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At least 1,135 records · Page 63Linked to original sources
USGS2023

Simulation of groundwater flow at the former Badger Army Ammunition Plant, Sauk County, Wisconsin

To help support remedial efforts at the former Badger Army Ammunition Plant the U.S. Geological Survey built and calibrated a transient groundwater flow model using the Newton Raphson formulation (MODFLOW–NWT) of the U.S. Geological Survey’s modular three-dimensional finite-difference code. The model simulates the groundwater flow system at the site from 1984 to 2020. The former Badger Army Ammunition Plant is a 7,275-acre site in Sauk County, Wisconsin. The plant produced smokeless gunpower and solid rocket propellent as munitions components. Peak production periods were during World War II, the Korean War, and the Vietnam War. Subsequent groundwater contamination investigations have found four plumes at the site. A health risk assessment identified at least one contaminant of concern for human health risk present in three of the plumes: the propellant burning ground plume, the deterrent burning ground plume, and the central plume. A cooperative study began between the U.S. Army Environmental Command and U.S. Geological Survey to better understand the groundwater flow system at the former Badger Army Ammunition Plant. Field data, including aquifer tests, streamflow measurements, continuous groundwater elevations, and groundwater gradients with the Wisconsin River were collected and used to inform and calibrate the groundwater flow model. The model was used to assess the variability of the groundwater system over the study period, the components of the groundwater budget, and groundwater flow directions from identified source areas towards the Wisconsin River. Model performance assessment focused on using particle tracking to compare groundwater flowpaths that originate in the contaminant source areas to the observed plume footprints. This focus on plume behavior geometry should help constrain the advective component of a future groundwater transport model of the site.

Wisconsin↗
USGS1984

Potentiometric map of the Paleozoic aquifer in northeastern Mississippi, November and December 1982

This potentiometric map is the second map of the Gordo aquifer in a series of maps prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources , Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. The potentiometric surface of the Gordo aquifer slopes generally to the west away from the outcrop area and it is marked by large ground-water cones of depression in the Tupelo and Columbus areas. Water levels in or near the outcrop of the Gordo aquifer show little long-term change. Heavy withdrawals in the downdip area have caused water-level declines of about 2 feet per year since 1978 in much of the confined part of the aquifer. The water-level decline in the Tupelo area has averaged about 5 feet per year since 1966; however, there has been water-level rise at the center of the cone of depression as a result of a change in the distribution of pumping. (USGS)

Water-Resources Investigations Report↗
USGS1994

Relation of stream quality to streamflow, and estimated loads of selected water-quality constituents in the James and Rappahannock rivers near the fall line of Virginia, July 1988 through June 1990

This report presents the results of a study by the U.S. Geological Survey, in cooperation with the Virginia Department of Environmental Quality-- Division of Intergovernmental Coordination to monitor and estimate loads of selected nutrients and suspended solids discharged to Chesapeake Bay from two major tributaries in Virginia. From July 1988 through June 1990, monitoring consisted of collecting depth-integrated, cross-sectional samples from the James and Rappahannock Rivers during storm- flow conditions and at scheduled intervals. Water- quality constituents that were monitored included total suspended solids (residue, total at 105 degrees Celsius), dissolved nitrite plus nitrate, dissolved ammonia, total Kjeldahl nitrogen (ammonia plus organic), total nitrogen, total phosphorus, dissolved orthopohosphorus, total organic carbon, and dissolved silica. Daily mean load estimates of each constituent were computed by month, using a seven-parameter log-linear-regression model that uses variables of time, discharge, and seasonality. Water-quality data and constituent- load estimates are included in the report in tabular and graphic form. The data and load estimates provided in this report will be used to calibrate the computer modeling efforts of the Chesapeake Bay region, evaluate the water quality of the Bay and the major effects on the water quality, and assess the results of best-management practices in Virginia.

