Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Water Resources Management”

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 775 records · Page 43Linked to original sources

Water-use analysis program for the Neshaminy Creek basin, Bucks and Montgomery counties, Pennsylvania

A water-use analysis computer program was developed for the Neshaminy Creek Basin to assist in managing and allocating water resources in the basin. The program was developed for IBM-compatible personal computers. Basin analysis and the methodologies developed for the Neshaminy Creek Basin can be transferred to other watersheds. The development and structure of the water-use analysis program is documented in this report. The report also serves as a user's guide. The program uses common relational database-management software that allows for water use-data input, editing, updating and output and can be used to generate a watershed water-use analysis report. The watershed-analysis report lists summations of public-supply well withdrawals; a combination of industrial, commercial, institutional, and ground-water irrigation well withdrawals; spray irrigation systems; a combination of public, industrial, and private surface-water withdrawals; wastewater-tratement-facility dishcarges; estimates of aggregate domestic ground-water withdrawals on an areal basin or subbasin basis; imports and exports of wastewater across basin or subbasin divides; imports and exports of public water supplies across basin or subbasin divides; estimates of evaporative loss and consumptive loss from produce incorporation; industrial septic-system discharges to ground water; and ground-water well-permit allocations.

Pennsylvania↗

Summary of U.S. Geological Survey investigations and hydrologic conditions in the Southwest Florida Water Management District for 1978

This report summarizes water-resources investigations in the Southwest Florida Water Management District performed by the U.S. Geological Survey, Water Resources Division, for fiscal year 1978. The investigations are part of the Federal program of appraising the nation 's water resources. The cooperative program for fiscal year 1978 included 37 interpretive investigations. Abstracts of 30 reports released during 1978 and a bibliography of reports released since 1933 are included. The hydrologic setting of southwest Florida and discussions of surface-water, ground-water, and quality-of-water conditions are given. Hydrologic conditions in southwest Florida are described and illustrated by hydrographs of selected surface-water, ground-water and lake-stage data collection sites. In addition, summaries of water-use data and data on the regional observation monitor-well program are provided. (Kosco-USGS)

Florida↗

Landscape-scale drivers of endangered Cape Sable Seaside Sparrow (Ammospiza maritima mirabilis) presence using an ensemble modeling approach

The Florida Everglades is a vast and iconic wetland ecosystem in the southern United States that has undergone dramatic changes from habitat degradation, development encroachment, and water impoundment. Starting in the past few decades, large restoration projects have been undertaken to restore the landscape, including improving conditions for threatened and imperiled taxa. One focus of restoration has been the marl prairie ecosystem, where the federally endangered Cape Sable Seaside Sparrow ( Ammospiza maritima mirabilis ; CSSS) resides. The CSSS is endemic to the Everglades where populations have been steadily declining, signaling the importance of decision support tools for natural resource managers for evaluating water management and restoration scenarios. Here we developed an ensemble logistic regression, combining a frequentist and Bayesian approach, to model CSSS presence and measure how environmental factors such as hydrometrics, fire occurrence, and vegetation structure impact CSSS habitat suitability. This is the first analysis to quantitatively assess the interdependent relationships between a broad range of environmental factors and CSSS presence across the landscape. Our results show that the probability of CSSS presence was highest in areas with dry conditions, hydroperiods between 80 and 120 days, percentages of canopy cover and woody vegetation less than 10%, and more than six years post-fire where 75% or more of the area was burned. Because the frequentist and Bayesian models had nearly identical spatial outputs with the Bayesian model having slightly higher validation metrics, we used the Bayesian approach as our final model (EverSparrow). The results from our analysis can provide a valuable decision support tool as natural resource managers work to restore the Everglades landscape.

Florida↗

Water Resources Data, North Dakota, Water Year 2000. Volume 2. Ground Water

This edition of the annual hydrologic data report of North Dakota is one of a series of annual reports that document hydrologic data collected from the U.S. Geological Survey's collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by Federal, State, local agencies, and the private sector for developing and managing land and water resources in North Dakota.

Water Data Report↗

Water Resources Data, North Dakota, Water Year 1998. Volume 2. Ground Water

This edition of the annual hydrologic data report of North Dakota is one of a series of annual reports that document hydrologic data collected from the U.S. Geological Survey's collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by Federal, State, local agencies, and the private sector for developing and managing land and water resources in North Dakota.

