequency pre-wildfire data in adjacent burned and unburned watersheds for separating climate and wildfire effects.

California, Colorado, Montana, Oregon↗

Beavers in the Tualatin River Basin, northwestern Oregon

Growing interest in beaver-assisted restoration in the Tualatin River Basin of northwestern Oregon motivated a series of studies by the U.S. Geological Survey to assess the capacity of the stream network to support beaver dams and to evaluate the effects of beaver dams and ponds on urban streams. This multichapter volume describes the data collection from 2016–17 and the findings of these studies, which were done in partnership with Clean Water Services. Chapter A documents the locations of beaver dams in the Tualatin River Basin and how many beaver dams the stream network could support with existing and improved riparian vegetation. Beaver dam capacity was estimated by modifying existing tools to account for the low gradient of many streams in the Tualatin River Basin. Chapter B describes the effects of beaver dams and ponds on hydrologic and hydraulic responses of storm flows. Hydrologic and hydraulic responses for two urban stream reaches were compared with and without beaver dams and ponds and for a range of streamflow conditions using two-dimensional hydraulic models. Chapter C characterizes the effects of beaver dams and ponds on the transport and deposition of suspended sediment. Continuous turbidity, discrete suspended-sediment samples, and streamflow measurements collected during storms and base-flow periods were used to assess: (1) suspended-sediment loads upstream and downstream from two beaver-affected reaches, and (2) seasonal and longitudinal turbidity patterns. Chapter D describes the effects of beaver dams and ponds on longitudinal, spatial, and seasonal water-quality patterns. Continuous and synoptic water-quality data were collected along urban stream reaches, and net ecosystem production was calculated for two beaver-affected reaches. The findings of these studies illustrate that the effects of beaver dams and ponds on hydrology, hydraulics, suspended-sediment transport and deposition, and water quality are dependent on the characteristics of a stream reach (for example, channel gradient, groundwater exchange, and riparian vegetation) and the characteristics of beaver dams and ponds along that reach. This information can be used to consider the implications of beaver-assisted restoration in the Tualatin River Basin and the effects of beaver dams and ponds in urban streams.

Oregon↗

Hydrologic influences on water-level changes in the Eastern Snake River Plain aquifer at and near the Idaho National Laboratory, Idaho, 1949-2014

The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, has maintained a water-level monitoring program at the Idaho National Laboratory (INL) since 1949 to systematically measure water levels to provide long-term information on groundwater recharge, discharge, movement, and storage in the eastern Snake River Plain (ESRP) aquifer. During 2014, water levels in the ESRP aquifer reached all-time lows for the period of record, prompting this study to assess the effect that future water-level declines may have on pumps and wells. Water-level data were compared with pump-setting depth to determine the hydraulic head above the current pump setting. Additionally, geophysical logs were examined to address changes in well productivity with water-level declines. Furthermore, hydrologic factors that affect water levels in different areas of the INL were evaluated to help understand why water-level changes occur. Review of pump intake placement and 2014 water-level data indicates that 40 wells completed within the ESRP aquifer at the INL have 20 feet (ft) or less of head above the pump. Nine of the these wells are located in the northeastern and northwestern areas of the INL where recharge is predominantly affected by irrigation, wet and dry cycles of precipitation, and flow in the Big Lost River. Water levels in northeastern and northwestern wells generally show water-level fluctuations of as much as 4.5 ft seasonally and show declines as much as 25 ft during the past 14 years. In the southeastern area of the INL, seven wells were identified as having less than 20 ft of water remaining above the pump. Most of the wells in the southeast show less decline over the period of record compared with wells in the northeast; the smaller declines are probably attributable to less groundwater withdrawal from pumping of wells for irrigation. In addition, most of the southeastern wells show only about a 1&ndash;2 ft fluctuation seasonally because they are less influenced by groundwater withdrawals for irrigation. In the southwestern area of the INL, 24 wells were identified as having less than 20 ft of water remaining above the pump. Wells in the southwest also only show small 1&ndash;2 ft fluctuations seasonally because of a lack of irrigation influence. Wells show larger fluctuation in water levels closer to the Big Lost River and fluctuate in response to wet and dry cycles of recharge to the Big Lost River. Geophysical logs indicate that most of the wells evaluated will maintain their current production until the water level declines to the depth of the pump. A few of the wells may become less productive once the water level gets to within about 5 ft from the top of the pump. Wells most susceptible to future drought cycles are those in the northeastern and northwestern areas of the INL.

Idaho↗

Hydrologic data for urban studies in the San Antonio, Texas metropolitan area, 1976

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. These studies are now in progress in Austin, Dallas, Dallas County, Fort Worth, Houston, and San Antonio. The Geological Survey, in cooperation with the Texas Department of Water Resources, expanded the existing streamflow network in the San Antonio metropolitan area in May 1968 to begin urban hydrology studies in this area. In September 1968, the program was further expanded to include the collection of water-quality data.