Water-Resources Investigations Report↗
USGS1999

Sediment accumulation and water volume in Loch Raven Reservoir, Baltimore County, Maryland

Baltimore City and its metropolitan area are supplied with water from three reservoirs, Liberty Reservoir, Prettyboy Reservoir, and Loch Raven Reservoir. Prettyboy and Loch Raven Reservoirs are located on the Gunpowder Falls (figure 1). The many uses of the reservoir system necessitate coordination and communication among resource managers. The 1996 Amendment to the Safe Drinking Water Act require States to complete source-water assessments for public drinking-water supplies. As part of an ongoing effort to provide safe drinking water and as a direct result of these laws, the City of Baltimore and the Maryland Department of the Environment (MDE), in cooperation with other State and local agencies, are studying the Gunpowder Falls Basin and its role as a source of water supply to the Baltimore area. As a part of this study, the U.S. Geological Survey (USGS), in cooperation with the Maryland Geological Survey (MGS), with funding provided by the City of Baltimore and MDE, is examining sediment accumulation in Loch Raven Reservoir. The Baltimore City Department of Public Works periodically determines the amount of water that can be stored in its reservoirs. To make this determination, field crews measure the water depth along predetermined transects or ranges. These transects provide consistent locations where water depth, or bathymetric, measurements can be made. Range surveys are repeated to provide a record of the change in storage capacity due to sediment accumulation over time. Previous bathymetric surveys of Loch Raven Reservoir were performed in 1943, 1961, 1972, and 1985. Errors in data-collection and analysis methods have been assessed and documented (Baltimore City Department of Public Works, 1989). Few comparisons can be made among survey results because of changing data-collection techniques and analysis methods.

Water-Resources Investigations Report↗
USGS1996

Occurrence of selenium and mercury in surface water, Wind River Indian Reservation, Wyoming, 1995

Surface-water samples for chemical analyses were collected during May and August 1995 from 13 sites in an irrigated area of the Wind River Federal Irrigation Project, Wind River Indian Reservation, Wyoming. Sites included irrigation drains, ponds, and streams in an irrigated area partially underlain by seleniferous geologic materials described as having the potential to support vegetation that may be toxic to animals. Samples were analyzed for dissolved selenium, mercury, and other inorganic constituents. The study was done in cooperation with the Shoshone Tribe and the Northern Arapaho Tribe. Six samples analyzed from the May sampling period had dissolved selenium concentrations greater than the aquatic-life chronic criterion of 5 μg/L (micrograms per liter) established by the U.S. Environmental Protection Agency (USEPA). The largest dissolved selenium concentration (49 μg/L) exceeded the aquatic-life acute criterion of 20 μg/L established by the USEPA. Selenium concentrations in all 12 samples collected during the August sampling period were less than the laboratory minimum reporting level of 5 μg/L. The Goose Pond Drain site was dry in August. The dissolved solids concentrations were larger in samples collected in May than in August from all but two sites. The large dissolved selenium concentrations in the May samples, collected prior to the start of the irrigation season, were associated with large dissolved solids concentrations. Dissolved mercury concentrations were less than the minimum reporting level of 0.1 jig/L for 24 of the 25 samples collected during May and August. One sample collected in May had a concentration of 0.3 μg/L. This concentration was less than the aquatic-life acute criterion of 2.4 μg/L for mercury established by the USEPA.

Wyoming↗
USGS1998

Monitoring of Selected Water-Quality Constituents Near the Freshwater/Saline-Water Interface of the Edwards Aquifer, July 1996-December 1997

The Edwards aquifer is the sole source of water for about 1.3 million people in and near San Antonio, Texas, as well as for ranchers and farmers throughout south-central Texas. Because of the demand for this resource, various studies have been conducted to better understand the Edwards aquifer and how the aquifer reacts to environmental changes and human influences. In July 1996, the U.S. Geological Survey (USGS), in cooperation with the Edwards Aquifer Research and Data Center (EARDC) at Southwest Texas State University (SWTSU) and the Texas Water Development Board (TWDB), began a study to investigate possible changes in water quality of the Edwards aquifer near the freshwater/saline-water interface that might result if drought occurs. The continuing study is part of the USGS National WaterQuality Assessment (NAWQA) Program in south-central Texas. The freshwater/saline-water interface, known locally as the “bad-water line,” marks the beginning of the transition in the aquifer from freshwater (updip) to saline water (downdip). The interface is defined as the 1,000-milligram-per-liter (mg/L) line of equal dissolved solids concentration as delineated by Maclay and others (1980, fig. 7). Water in the freshwater zone of the Edwards aquifer tends to have dissolved solids concentrations of 250 to 300 mg/L (Pavlicek and others, 1987, p. 3). In contrast, water in the saline-water zone of the Edwards aquifer commonly has dissolved solids concentrations greater than 10,000 mg/L, and sample concentrations as large as 232,000 mg/L have been measured (Groschen and Buszka, 1997, p. 21).