Water Data Report↗

Helicopter electromagnetic and magnetic geophysical survey data, portions of the North Platte and South Platte Natural Resources Districts, western Nebraska, May 2009

This report is a release of digital data from a helicopter electromagnetic and magnetic survey that was conducted during June 2009 in areas of western Nebraska as part of a joint hydrologic study by the North Platte Natural Resource District (NRD), South Platte NRD, and U.S. Geological Survey (USGS). Flight lines for the survey totaled 937 line kilometers (582 line miles). The objective of the contracted survey, conducted by Fugro Airborne, Ltd., is to improve the understanding of the relation between surface-water and groundwater systems critical to developing groundwater models used in management programs for water resources. A unique aspect of the survey is the flight line layout. One set of flight lines was flown in a zig-zag pattern extending along the length of the previously collected airborne data. The success of this survey design depended on a well-understood regional hydrogeologic framework and model developed by the Cooperative Hydrologic Study of the Platte River Basin and the airborne geophysical data collected in 2008. Resistivity variations along lines could be related to this framework. In addition to these lines, more traditional surveys consisting of parallel flight lines, separated by about 400 meters were carried out for three blocks in the North Platte NRD, the South Platte NRD and in the area of Crescent Lakes. These surveys helped to establish the spatial variations of the resistivity of hydrostratigraphic units. An additional survey was flown over the Crescent Lake area. The objective of this survey, funded by the USGS Office of Groundwater, was to map shallow hydrogeologic features of the southwestern part of the Sand Hills that contain a mix of fresh to saline lakes.

Open-File Report↗

Hybrid-optimization algorithm for the management of a conjunctive-use project and well field design

Hi-Desert Water District (HDWD), the primary water-management agency in the Warren Groundwater Basin, California, plans to construct a waste water treatment plant to reduce future septic-tank effluent from reaching the groundwater system. The treated waste water will be reclaimed by recharging the groundwater basin via recharge ponds as part of a larger conjunctive-use strategy. HDWD wishes to identify the least-cost conjunctiveuse strategies for managing imported surface water, reclaimed water, and local groundwater. As formulated, the mixed-integer nonlinear programming (MINLP) groundwater-management problem seeks to minimize water delivery costs subject to constraints including potential locations of the new pumping wells, California State regulations, groundwater-level constraints, water-supply demand, available imported water, and pump/recharge capacities. In this study, a hybrid-optimization algorithm, which couples a genetic algorithm and successive-linear programming, is developed to solve the MINLP problem. The algorithm was tested by comparing results to the enumerative solution for a simplified version of the HDWD groundwater-management problem. The results indicate that the hybrid-optimization algorithm can identify the global optimum. The hybrid-optimization algorithm is then applied to solve a complex groundwater-management problem. Sensitivity analyses were also performed to assess the impact of varying the new recharge pond orientation, varying the mixing ratio of reclaimed water and pumped water, and varying the amount of imported water available. The developed conjunctive management model can provide HDWD water managers with information that will improve their ability to manage their surface water, reclaimed water, and groundwater resources.

California↗

The 3D Elevation Program: summary for Wyoming

Elevation data are essential to a broad range of applications, including forest resources management, wildlife and habitat management, national security, recreation, and many others. For the State of Wyoming, elevation data are critical for geologic resource assessment and hazard mitigation, flood risk management, water supply an quality, natural resources conservation, agriculture and precision farming, and other business uses. Today, high-density light detection and ranging (lidar) data are the primary sources for deriving elevation models and other datasets. Federal, State, Tribal, and local agencies work in partnership to (1) replace data that are older and of lower quality and (2) provide coverage where publicly accessible data do not exist. A joint goal of State and Federal partners is to acquire consistent, statewide coverage to support existing and emerging applications enabled by lidar data. The National Enhanced Elevation Assessment evaluated multiple elevation data acquisition options to determine the optimal data quality and data replacement cycle relative to cost to meet the identified requirements of the user community. The evaluation demonstrated that lidar acquisition at quality level 2 for the conterminous United States and quality level 5 interferometric synthetic aperture radar (ifsar) data for Alaska with a 6- to 10-year acquisition cycle provided the highest benefit/cost ratios.The 3D Elevation Program (3DEP) initiative selected an 8-year acquisition cycle for the respective quality levels. 3DEP, managed by the U.S. Geological Survey, the Office of Management and Budget Circular A–16 lead agency for terrestrial elevation data, responds to the growing need for high-quality topographic data and a wide range of other 3D representations of the Nation’s natural and constructed features.

