Groundwater Elevation Change Maps summarize the change in groundwater level measurements over time, collected from wells in the northern Sacramento Valley by the Department of Water Resources (DWR) Northern Region Office (NRO) and monitoring cooperators. Northern Sacramento Valley groundwater levels are measured seasonally, during the annual water year, as part of our ongoing data collection program. Many of the wells have over 30 years of monitoring history, with the longest active monitoring well dating back to 1921. Groundwater level data provides valuable information regarding seasonal fluctuations and long-term changes in groundwater level trends over time. The groundwater level data presented in these figures includes the Sacramento Valley and Redding groundwater basin portions of Shasta, Tehama, Butte, Colusa, Glenn, and Sutter counties and are organized by year, season, well depth, and period of change.

The map graphic image at https://www.sciencebase.gov/catalog/file/get/63140561d34e36012efa2b7f?name=arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about 31,000 wells and springs in 49 states compiled by the United States Geological Survey (USGS). The map graphic illustrates an updated version of figure 1 from Ryker (2001). Cited Reference: Ryker, S.J., Nov. 2001, Mapping arsenic in groundwater-- A real need, but a hard problem: Geotimes Newsmagazine of the Earth Sciences, v. 46 no. 11, p. 34-36 at http://www.agiweb.org/geotimes/nov01/feature_Asmap.html. An excel tabular data file, a txt file, along with a GIS shape file of arsenic concentrations (20,043 samples collected by the USGS) for a subset of the sites shown on the map. Samples were collected between 1973 and 2001 and are provided for download.

This dataset is available for use for non-commercial purposes only on request as AfA248 dataset Groundwater Vulnerability Maps (2017). For commercial use please contact the British Geological Survey.

The Groundwater Vulnerability Maps show the vulnerability of groundwater to a pollutant discharged at ground level based on the hydrological, geological, hydrogeological and soil properties within a single square kilometre. The 2017 publication has updated the groundwater vulnerability maps to reflect improvements in data mapping, modelling capability and understanding of the factors affecting vulnerability Two map products are available: • The combined groundwater vulnerability map. This product is designed for technical specialists due to the complex nature of the legend which displays groundwater vulnerability (High, Medium, Low), the type of aquifer (bedrock and/or superficial) and aquifer designation status (Principal, Secondary, Unproductive). These maps require that the user is able to understand the vulnerability assessment and interpret the individual components of the legend.

• The simplified groundwater vulnerability map. This was developed for non-specialists who need to know the overall risk to groundwater but do not have extensive hydrogeological knowledge or the time to interpret the underlying data. The map has five risk categories (High, Medium-High, Medium, Medium-Low and Low) based on the likelihood of a pollutant reaching the groundwater (i.e. the vulnerability), the types of aquifer present and the potential impact (i.e. the aquifer designation status). The two maps also identify areas where solution features that enable rapid movement of a pollutant may be present (identified as stippled areas) and areas where additional local information affecting vulnerability is held by the Environment Agency (identified as dashed areas).

A comprehensive picture, at European Union scale, of the aquifers and their characteristics is available in digital form. In 1982, a study by the European Commission provided a complete catalogue of national water resources for several Member States of the European Union (Belgium, Federal Republic of Germany, Denmark, France, Ireland, Italy, Luxembourg, Netherlands and United Kingdom).

This catalogue comprised a series of groundwater resources maps of Europe, at scale 1:500,000 ; there were 38 map sheets covering four themes:

-Inventory of aquifers; -Hydrogeology of aquifers; -Groundwater abstraction; -Potential additional groundwater resources.

[Summary provided by the European Union Joint Research Center.]

Groundwater in the arid Mountain Home area is vital to agricultural, municipal, industrial and other water users who are concerned about declining groundwater levels. The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources (IDWR), developed a hydrogeologic framework to provide a conceptual understanding of groundwater resources in the Mountain Home area. As part of the hydrogeologic framework, water-table contour and groundwater-level change maps were produced to describe the occurrence, movement, and change in groundwater. Water-table contours for spring 2023 (March 20 to 24, 2023) and autumn 2023 (November 1 to 7, 2023) were created for the regional aquifer and perched groundwater zone in the Mountain Home area. The well numbers and station names for sites used to create the water-table contours and groundwater-level change and groundwater storage change rasters are provided in this data release. The location, depth to water, and groundwater altit ...