Fact Sheet↗
USGS1984

An assessment of cumulative impacts of coal mining on the hydrology in part of the Powder River structural basin, Wyoming: A progress report

The U.S. Geological Survey and the Wyoming Department of Environmental Quality are involved in a cooperative effort to assess the probable cumulative impacts of coal mining on the hydrology of a part of the Powder River Structural Basin in Wyoming. It was assumed that the principal impacts on the ground-water system due to mining will occur in the relatively shallow aquifers which can be grouped into three homogeneous aquifers, namely, the Wyodak coal, the overburden, and the under burden. Emphasis of this report is on the results of analysis of surface-water resources in the Caballo Creek drainage. A surface-water model of the Caballo Creek drainage was developed using the Hydrological Simulation Program-Fortran model to help assess the impacts of mining activities on streamflow. The Caballo Creek drainage was divided into 10 land segments and 6 stream reaches in the modeling process. Three simulation runs show little, if any, change in streamflow between pre- and post-mining conditions and very little change between pre-mining and during-mining conditions. The principal reason for the absence of change is the high infiltration rate used in the model for all three conditions.

Wyoming↗
USGS1985

Percentage change in saturated thickness of the High Plains aquifer, west-central Kansas, 1950 to average 1983-85

Continuing studies are being made in west-central Kansas to provide up-to-date information to aid in the management of groundwater for irrigation. This report, prepared in cooperation with the Western Kansas Groundwater Management District No. 1, presents the fifth in a series of studies that uses a statistical technique, called kriging, to produce hydrologic maps that are used as management tools. Kriging is a statistical technique that was used to interpolate water level altitudes at the center of each 1-square-mile section in the study area based on measured water levels at 165 observation wells. These interpolation altitudes (1,859 in all), along with bedrock surface and base year water table altitudes, were used to prepare a geohydrologic map illustrating percentage change in saturated thickness. Saturated thickness, as used in this report, is the thickness of the High Plains aquifer between the groundwater surface indicated by water table altitudes and the bedrock surface. Because irrigation development in west-central Kansas was minimal prior to 1950, the saturated thickness during 1950 represented a nearly static condition in the aquifer. Thus, the effects of irrigation withdrawalson the volume of water in storage could be related to the decrease or percentage change in saturated thickness of the aquifer from 1950 to average saturated thickness during 1983-85.

Kansas↗
USGS2021

Development of a groundwater-simulation model in the Los Angeles Coastal Plain, Los Angeles County, California

Executive Summary The Los Angeles Coastal Plain (LACP) covers about 580 square miles and is the largest coastal plain of semiarid southern California. The LACP is heavily developed with mostly residential, commercial, and industrial land uses that rely heavily on groundwater for water supply. In 2010, the LACP was home to about 14 percent of California’s population, or about 5.4 million residents. The LACP is also a major commercial and industrial hub with industries including manufacturing, aerospace, entertainment, and tourism. There has been a heavy reliance on groundwater from the LACP for many years. An average of 305,000 acre-feet per year (acre-ft/yr) of groundwater was used annually from the LACP from 1971 to 2015. The need to replenish the groundwater basins within the LACP was recognized as far back as the 1930s, when spreading grounds were first used to replenish groundwater basins and store water underground during times of water surplus to meet demands in times of shortage. Seawater intrusion resulting from freshwater pumping was first observed in the 1940s. As a result, injection of imported water through wells at what is now the West Coast Basin Barrier Project began on an experimental basis in 1951. Managed aquifer recharge from the spreading grounds and barrier wells is now a substantial component of the LACP’s groundwater supply. The average annual recharge from water spreading from 1971 to 2015 was about 120,000 acre-ft/yr, and the average annual injection into the barrier wells was about 33,000 acre-ft/yr. Other inflows include areal recharge, underflow from San Gabriel and San Fernando Valleys, and onshore flow from the ocean. The average annual recharge from these sources was 100,000 acre-feet (acre-ft) from 1971 to 2015. Additionally, cross-boundary flow from Orange County into the western Orange County subareas of the LACP was simulated as 48,000 acre-ft from 1971 to 2015. This study, conducted in cooperation with the Water Replenishment District of Southern California (WRD), involved an assessment of the historical and present status of groundwater resources in the LACP and the development of tools to better understand the groundwater system. These efforts were built upon results from previous studies and incorporate new information and developments in modeling capabilities to provide a more detailed analysis of the aquifer systems. This study includes a comprehensive compilation of geologic and hydrologic data (Chapter A), development of a chronostratigraphic model that provides a detailed description of the LACP aquifer systems (Chapter B), characterization of the groundwater hydrology of the LACP, including a down-hole analysis of grain size using lithologic and geophysical logs (Chapter C), and development and application of the Los Angeles Coastal Plain Groundwater-flow Model (LACPGM) to simulate past groundwater conditions, estimate groundwater-budget components and flow paths, and approximate future groundwater conditions under different scenarios (Chapter D).