Wyoming↗

Surface-water-quality assessment of the Yakima River basin in Washington: major-and minor-element data for sediment, water, and aquatic biota, 1987-91

Major- and minor-element concentrations are presented for streambed and suspended sediment, filtered- and unfiltered-water, and aquatic-biota samples collected during 1987-91 from the Yakima River Basin in south-central Washington. The samples were collected as part of the U.S. Geological Survey's National Water-quality Assessment (NAWQA) program which is designed to provide results that are useful in understanding and managing the Nation's water resources. This report includes the sampling approach, field collection and processing techniques, and methods of chemical analysis, as well as a compilation of chemical data, statistical summaries, and quality- control data. These data may be used by scientists and resource managers to describe (1) spatial distribution of selected major and minor elements in sediment, water, and aquatic biota of the Yakima River Basin; (2) temporal variation for element concentrations in filtered water and in suspended sediment at selected sites; (3) suita- bility of surface water for preservation of aquatic life and protection of human health; and (4) major natural and anthropogenic sources of major and minor elements in the Yakima River Basin that affect observed water-quality conditions. Streambed-sediment samples were collected once from 27 sites in the basin during 1987-91. Suspended-sediment and filtered-water samples were collected monthly and during hydrologic events (including snowmelt and winter rainstorms) at seven sites, and filtered-water samples were collected at least once at an additional 37 sites during synoptic samplings. Unfiltered-water samples were collected at seven sites on a quarterly basis during 1987 only. Samples of aquatic plants were collected once in 1989, and aquatic insects, fish, and clams were collected from 34 sites three times during 1989-90.

Washington↗

Geology and ground-water resources of the Ahtanum Valley, Yakima County, Washington

The Ahtanum Valley covers an area of about 100 square miles in an important agricultural district in central Yakima County, Wash. Because the area is semiarid, virtually all crops require irrigation. Surface-water supplies are inadequate in most of the area, and ground water is being used increasingly for irrigation. The purpose of this investigation was the collection and interpretation of data, pertaining to ground water in the area as an aid in the proper development and management of the water resources. The occurrence and movement of ground water in the Ahtanum Valley are directly related to the geology. The valley occupies part of a structural trough (Ahtanum-Moxee subbasin) that is underlain by strongly folded flow layers of a thick sequence of the Yakima basalt. The upper part of the basalt sequence interfingers with, and is conformably overlying by, sedimentary rocks of the Ellensburg formation which are as much as 1,000 feet thick. These rocks are in turn overlying unconformably by cemented basalt gravel as much as 400 feet thick. Unconsolidated alluvial sand and gravel, as much as 30 feet thick, form the valley floor. Although ground water occurs in each of the rock units within the area, the Yakima basalt and the unconsolidated alluvium yield about three-fourths of the ground water currently used. Wells in the area range in depth from a few feet to more than 1,200 feet and yield from less than 1 to more than 1,030 gallons per minute. Although water levels in water-table wells usually are shallow--often less than 5 feet below the land surface--levels in deeper wells tapping confined water range from somewhat above the land surface (in flowing wells) to about 200 feet below. Wells drilled into aquifers in the Yakima basalt, the Ellensburg formation, and the cemented gravel usually tap confined water, and at least 12 wells in the area flow or have flowed in the past. Ground-water levels fluctuate principally in response to changes in stream levels, variations in the flow of irrigation ditches and in rates of water application, variations in local precipitation, and seasonal differences in withdrawals from wells. Annual fluctuations of levels generally are less than 10 feet except in localities of heavy pumping. Periodic measurements of water levels in two observation wells in the area indicate, locally at least, a persistent decline in artesian pressures in confined basalt aquifers, although the record is too short to show whether withdrawal by pumping has reached, or is nearing, an optimum balance with recharge. The aquifers are recharged by precipitation, by infiltration from streams, and by ground-water underflow into the area. Ground water is discharged by seepage to streams, by evapotranspiration, by springs and seeps at the land surface, and, artificially, by withdrawal from wells. It is estimated that the seepage discharge to the Yakima River from the area studied may range from about 20,000 to 25,000 acre-feet per year. The consumptive waste of ground water by phreatophytes probably exceeds 4,000 acre-feet per year and may represent a large reclaimable source of water in the area. The annual withdrawal of ground water from wells in the area for domestic, industrial, irrigation, public, and stock supplies is estimated to be 6,300 acre-feet. The chemical quality of the ground water generally is satisfactory for most purposes, although the water from many wells is harder than is desirable for domestic use.