Map Direct focus to show Groundwater Contamination. Please refer to https://floridadep.gov/water for more information. Originally created 03/01/2007, and moved to Map Direct Lite on 06/24/2015. Please contact GIS.Librarian@floridadep.gov for more information.

Union County, the northeasternmost county in New Mexico, is rural with an economy based on ranching and agriculture. Surface water resources are limited, thus development of groundwater for stock watering and irrigation is important and extensive. Groundwater studies by the New Mexico Bureau of Geology and Mineral Resources (NMBGMR) in Union County have been conducted in concert with the Northeast Soil and Water Conservation District (NESWCD) and were driven by concerns over recent large groundwater appropriations, the reliability of the groundwater supply for the town of Clayton, and declining water levels that have been observed in many wells over the past few years.

The New Mexico Office of the State Engineer (NMOSE) declared the Clayton Underground Water Basin in 2005, ending unrestricted appropriation and development of groundwater in northeast New Mexico. Recently, the NMOSE has started development of a groundwater flow model of the Clayton Basin for administration of water rights. Important input data for a groundwater flow model include accurate delineation of the groundwater surface and an understanding of water level changes over time.

This part of the data release contains the water-level measurement data compiled and synthesized from various sources. This compilation includes two tables that contain all the water-level measurements that were considered in the development of the groundwater-level altitude maps (Input_VisGWDB), and a table of median-water-level data that were used to develop the groundwater-level altitude maps (MedianWaterLevelData). Also included in this part of the data release is a geologic unit code look-up table which defines the geologic units that wells are reported to be screened in for wells with water-level measurements. These digital data accompany Houston, N.A., Thomas, J.V., Foster, L.K., Pedraza, D.E., and Welborn, T.L., 2020, Hydrogeologic framework, groundwater-level altitudes, groundwater-level changes, and groundwater-storage changes in selected alluvial basins in the upper Rio Grande focus area study, Colorado, New Mexico, and Texas, U.S. and Chihuahua, Mexico, 1980 to 2015

Groundwater is the water that soaks into the ground from rain and can be stored beneath the ground. An aquifer is a body of rock and/or sediment that holds groundwater. There are two main types of aquifer in Ireland – bedrock aquifers, and sand and gravel aquifers. Bedrock is the solid rock at or below the land surface. Over much of Ireland, the bedrock is covered by materials such as sands and gravel. The sands and gravels occur naturally on top of the bedrock. They were laid down by meltwater from melting ice sheets, by rivers, or by wind. There are two main types of bedrock aquifer. In most of them, groundwater flows through fractures and fissures. In about half of the limestone rocks, groundwater flows through cavities and caves. This type of limestone is called karst. Not all sand and gravel layers are aquifers. This is because some of them are very thin or are dry. If the sands and gravels are saturated with water, they have the potential to supply large volumes of water through wells or springs. The aquifer maps show the potential of areas in Ireland to provide water supplies. There are three main groups based on their resource potential: Regionally important – the aquifers are capable of supporting large public water supplies sufficient to support a large town; Locally important – the aquifers are capable of supporting smaller public water supplies or group schemes; Poor – the aquifers are only capable of supporting small supplies, such as houses or farms, or small group schemes. The three main groups are broken down into nine aquifer categories in total. Please read the lineage for further details. Information used to assign bedrock aquifer categories include: rock type (Hydrostratigraphic Rock Unit Groups - simplified bedrock geology with similar hydrogeological properties), yield (existing wells and springs), permeability and structural characteristics. All of the information is interpreted by a hydrogeologist and areas are drawn on a map to show the aquifers. The Sand and Gravel Aquifer map is to the scale 1:40,000 (1 cm on the map relates to a distance of 400 m). It is a vector dataset. The sand and gravel aquifer data is shown as polygons. Each polygon holds information on the aquifer code, description, name, comments and confidence level associated with the delineation of the area as an aquifer. The Aquifer Geological Lines shows the details of the structural geology; faults and thrusts. Faults are the result of great pressure being applied to rock across a whole continent or more. These rocks break under the pressure, forming faults. Faults are recorded as lines where the break in the rock meets the surface. A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Geologists map and record information on the composition and structure of rock outcrops (rock which can be seen on the land surface) and boreholes (a deep narrow round hole drilled in the ground). Lines are drawn on a map to show the structure. To produce this dataset, the twenty one 1:100,000 paper maps covering Ireland were digitised and any inconsistencies between map sheets were fixed. We collect new data to update our map and also use data made available from other sources. This map is to the scale 1:100,000 (1cm on the map relates to a distance of 1km). It is a vector dataset. The Geological Lines data is shown as lines. Each line holds information on: description of the line, bedrock 100k map sheet number, line code and name (if it has one).