California↗
USGS1998

Radium-226 and radium-228 in shallow ground water, southern New Jersey

Concentrations of total radium (the sum of radium-226 and radium-228) and gross alpha-particle activities in drinking water that exceed the U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Levels (MCLs) are known to cause cancer. Results of investigations by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection (NJDEP) indicate that concentrations of total radium in water samples from 33 percent of 170 wells in the Kirkwood-Cohansey aquifer system in southern New Jersey exceeded the MCL of 5 pCi/L (picocuries per liter) (fig. 1). Wells containing water in which concentrations of total radium were greater than the MCL typically are found where the Bridgeton Formation crops out, in or near an agricultural area, where ground water is acidic (pH less than 5), and where nitrate concentrations generally exceed 5 mg/L (milligrams per liter). Leaching of nitrogen, calcium, and magnesium from agricultural chemicals (fertilizer, lime) applied to cropland may increase the mobility of radium in ground water. Gross alphaparticle activities exceeded the USEPA MCL of 15 pCi/L in water from 14 percent of 127 wells. A statistically significant 2:1 ratio between gross alpha-particle activity and concentration of total radium indicates that gross alpha-particle activity can be used as a screening tool to predict the presence of water that may have a high total-radium concentration.

New Jersey↗
USGS2004

Sources of mercury in sediments, water, and fish of the lakes of Whatcom County, Washington

Concerns about mercury (Hg) contamination in Lake Whatcom, Washington, were raised in the late 1990s after a watershed protection survey reported elevated concentrations of Hg in smallmouth bass. The U.S. Geological Survey, the Whatcom County Health Department, and the Washington State Department of Ecology (Ecology) cooperated to develop a study to review existing data and collect new data that would lead to a better understanding of Hg deposition to Lake Whatcom and other lakes in Whatcom County, Washington. A simple atmospheric deposition model was developed that allowed comparisons of the deposition of Hg to the surfaces of each lake. Estimates of Hg deposition derived from the model indicated that the most significant deposition of Hg would have occurred to the lakes north of the City of Bellingham. These lakes were in the primary wind pattern of two municipal waste incinerators. Of all the lakes examined, basin 1 of Lake Whatcom would have been most affected by the Hg emissions from the chlor-alkali plant and the municipal sewage-sludge incinerator in the City of Bellingham. The length-adjusted concentrations of Hg in largemouth and smallmouth bass were not related to estimated deposition rates of Hg to the lakes from local atmospheric sources. Total Hg concentrations in the surface sediments of Lake Whatcom are affected by the sedimentation of fine-grained particles, whereas organic carbon regulates the concentration of methyl-Hg in the surface sediments of the lake. Hg concentrations in dated sediment core samples indicate that increases in Hg sedimentation were largest during the first half of the 20th century. Increases in Hg sedimentation were smaller after the chlor-alkali plant and the incinerators began operating between 1964 and 1984. Analysis of sediments recently deposited in basin 1 of Lake Whatcom, Lake Terrell, and Lake Samish indicates a decrease in Hg sedimentation. Concentrations of Hg in Seattle precipitation and in tributary waters were used to calculate current (2002-03) loadings of Hg to Lake Whatcom. Hg in tributaries contributed 59 percent of the total Hg, whereas non-local atmospheric deposition was estimated to have contributed 41 percent of the 303 grams of Hg entering Lake Whatcom each year. However, these inputs cannot be verified without a better understanding of the sources of sediment to Lake Whatcom.

Scientific Investigations Report↗
USGS2004

Integrated investigations of environmental effects of historical mining in the Basin and Boulder Mining Districts, Boulder River watershed, Jefferson County, Montana