Washington↗

Trends in Streamflow Characteristics at Long-Term Gaging Stations, Hawaii

The surface-water resources of Hawaii have significant cultural, aesthetic, ecologic, and economic importance. Proper management of the surface-water resources of the State requires an understanding of the long- and short-term variability in streamflow characteristics that may occur. The U.S. Geological Survey maintains a network of stream-gaging stations in Hawaii, including a number of stations with long-term streamflow records that can be used to evaluate long-term trends and short-term variability in flow characteristics. The overall objective of this study is to obtain a better understanding of long-term trends and variations in streamflow on the islands of Hawaii, Maui, Molokai, Oahu, and Kauai, where long-term stream-gaging stations exist. This study includes (1) an analysis of long-term trends in flows (both total flow and estimated base flow) at 16 stream-gaging stations, (2) a description of patterns in trends within the State, and (3) discussion of possible regional factors (including rainfall) that are related to the observed trends and variations. Results of this study indicate the following: 1. From 1913 to 2002 base flows generally decreased in streams for which data are available, and this trend is consistent with the long-term downward trend in annual rainfall over much of the State during that period. 2. Monthly mean base flows generally were above the long-term average from 1913 to the early 1940s and below average after the early 1940s to 2002, and this pattern is consistent with the detected downward trends in base flows from 1913 to 2002. 3. Long-term downward trends in base flows of streams may indicate a reduction in ground-water discharge to streams caused by a long-term decrease in ground-water storage and recharge. 4. From 1973 to 2002, trends in streamflow were spatially variable (up in some streams and down in others) and, with a few exceptions, generally were not statistically significant. 5. Short-term variability in streamflow is related to the seasons and to the EL Ni?o-Southern Oscillation phenomenon that may be partly modulated by the phase of the Pacific Decadal Oscillation. 6. At almost all of the long-term stream-gaging stations considered in this study, average total flow (and to a lesser extent average base flow) during the winter months of January to March tended to be low following El Ni?o periods and high following La Ni?a periods, and this tendency was accentuated during positive phases of the Pacific Decadal Oscillation. 7. The El Ni?o-Southern Oscillation phenomenon occurs at a relatively short time scale (a few to several years) and appears to be more strongly related to processes controlling rainfall and direct runoff than ground-water storage and base flow. Long-term downward trends in base flows of streams may indicate a reduction in ground-water storage and recharge. Because ground water provides about 99 percent of Hawaii's domestic drinking water, a reduction in ground-water storage and recharge has serious implications for drinking-water availability. In addition, reduction in stream base flows may reduce habitat availability for native stream fauna and water availability for irrigation purposes. Further study is needed to determine (1) whether the downward trends in base flows from 1913 to 2002 will continue or whether the observed pattern is part of a long-term cycle in which base flows may eventually return to levels measured during 1913 to the early 1940s, (2) the physical causes for the detected trends and variations in streamflow, and (3) whether regional climate indicators successfully can be used to predict streamflow trends and variations throughout the State. These needs for future study underscore the importance of maintaining a network of long-term-trend stream-gaging stations in Hawaii.