Groundwater potentiometric-surface contours for spring 2022 (April 4 to 8, 2022) and autumn 2022 (October 30 to November 4, 2022) were created for the alluvial aquifer in Big Lost River Valley. The well numbers and station names used to create the potentiometric-surface contours and groundwater-level change maps are provided in this data release. The location, depth to water, and potentiometric-surface altitude for these wells can be accessed on USGS National Water Information System (NWIS) or Idaho Department of Water Resources (IDWR) groundwater portal. The interpreted 20-foot contours of the potentiometric-surface are also provided in this data release. The contours are referenced to the North American Vertical Datum of 1988 (NAVD 88). The potentiometric-surface contours are divided into three water-bearing units - shallow, intermediate, and deep - based on well depth, potentiometric-surface altitude, and hydrogeologic unit. The intermediate and deep units were only identified in the southern portion of the valley near Arco, Idaho. The potentiometric-surface contours ranged from 4,900 to 6,660 feet above NAVD 88. The groundwater-level change at well sites from spring to autumn 2022, spring to autumn 1968, spring 1968 to spring 2022, spring 1991 to spring 2022, and spring 1968 to spring 1991 were calculated and are provided in a shapefile.

Groundwater flow is the movement of water in an aquifer or hydrogeological unit. The dataset shows groundwater flow rate and direction in the hydrogeological unit. Groundwater flow is establish from piezometric surface map. The method used to create the dataset is described in the metadata associated with the dataset. The dataset represents a description of the flow, including rate in m/d, direction, date and source. Typically, the data provided will not be in the form of a shapefile with linked properties but in the form of an image that sketches the groundwater flow. The image could also represent a cross section of the hydrogeologic units showing the regional trends of the groundwater flow.

This project consists of 11 files: 1) a zipped folder with a geodatabase containing seven raster files and two shapefiles, 2) a zipped folder containing the same layers found in the geodatabase, but as standalone files, 3) 9 .xml files containing the metadata for the spatial datasets in the zipped folders. These datasets were generated in ArcPro 3.0.3. (ESRI). Six raster files (drainaged, geology, nlcd, precipitation, slope, solitexture) present spatially distributed information, ranked according to the relative importance of each class for groundwater recharge. The scale used for these datasets is 1-9, where low scale values are assigned to datasets with low relative importance for groundwater recharge, while high scale values are assigned to datasets with high relative importance for groundwater recharge. The seventh raster file contains the groundwater recharge potential map for the Anchor River Watershed. This map was calculated using the six raster datasets mentioned previously. Here, the values assigned represent Very Low to Very High groundwater recharge potential (scale 1 - 5, 1 being Very Low and 5 being Very High). Finally, the two shapefiles represent the groundwater wells and the polygons used for model validation. This data is part of the manuscript titled: Mapping Groundwater Recharge Potential in High Latitude Landscapes using Public Data, Remote Sensing, and Analytic Hierarchy Process, published in the journal remote sensing.

Groundwater/Aquifer maps and cross-sections for southern Saskatchewan. The maps are by 1:250,000 scale NTS mapsheet and are in PDF format.

Spatial coverage index compiled by East View Geospatial of set "Yemen 1:500,000 Groundwater Resources Map". Source data from MOM (publisher). Type: Geoscientific - Energy Resources. Scale: 1:500,000. Region: Middle East.