The Boulder River watershed is one of many watersheds in the western United States where historical mining has left a legacy of acid mine drainage and elevated concentrations of potentially toxic trace elements. Abandoned mine lands commonly are located on or affect Federal land. Cleaning up these Federal lands will require substantial investment of resources. As part of a cooperative effort with Federal land-management agencies, the U.S. Geological Survey implemented an Abandoned Mine Lands Initiative in 1997. The goal of the initiative was to use the watershed approach to develop a strategy for gathering and communicating the scientific information needed to formulate effective and cost-efficient remediation of affected lands in a watershed. The watershed approach is based on the premise that contaminated sites that have the most profound effect on water and ecosystem quality within an entire watershed should be identified, characterized, and ranked for remediation. The watershed approach provides an effective means to evaluate the overall status of affected resources and helps to focus remediation at sites where the most benefit will be gained in the watershed. Such a large-scale approach can result in the collection of extensive information on the geology and geochemistry of rocks and sediment, the hydrology and water chemistry of streams and ground water, and the diversity and health of aquatic and terrestrial organisms. During the assessment of the Boulder River watershed, we inventoried historical mines, defined geological conditions, assessed fish habitat, collected and chemically analyzed hundreds of water and sediment samples, conducted toxicity tests, analyzed fish tissue and indicators of physiological malfunction, examined invertebrates and biofilm, and defined hydrological regimes. Land- and resource-management agencies are faced with evaluating risks associated with thousands of potentially harmful mine sites, and this level of effort is not always feasible for every affected watershed. The detailed work described in this report can help Federal land-management agencies decide which characterization efforts would be most useful in characterization of other affected watersheds.

Montana↗
USGS2008

Temporal and spatial variations in precipitation, streamflow, suspended-sediment loads and yields, and land-condition trend analysis at the U.S. Army Piñon Canyon Maneuver Site, Las Animas County, Colorado, 1983 through 2007

In 2007, the U.S. Geological Survey, in cooperation with the U.S. Department of the Army, began an assessment of the spatial and temporal variations in precipitation, streamflow, suspended-sediment loads and yields, changes in land condition, effects of the tributaries on the Purgatoire River and the possible relation of effects from military training to hydrology and land conditions that have occurred at Pinon Canyon Maneuver Site (PCMS) from 1983 through 2007. Data were collected for precipitation (19 stations) and streamflow and sediment load (5 tributary and 2 main-stem Purgatoire River stations) during 1983 through 2007 for various time periods. The five tributary stations were Van Bremer Arroyo near Model, Taylor Arroyo below Rock Crossing, Lockwood Canyon Creek near Thatcher, Red Rock Canyon Creek at the mouth, and Bent Canyon Creek at the mouth. In addition, data were collected at two Purgatoire River stations: Purgatoire River near Thatcher and Purgatoire River at Rock Crossing.

Colorado↗
USGS2026

Urban stormwater treatment using biofiltration—Variable performance across solids, nutrients, major ions, and metals

Urban runoff from streets and parking lots carries pollutants that degrade receiving waters. Green infrastructure, such as biofilters, is increasingly used to treat this runoff by mimicking natural hydrologic processes. The U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District, evaluated a biofilter receiving roadway runoff from an industrial area in Milwaukee, Wisconsin, over a 3-year period (2022–24). Paired inlet and outlet samples were analyzed for changes in runoff volume, peak discharge, and concentrations of solids, nutrients, major ions, and metals. The biofilter reduced runoff volume by 86 percent and peak discharge by 92 percent, with substantial reductions in total suspended solids (99 percent), total phosphorus (86 percent), and particulate metals (greater than 80 percent for most analytes). However, dissolved constituents showed variable performance; dissolved phosphorus and several metals exhibited net export, likely influenced by media composition, redox conditions, and winter road salt inputs. Sodium export, despite stable chloride loads, suggests cation exchange and seasonal release dynamics. These findings highlight limitations of conventional biofilter designs for dissolved pollutants and underscore the need for improved media, vegetation management, and consideration of winter deicing practices.

Wisconsin↗
USGS2003

Streamwater quality at selected sites in the Fraser River basin, Grand County, Colorado, water years 1991-2000

To determine the effect of population growth on streamwater quality in the Fraser River Basin, the U.S. Geological Survey did a study in cooperation with the Grand County Commissioners and the East Grand County Water Quality Board. During water years 1991 through 2000, the study determined that concentrations of un-ionized ammonia and nitrite plus nitrate in the streamwater of the basin are within Colorado State streamwater?quality standards. The study also found that concentrations of chloride are largest at the headwaters and decrease downstream; however, chloride loading in the stream has the opposite relation. Most nutrient loading to the Fraser River happens January through May. Concentrations of ammonia at Fraser River downstream from Vasquez Creek at Winter Park had a downward trend through the period of the study. Nitrite plus nitrate had upward and downward trends at different sites and over different time spans. Orthophosphorus concentrations had upward trends at two sites. In general, the streamwater quality in the Fraser River Basin is good and is not out of compliance with State standards.