Scientific Investigations Report↗

Assessing potential effects of changes in water use in the middle Carson River Basin with a numerical groundwater-flow model, Eagle, Dayton, and Churchill Valleys, west-central Nevada

During the economic boom of the mid part of the first decade of the 2000s in northwestern Nevada, municipal and housing growth increased use of the water resources of this semi-arid region. In 2008, when the economy slowed, new housing development stopped, and immediate pressure on groundwater resources abated. The U.S. Geological Survey, in cooperation with the Bureau of Reclamation, began a hydrogeologic study of the middle Carson River Basin. The first half of the study reviewed and synthesized previous geologic studies and contributed new datasets that served as a foundation for a three-dimensional, transient numerical model of groundwater and surface-water flow for the middle Carson River Basin extending from Eagle Valley to Churchill Valley. The model can be used to evaluate the effects of proposed alternative management strategies on groundwater sustainability, flows in the Carson River, and routine operation of Lahontan Reservoir and can also provide a basis for basin-wide investigations seeking to quantitatively evaluate the effects of climate change or yet-to-be-determined alternative management strategies. The middle Carson model was constructed using the U.S. Geological Survey groundwater modeling software MODFLOW-NWT. MODFLOW is widely used groundwater modeling software and is well-suited for evaluating groundwater and surface-water interactions. The model uses 550-feet square grid cells that align with the previously published model for Carson Valley (adjacent upstream valley). Six grid layers with more finely resolved vertical resolution near the perimeter of the active model domain and near surface-water features, compared to other areas of the active model domain, hone the simulated groundwater and surface-water exchanges. In addition to simulating groundwater and surface-water interaction, crop and phreatophyte evapotranspiration, lake evaporation, mountain-front recharge, recharge from irrigation return flows, and groundwater pumping are also simulated. Surface-water flow entering the model domain, including the Carson River, tributary inflow from perennial streams in Eagle Valley, and trans-basin imports through the Truckee Canal (surface water diverted from the Truckee River) are specified according to U.S. Geological Survey streamgage records. Groundwater pumpage and surface-water diversions to 10 agricultural ditches and the managed release from Lahontan Reservoir, at the end of the middle Carson River Basin, are specified according to water-manager records. The model simulation period extended from 2000 through 2010 (January 1, 2000, to December 31, 2010) using 574 weekly stress periods, with a single steady-state stress period at the beginning of the simulation that establishes initial conditions by approximating average conditions during the transient simulation period. All available observations for this period were used during the model calibration process, performed using automated parameter-estimation software. Calibration targets included observations of groundwater elevations in wells, streamflow, differences in observed streamflow between successive streamgages and actual evapotranspiration from irrigated lands. Among all 5,296 simulated and observed groundwater level pairs, the mean error was 1.42 feet; the mean absolute error, 7.71 feet; and the percent bias was −0.1 percent. Three alternative management scenarios, run using the entire period of analysis (2000–10), were simulated to improve understanding of the potential effects of (1) loss of irrigated agricultural lands following conversion of water-rights to municipal groundwater rights; (2) reclaiming treated wastewater with induction wells; and (3) exercising permitted but under-utilized groundwater rights. Scenarios 2 and 3 were further explored using two and four subscenarios, respectively. Simulated scenario results ranged from having little effect on the groundwater system relative to a baseline simulation to having spatially extensive and large groundwater-level declines (10 to 20 feet) compared to the baseline simulation. None of the simulated scenarios increased delivery of river flows to Lahontan Reservoir. On the contrary, one of the subscenarios under alternative management scenario 3 led to surface-water delivery shortfalls of more than 10,000 acre-feet per year. Future model improvements may include an extension of the model simulation period backward and forward in time and directly linking it to the upstream Carson Valley groundwater model. Furthermore, converting this MODFLOW model to a GSFLOW model, which fully integrates groundwater and surface-water flows including precipitation runoff and infiltration, may provide an improved tool for comprehensive management of water-resources in the middle Carson River Basin.