Groundwater levels of important aquifers as a specialist layer of the digital hydrogeological map 1:100,000. It is recommended to display them together with the separate specialist layers for groundwater levels and bases for constructing the groundwater levels. Zoom limitation min. 1:200,000 to max. 1:50,000. Groundwater levels are lines of the same height of a groundwater surface or groundwater pressure area. The dHK100 was created in the period from 2000 to 2015 (planning region 14 Munich to 2019) according to planning regions. The basis for the creation of the groundwater balance is the knowledge of groundwater levels in boreholes, wells, groundwater measuring points and springs as well as in surface waters, which are interpolated to lines of the same height taking into account hydrogeological and hydraulic conditions. Inaccuracies in the construction of the groundwater levels result in particular from the uneven distribution of the exploration points. A systematic update of the dHK100 does not take place. Due to the planning region-wise processing over longer periods of time, geometric and attributive inconsistencies can occur along the planning region borders between the groundwater levels that meet there. These are due to different basic data from which the groundwater levels are derived. Geometries and legend units are designed for the overview scale 1:100 000 (1 cm on a map corresponds to 1 km in nature) and i. i.e. R. strongly generalized. The dHK100 or HK100 is intended as a basis for large-scale observations. It does not replace detailed investigations and assessments by a specialist office when planning local projects. The scale-related statement accuracy does not change due to the scale-independent visualization options of digital maps. For further interpretations that combine or overlay the map series with other spatial datasets, it should be noted that an overlay of spatial data with very different resolutions or different target scales or different types of attribution can lead to implausible results or results that are difficult to interpret.

Statistical analyses and maps representing mean, high, and low water-level conditions in the surface water and groundwater of Miami-Dade County were made by the U.S. Geological Survey, in cooperation with the Miami-Dade County Department of Regulatory and Economic Resources, to help inform decisions necessary for urban planning and development. Sixteen maps were created that show contours of (1) the mean of daily water levels at each site during October and May for the 2000-2009 water years; (2) the 25th, 50th, and 75th percentiles of the daily water levels at each site during October and May and for all months during 2000-2009; and (3) the differences between mean October and May water levels, as well as the differences in the percentiles of water levels for all months, between 1990-1999 and 2000-2009. The 80th, 90th, and 96th percentiles of the annual maximums of daily groundwater levels during 1974-2009 (a 35-year period) were computed to provide an indication of unusually high groundwater-level conditions. These maps and statistics provide a generalized understanding of the variations of water levels in the aquifer, rather than a survey of concurrent water levels. Water-level measurements from 473 sites in Miami-Dade County and surrounding counties were analyzed to generate statistical analyses. The monitored water levels included surface-water levels in canals and wetland areas and groundwater levels in the Biscayne aquifer. Maps were created by importing site coordinates, summary water-level statistics, and completeness of record statistics into a geographic information system, and by interpolating between water levels at monitoring sites in the canals and water levels along the coastline. Raster surfaces were created from these data by using the triangular irregular network interpolation method. The raster surfaces were contoured by using geographic information system software. These contours were imprecise in some areas because the software could not fully evaluate the hydrology given available information; therefore, contours were manually modified where necessary. The ability to evaluate differences in water levels between 1990-1999 and 2000-2009 is limited in some areas because most of the monitoring sites did not have 80 percent complete records for one or both of these periods. The quality of the analyses was limited by (1) deficiencies in spatial coverage; (2) the combination of pre- and post-construction water levels in areas where canals, levees, retention basins, detention basins, or water-control structures were installed or removed; (3) an inability to address the potential effects of the vertical hydraulic head gradient on water levels in wells of different depths; and (4) an inability to correct for the differences between daily water-level statistics. Contours are dashed in areas where the locations of contours have been approximated because of the uncertainty caused by these limitations. Although the ability of the maps to depict differences in water levels between 1990-1999 and 2000-2009 was limited by missing data, results indicate that near the coast water levels were generally higher in May during 2000-2009 than during 1990-1999; and that inland water levels were generally lower during 2000-2009 than during 1990-1999. Generally, the 25th, 50th, and 75th percentiles of water levels from all months were also higher near the coast and lower inland during 2000–2009 than during 1990-1999. Mean October water levels during 2000-2009 were generally higher than during 1990-1999 in much of western Miami-Dade County, but were lower in a large part of eastern Miami-Dade County.