Texas↗

Hydrology and simulation of ground-water flow in the Aguadilla to Rio Camuy area, Puerto Rico

The aquifers of the Aguadilla to Rio Camuy area, in the northwestern part of Puerto Rico, are the least developed of those on the north coast, and relatively little information is available concerning the ground-water system. The present study, which was part of a comprehensive appraisal of the ground-water resources of the North Coast Province, attempts to interpret the hydrology of the area within the constraints of available data. The study area consists of an uplifted rolling plain that is 200 to 400 feet above sea level and a heavily forested, karst upland. The only major streams in the area are the Rfo Camuy and the Rio Guajataca. Most water used in the area is obtained from Lago de Guajataca, just south of the study area, and ground-water use is minimal (less than 5 million gallons per day). Sedimentary rocks of Tertiary age, mainly limestone and calcareous clays, comprise the aquifers of the Aguadilla to Rio Camuy area. The rocks generally dip from 4 to 7 degrees to the north, and the total sedimentary rock sequence may be as much as 6,000 feet thick near the Atlantic coast. Baseflows for the Rio Camuy are 58 cubic feet per second near Bayaney and 72 cubic feet per second near Hatillo. The ground-water discharge to the Rio Camuy between these stations is estimated to be 15 cubic feet per second, or 2.6 cubic feet per second per linear mile. The flow of the Rio Guajataca is regulated by the Guajataca Dam at Lago de Guajataca. Ground-water discharge to the Rio Guajataca between the dam and the coast is estimated to be about 17 cubic feet per.second, based on the average ground-water discharge per linear mile estimated for the Rio Camuy. Both water-table and artesian aquifers are present in the Aguadilla to Rio Camuy area; how-ever, most ground water occurs within the watertable aquifer, which was the primary focus of this study. The top of the confining unit, below the water-table aquifer, generally is within the unnamed upper member of the Cibao Formation; however, it is within the Los Puertos Formation in the eastern part of the study area. The water-table aquifer primarily is composed of rocks of the Aymam6n Limestone and the Los Puertos Formation. The estimated saturated thickness of the water-table aquifer ranges from zero at the southern limit of the aquifer to more than 600 feet south of Isabela. Hydraulic conductivity of the Aymam6n Limestone, based on specific-capacity test data for seven wells, ranges from about 1 to about 25 feet per day and averages 7.5 feet per day. Hydraulic conductivity of the Los Puertos Formation, based on specific-capacity test data for four wells, generally was less than 7 feet. per day. The average hydraulic-conductivity value for both the Aymam6n Limestone and the Los Puertos Formation, based on specific-capacity test data, is estimated to be about 6.0 feet per day. These hydraulic-conductivity values are much less than average values for the water-table aquifer reported for other parts of the North Coast Province. Transmissivity values, based on the average hydraulic-conductivity value for the aquifer derived from specific-capacity tests, range from zero to about 4,000 feet squared per day; however, these values were adjusted upward during model calibration. Ground water generally moves from the highlands in the south toward the sea to the north and west, and locally, to streams. A major groundwater divide extends from the southeastern corner of the study area to the northwest, and separates flow north and east into the study area from flow to the southwest toward the Rio Culebrinas. Nearly all recharge to the aquifer is from infiltration of rainfall into the karst uplands. Discharge from the aquifer primarily occurs as leakage to streams and to the sea, and to a lesser degree as flow to wells. A two-layer, three-dimensional, steady-state, numerical model was constructed to simulateground-water flow in the water-table aquifer between Aguadilla and the R/o Camuy area. A basic a

Water-Resources Investigations Report↗

Flood-inundation maps for the Flatrock River at Columbus, Indiana, 2012

Digital flood-inundation maps for a 5-mile reach of the Flatrock River on the western side of Columbus, Indiana, from County Road 400N to the river mouth at the confluence with Driftwood River, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ and the Federal Flood Inundation Mapper Web site at http://wim.usgs.gov/FIMI/FloodInundationMapper.html, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Flatrock River at Columbus (station number 03363900). Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service, which also presents the USGS data, at http:/water.weather.gov/ahps/. Flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relation at the Flatrock River streamgage, high-water marks that were surveyed following the flood of June 7, 2008, and water-surface profiles from the current flood-insurance study for the City of Columbus. The hydraulic model was then used to compute 12 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from 9 ft or near bankfull to 20 ft, which exceeds the stages that correspond to both the estimated 0.2-percent annual exceedance probability flood (500-year recurrence interval flood) and the maximum recorded peak flow. The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from Light Detection and Ranging (LiDAR) data having a 0.37 ft vertical accuracy and 3.9 ft horizontal resolution) to delineate the area flooded at each water level. The availability of these maps on the USGS Federal Flood Inundation Mapper Web site, along with Internet information regarding current stage from the USGS streamgage, will provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, as well as for post-flood recovery efforts.

Indiana↗