Nevada↗

NBII-SAIN Data Management Toolkit

The Strategic Plan for the U.S. Geological Survey Biological Informatics Program (2005-2009) recognizes the need for effective data management: Though the Federal government invests more than $600 million per year in biological data collection, it is difficult to address these issues because of limited accessibility and lack of standards for data and information...variable quality, sources, methods, and formats (for example observations in the field, museum specimens, and satellite images) present additional challenges. This is further complicated by the fast-moving target of emerging and changing technologies such as GPS and GIS. Even though these technologies offer new solutions, they also create new informatics challenges (Ruggiero and others, 2005). The USGS National Biological Information Infrastructure program, hereafter referred to as NBII, is charged with the mission to improve the way data and information are gathered, documented, stored, and accessed. The central objective of this project is a direct reflection of the purpose of NBII as described by John Mosesso, Program Manager of the U.S. Geological Survey-Biological Informatics Program-GAP Analysis: At the outset, the reason for bringing about NBII was that there were significant amounts of data and information scattered all over the U.S., not accessible, in incompatible formats, and that NBII was tasked with addressing this problem...NBII's focus is to pull data together that truly matters to someone or communities. Essentially, the core questions are: 1) what are the issues, 2) where is the data, and 3) how can we make it usable and accessible (John Mosesso, U.S. Geological Survey, oral commun., 2006). Redundancy in data collection can be a major issue when multiple stakeholders are involved with a common effort. In 2001 the U.S. General Accounting Office (USGAO) estimated that about 50 percent of the Federal government's geospatial data at the time was redundant. In addition, approximately 80 percent of the cost of a spatial information system is associated with spatial data collection and management (U.S. General Accounting Office, 2003). These figures indicate that the resources (time, personnel, money) of many agencies and organizations could be used more efficiently and effectively. Dedicated and conscientious data management coordination and documentation is critical for reducing such redundancy. Substantial cost savings and increased efficiency are direct results of a pro-active data management approach. In addition, details of projects as well as data and information are frequently lost as a result of real-world occurrences such as the passing of time, job turnover, and equipment changes and failure. A standardized, well documented database allows resource managers to identify issues, analyze options, and ultimately make better decisions in the context of adaptive management (National Land and Water Resources Audit and the Australia New Zealand Land Information Council on behalf of the Australian National Government, 2003). Many environmentally focused, scientific, or natural resource management organizations collect and create both spatial and non-spatial data in some form. Data management appropriate for those data will be contingent upon the project goal(s) and objectives and thus will vary on a case-by-case basis. This project and the resulting Data Management Toolkit, hereafter referred to as the Toolkit, is therefore not intended to be comprehensive in terms of addressing all of the data management needs of all projects that contain biological, geospatial, and other types of data. The Toolkit emphasizes the idea of connecting a project's data and the related management needs to the defined project goals and objectives from the outset. In that context, the Toolkit presents and describes the fundamental components of sound data and information management that are common to projects involving biological, geospatial, and other related data

Open-File Report↗

A strategy for a stream-gaging network in Maryland

Water is a keystone resource. In abundance, it supplies cities, industries, and agriculture. To maintain healthy natural and human ecosystems, water must not only be present in adequate quantity, but it must be of suitable quality for its intended use. Water quality depends on the amount, or load, of contaminants, both natural and anthropogenic, that it contains. Accurate assessment of these contaminants requires that the amount of water flowing in a stream or river be known. To quantify streamflow in a given stream or river and the variation of that flow through time, it must be measured by use of stream gages. Monitoring water flow is fundamental to managing and protecting water resources, and requires a collaborative effort by all interested parties, including Federal, State, and local government agencies.

Maryl↗

Simulation of Regional Ground-Water Flow in the Suwannee River Basin, Northern Florida and Southern Georgia