The Provincial Groundwater Monitoring Network (PGMN) datasets report on ambient (baseline) groundwater level and chemistry conditions.

Groundwater monitoring map

Data supporting the publication:Cuthbert et al (2019). Global patterns and dynamics of climate–groundwater interactions. Nature Climate Change, 9, 137–141. DOI:10.1038/s41558-018-0386-4https://www.nature.com/articles/s41558-018-0386-4See the ReadMe file uploaded with the data and the Methods section of the paper for details of the derivation of each dataset.

This data release contains data used to develop models and maps that estimate the occurrence of lithium in groundwater used as drinking water throughout the conterminous United States. An extreme gradient boosting model was developed to estimate the most probable lithium concentration category (≤4, >4 to ≤10, >10 to ≤30 or >30 µg/L). The model uses lithium concentration data from wells located throughout the conterminous United States and predictor variables that are available as geospatial data. The model is included in this data release in the zipped folder named Model_Archive and was used to produce maps that are also included in this data release. The model input data (predictor variables) that were used to make the maps are within a zipped folder (Map_Input_Data.zip) that contains 20 tif-raster files, one for each model predictor variable. The map probability estimates that are outputs from the model are in a zipped folder (Map_Output_Data.zip) that contains 10 tif-raster files, two model estimate maps for each of the lithium concentration categories and the category with the highest probability for public supply well depths and domestic supply well depths.

The U.S. Geological Survey (USGS) is providing online maps of water-table and potentiometric-surface altitude in the upper glacial, Magothy, Jameco, Lloyd, and North Shore aquifers on Long Island, New York, April May 2016. Also provided is a depth-to-water map for Long Island, New York, April May 2016. The USGS makes these maps and geospatial data available as REST Open Map Services (as well as HTTP, JSON, KML, and shapefile), so end-users can consume them on mobile and web clients. A companion report, U.S. Geological Survey Scientific Investigations Map 3398 (Como and others, 2018; https://doi.org/10.3133/sim3398) further describes data collection and map preparation and presents 68x22 in. Portable Document Form (PDF) versions, 4 sheets, scale 1:125,000.

The USGS, in cooperation with State and local agencies, systematically collects groundwater data at varying measurement frequencies to monitor the hydrologic conditions on Long Island, New York. Each year during April and May, the USGS completes a synoptic survey of water levels to define the spatial distribution of the water table and potentiometric surfaces within the three main water-bearing units underlying Long Islandthe upper glacial, Magothy, and Lloyd aquifers (Smolensky and others, 1989)and the hydraulically connected Jameco (Soren, 1971) and North Shore aquifers (Stumm, 2001). These data and the maps constructed from them are commonly used in studies of the hydrology of Long Island and are used by water managers and suppliers for aquifer management and planning purposes. Sheets 1 4 in U.S. Geological Survey Scientific Investigations Map 3398 (Como and others, 2018; https://doi.org/10.3133/sim3398) were prepared using water-level data measured at 424 groundwater monitoring wells (observation and supply) and 15 streamgages across Long Island during April and May of 2016. Additionally, digital datasets were derived from the water-level observations that include (1) contour lines and a continuous raster of the depth to water table in the upper glacial and Magothy aquifers, (2) contour lines of the potentiometric surface in the middle to deep Magothy aquifer and the hydraulically connected Jameco aquifer, (3) contour lines of the potentiometric surface in the Lloyd aquifer and hydraulically connected North Shore aquifer, and (4) point feature classes for the 424 groundwater-monitoring wells and 15 streamgages where water levels were collected.

Data Sources

Water-level measurements made in 424 monitoring wells (observation and supply wells), 13 streamgages, and 2 lake gages across Long Island during April May 2016 were used to prepare the maps in this report. Groundwater measurements were made by the wetted-tape or electric-tape method to the nearest hundredth of a foot. Many of the supply wells are in continuous operation and, therefore, were turned off for a minimum of 24 hours before measurements were made to allow the water levels in the wells to recover to ambient (nonpumping) conditions. Full recovery time at some of these supply wells can exceed 24 hours; therefore, water levels measured at these wells are assumed to be less accurate than those measured at observation wells, which are not pumped (Busciolano, 2002). In addition to pumping stresses, density differences (saline water) also lower the water levels measured in certain wells (Lusczynski, 1961). In this report, all water-level altitudes are referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).