Water-Resources Investigations Report↗
USGS2006

Continuous water-quality monitoring and regression analysis to estimate constituent concentrations and loads in the Red River of the North, Fargo, North Dakota, 2003-05

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the Bureau of Reclamation, U.S. Department of the Interior, to estimate water-quality constituent concentrations in the Red River of the North at Fargo, North Dakota. Regression analysis of water-quality data collected in 2003-05 was used to estimate concentrations and loads for alkalinity, dissolved solids, sulfate, chloride, total nitrite plus nitrate, total nitrogen, total phosphorus, and suspended sediment. The explanatory variables examined for regression relation were continuously monitored physical properties of water-streamflow, specific conductance, pH, water temperature, turbidity, and dissolved oxygen. For the conditions observed in 2003-05, streamflow was a significant explanatory variable for all estimated constituents except dissolved solids. pH, water temperature, and dissolved oxygen were not statistically significant explanatory variables for any of the constituents in this study. Specific conductance was a significant explanatory variable for alkalinity, dissolved solids, sulfate, and chloride. Turbidity was a significant explanatory variable for total phosphorus and suspended sediment. For the nutrients, total nitrite plus nitrate, total nitrogen, and total phosphorus, cosine and sine functions of time also were used to explain the seasonality in constituent concentrations. The regression equations were evaluated using common measures of variability, including R2, or the proportion of variability in the estimated constituent explained by the regression equation. R2 values ranged from 0.703 for total nitrogen concentration to 0.990 for dissolved-solids concentration. The regression equations also were evaluated by calculating the median relative percentage difference (RPD) between measured constituent concentration and the constituent concentration estimated by the regression equations. Median RPDs ranged from 1.1 for dissolved solids to 35.2 for total nitrite plus nitrate. Regression equations also were used to estimate daily constituent loads. Load estimates can be used by water-quality managers for comparison of current water-quality conditions to water-quality standards expressed as total maximum daily loads (TMDLs). TMDLs are a measure of the maximum amount of chemical constituents that a water body can receive and still meet established water-quality standards. The peak loads generally occurred in June and July when streamflow also peaked.

North Dakota↗
USGS2011

Potentiometric surface of the Upper Floridan aquifer, west-central Florida, September 2010

This report, prepared by the U.S. Geological Survey in cooperation with the Southwest Florida Water Management District, is part of a semi-annual series of Upper Floridan aquifer potentiometric-surface map reports for west-central Florida. Potentiometric surface maps have been prepared for January 1964, May 1969, May 1971, May 1973, May 1974, and for each May and September since 1975. Water-level data are collected in May and September each year to show the approximate annual low and high water-level conditions, respectively. This map report shows the potentiometric surface of the Upper Floridan aquifer measured in September 2010. The potentiometric surface is an imaginary surface connecting points of equal altitude to which water will rise in tightly-cased wells that tap a confined aquifer system (Lohman, 1979). This map represents water-level conditions near the end of the wet season, when groundwater levels usually are at an annual high and withdrawals for agricultural use typically are low. The cumulative average rainfall of 53.17 inches for west-central Florida (from October 2009 through September 2010) was 0.41 inches above the historical cumulative average of 52.76 inches (Southwest Florida Water Management District, 2010). Historical cumulative averages are calculated from regional rainfall summary reports (1915 to most recent complete calendar year) and are updated monthly by the Southwest Florida Water Management District.

Florida↗
USGS2024

Flood-inundation maps for the Cuyahoga River in and near Independence, Ohio, 2024

Digital flood-inundation maps for a 9.9-mile reach of the Cuyahoga River in and near Independence, Ohio, were created by the U.S. Geological Survey (USGS) in cooperation with the Northeast Ohio Regional Sewer District Board of Trustees. Water-surface profiles were computed for the stream reach by using a one-dimensional steady-state step-backwater model. The model was calibrated to the current (2024) stage-streamflow relation (rating curve 43.0) for the USGS streamgage 04208000, Cuyahoga River at Independence, Ohio. The resulting hydraulic model was then used to compute 13 water-surface profiles for water levels (flood stages) ranging from 14.00 to 26.00 feet. The flood stages range from “action stage” to above “major flood stage” as reported by the National Weather Service. The simulated water-surface profiles were then used in combination with a digital elevation model derived from light detection and ranging data to map the inundated areas associated with each flood profile. The flood-inundation maps and the supporting hydraulic model produced by this study can be used by emergency managers and local officials to assess flood mitigation strategies and to define flood hazard areas to protect life and property, to coordinate flood response activities such as evacuations and road closures, and to aid postflood recovery efforts.

Ohio↗