The Suwannee River Basin covers a total of nearly 9,950 square miles in north-central Florida and southern Georgia. In Florida, the Suwannee River Basin accounts for 4,250 square miles of north-central Florida. Evaluating the impacts of increased development in the Suwannee River Basin requires a quantitative understanding of the boundary conditions, hydrogeologic framework and hydraulic properties of the Floridan aquifer system, and the dynamics of water exchanges between the Suwannee River and its tributaries and the Floridan aquifer system. Major rivers within the Suwannee River Basin are the Suwannee, Santa Fe, Alapaha, and Withlacoochee. Four rivers west of the Suwannee River are the Aucilla, the Econfina, the Fenholloway, and the Steinhatchee; all drain to the Gulf of Mexico. Perhaps the most notable aspect of the surface-water hydrology of the study area is that large areas east of the Suwannee River are devoid of channelized, surface drainage; consequently, most of the drainage occurs through the subsurface. The ground-water flow system underlying the study area plays a critical role in the overall hydrology of this region of Florida because of the dominance of subsurface drain-age, and because ground-water flow sustains the flow of the rivers and springs. Three principal hydrogeologic units are present in the study area: the surficial aquifer system, the intermediate aquifer system, and the Floridan aquifer system. The surficial aquifer system principally consists of unconsoli-dated to poorly indurated siliciclastic deposits. The intermediate aquifer system, which contains the intermediate confining unit, lies below the surficial aquifer system (where present), and generally consists of fine-grained, uncon-solidated deposits of quartz sand, silt, and clay with interbedded limestone of Miocene age. Regionally, the intermediate aquifer system and intermediate con-fining unit act as a confining unit that restricts the exchange of water between the over-lying surficial and underlying Upper Floridan aquifers. The Upper Floridan aquifer is present throughout the study area and is extremely permeable and typically capable of transmitting large volumes of water. This high permeability largely is due to the widening of fractures and formation of conduits within the aquifer through dissolu-tion of the limestone by infiltrating water. This process has also produced numerous karst features such as springs, sinking streams, and sinkholes. A model of the Upper Floridan aquifer was created to better understand the ground-water system and to provide resource managers a tool to evaluate ground-water and surface-water interactions in the Suwannee River Basin. The model was developed to simulate a single Upper Floridan aquifer layer. Recharge datasets were developed to represent a net flux of water to the top of the aquifer or the water table during a period when the system was assumed to be under steady-state conditions (September 1990). A potentiometric-surface map representing water levels during September 1990 was prepared for the Suwannee River Water Management District (SRWMD), and the heads from those wells were used for calibration of the model. Additionally, flows at gaging sites for the Suwannee, Alapaha, Withlacoochee, Santa Fe, Fenholloway, Aucilla, Ecofina, and Steinhatchee Rivers were used during the calibration process to compare to model computed flows. Flows at seven first-magnitude springs selected by the SRWMD also were used to calibrate the model. Calibration criterion for matching potentiometric heads was to attain an absolute residual mean error of 5 percent or less of the head gradient of the system which would be about 5 feet. An absolute residual mean error of 4.79 feet was attained for final calibration. Calibration criterion for matching streamflow was based on the quality of measurements made in the field. All measurements used were rated ?good,? so the desire was for simulated values to be wi

Florida, Georgia↗

Obtaining Streamflow Statistics for Massachusetts Streams on the World Wide Web

A World Wide Web application has been developed to make it easy to obtain streamflow statistics for user-selected locations on Massachusetts streams. The Web application, named STREAMSTATS (available at http://water.usgs.gov/osw/streamstats/massachusetts.html ), can provide peak-flow frequency, low-flow frequency, and flow-duration statistics for most streams in Massachusetts. These statistics describe the magnitude (how much), frequency (how often), and duration (how long) of flow in a stream. The U.S. Geological Survey (USGS) has published streamflow statistics, such as the 100-year peak flow, the 7-day, 10-year low flow, and flow-duration statistics, for its data-collection stations in numerous reports. Federal, State, and local agencies need these statistics to plan and manage use of water resources and to regulate activities in and around streams. Engineering and environmental consulting firms, utilities, industry, and others use the statistics to design and operate water-supply systems, hydropower facilities, industrial facilities, wastewater treatment facilities, and roads, bridges, and other structures. Until now, streamflow statistics for data-collection stations have often been difficult to obtain because they are scattered among many reports, some of which are not readily available to the public. In addition, streamflow statistics are often needed for locations where no data are available. STREAMSTATS helps solve these problems. STREAMSTATS was developed jointly by the USGS and MassGIS, the State Geographic Information Systems (GIS) agency, in cooperation with the Massachusetts Departments of Environmental Management and Environmental Protection. The application consists of three major components: (1) a user interface that displays maps and allows users to select stream locations for which they want streamflow statistics (fig. 1), (2) a data base of previously published streamflow statistics and descriptive information for 725 USGS data-collection stations, and (3) an automated procedure that determines characteristics of the land-surface area (basin) that drains to the stream and inserts those characteristics into equations that estimate the streamflow statistics. Each of these components is described and guidance for using STREAMSTATS is provided below.

Fact Sheet↗

Streamflow reconstruction in the Upper Missouri River Basin using a novel Bayesian network model

A Bayesian model that uses the spatial dependence induced by the river network topology, and the leading principal components of regional tree-ring chronologies for paleo-streamflow reconstruction is presented. In any river basin, a convergent, dendritic network of tributaries comes together to form the main stem of a river. Consequently, it is natural to think of a spatial Markov process that recognizes this topological structure to develop a spatially consistent basin-scale streamflow reconstruction model that uses the information in streamflow and tree-ring chronology data to inform the reconstructed flows, while maintaining the space-time correlation structure of flows that is critical for water resource assessments and management. Given historical data from multiple streamflow gauges along a river, their tributaries in a watershed, and regional tree-ring chronologies, the model is fit and used to simultaneously reconstruct the full network of paleo-streamflow at all gauges in the basin progressing upstream to downstream along the river. The spatial network structure allows a substantial reduction in the uncertainty associated with paleo-streamflow as one proceeds downstream in the network and the spatial dependence structure increases the information content. Our application to eighteen streamflow gauges in the Upper Missouri River Basin shows that the mean adjusted-R2 for the basin is approximately 0.5 with good overall cross-validated skill as measured by five different skill metrics. A comparison with the traditional principal components regression shows that the spatial Bayesian model offers improvements, as downstream gauges are informed by the reconstruction of the upstream gauges, as well as the tree-ring chronologies.

Idaho, Montana, Wyoming↗

Assessment of water resources and the potential effects from oil and gas development in the Bureau of Land Management Tri-County planning area, Sierra, Doña Ana, and Otero Counties, New Mexico

The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, conducted a study to assess the water resources and potential effects on the water resources from oil and gas development in the Tri-County planning area, Sierra, Doña Ana, and Otero Counties, New Mexico. Publicly available data were used to assess these resources and effects and to identify data gaps in the Tri-County planning area. The Tri-County planning area includes approximately 9.3 million acres and is within the eastern extent of the Basin and Range Province, which consists of mountain ranges and low elevation basins. Three specific areas of interest within the Tri-County planning area are the Jornada del Muerto, Tularosa Basin, and Otero Mesa, which is adjacent to the Salt Basin. Surface-water resources are limited in the Tri-County planning area, with the Rio Grande as the main perennial river flowing from north to south through Sierra and Doña Ana Counties. The Tularosa Creek is an important surface-water resource in the Tularosa Basin. The Sacramento River, which flows southeast out of the Sacramento Mountains, is an important source of recharge to aquifers in the Salt Basin. Groundwater resources vary in aquifer type, depth to water, and water quality. For example, the Jornada del Muerto, Tularosa Basin, and Salt Basin each have shallow and deep aquifer systems, and water can range from freshwater, with less than 1,000 milligrams per liter (mg/L) of total dissolved solids, to brine, with greater than 35,000 mg/L of total dissolved solids. Water quality in the Tri-County planning area is affected by the dissolution of salt deposits and evaporation which are common in arid regions such as southern New Mexico. The potential for oil and gas development exists in several areas within the Tri-County area. As many as 81 new conventional wells and 25 coalbed natural gas wells could be developed by 2035. Conventional oil and gas well construction in the Tri-County planning area is expected to require 1.53 acre-feet (acre-ft) (500,000 gallons) of water per well, similar to requirements in the nearby Permian Basin of New Mexico, while construction of unconventional wells is expected to require 7.3 acre-ft of water per well. Produced waters in the Permian Basin have high total dissolved solids, in the brackish to brine range. Data gaps identified in this study include the limited detailed data on surface-water resources, the lack of groundwater data in areas of interest, and the lack of water chemistry data related to oil and gas development issues. Surface waters in the Tri-County planning area are sparse; some streams are perennial, and most are ephemeral. A more detailed study of the ephemeral channels and their interaction with groundwater could provide a better understanding of the importance of these surface-water resources. Groundwater data used in this study are from the USGS National Water Information System, which does not have continuous water-level depth data at many of the sites in the Tri-County planning area. On Otero Mesa, no recurrent groundwater-level data are available at any one site. The water-quality data compiled in this study provide a good overview of the general chemistry of groundwater in the Tri-County planning area. To fully understand the groundwater resources, it would be helpful to have more wells in specific areas of interest for groundwater-level and water-quality measurements.

New Mexico↗