Analysis

Contours of water-table and potentiometric-surface altitudes were created using the groundwater measurements. The water-table contours were interpreted using water-level data collected from 13 streamgages, 2 lake gages, 275 observation wells, and 1 supply well screened in the upper glacial aquifer or the shallow Magothy aquifer. The potentiometric-surface contours of the Magothy aquifer were interpreted from measurements at 88 wells (61 observation wells and 27 supply wells) screened in the middle to deep Magothy aquifer and the contiguous and hydraulically connected Jameco aquifer. The potentiometric-surface contours of the Lloyd aquifer were interpreted from measurements at 60 wells (55 observation wells and 5 supply wells) screened in the Lloyd aquifer and the contiguous and hydraulically connected North Shore aquifer. Editing of the geospatial data was done in ArcGIS Desktop (Esri, 2015a) using geographic information system (GIS) tools.

Depth to water map

A GIS was used to create a continuous surface of the water table using an iterative finite-difference interpolation technique (Esri, 2015b) with measurements from 13 streamgages, 2 lake gages, 275 observation wells, 1 supply well, interpreted 10-foot (ft) contour intervals, and the coastline.

The land surface altitude, or topography, was obtained from National Oceanic and Atmospheric Administration (2016). The data were collected using light detection and ranging (lidar) and were used to produce a three-dimensional digital elevation model (DEM). The lidar data have a horizontal accuracy of 1.38 ft and a vertical accuracy of 0.40 ft at a 95-percent confidence level for the open terrain land-cover category. The DEM was developed jointly by the National Oceanic and Atmospheric Administration and the U.S. Geological Survey as part of the Disaster Relief Appropriations Act of 2013 (Pub.L. 113 2, H.R. 152, 127 Stat. 4). Land surface altitude is referenced to the North American Vertical Datum of 1988 (NAVD 88). On Long Island, NAVD 88 is approximately 1 foot higher than NGVD 29.

The continuous surface of the water table was adjusted for the vertical datum differences across Long Island. This surface was then subtracted from the land surface elevation (from the DEM) at the same location. The results are shown as a continuous depth to water-table map.

References Cited

Busciolano, Ronald, 2002, Water-table and potentiometric-surface altitudes of the upper glacial, Magothy, and Lloyd aquifers on Long Island, New York, in March April 2000, with a summary of hydrogeologic conditions: U.S. Geological Survey Water-Resources Investigations Report 01 4165, 17 p., 6 pl.

Como, M.D., Finkelstein, J.S., Simonette L. Rivera, Monti, Jack, Jr., and Busciolano, Ronald, 2017, Water-table and potentiometric-surface altitudes in the upper glacial, Magothy, and Lloyd aquifers of Long Island, New York, April May 2016: U.S. Geological Survey Scientific Investigations Map 3398, 4 sheets, scale 1:125,000, 6-p. pamphlet, https://doi.org/10.3133/sim3398.

Esri, 2015a, ArcMap 10.3.1: Redlands, Calif., Esri, software.

Esri, 2015b, Topo to Raster Tool: Redlands, Calif., Esri, software.

Lusczynski, N.J., 1961, Head and flow of ground water of variable density: Journal of Geophysical Research, v. 66, no. 12, p. 4247 4256.

National Oceanic and Atmospheric Administration, 2016, NCEI Hurricane Sandy digital elevation models: National Centers for Environmental Information, digital data, accessed January 8, 2016, at https://www.ngdc.noaa.gov/mgg/inundation/sandy/sandy_geoc.html

Smolensky, D.A., Buxton, H.T., and Shernoff, P.K., 1989, Hydrologic framework of Long Island, New York: U.S. Geological Survey Hydrologic Investigations Atlas HA 709, 3 sheets, scale 1:250,000.

Soren, Julian, 1971, Results of subsurface exploration in the mid-island area of western Suffolk County, Long Island, New York: Oakdale, N.Y., Suffolk County Water Authority, Long Island Resources Bulletin 1, 60 p.

Stumm, Frederick, 2001, Hydrogeology and extent of saltwater intrusion of the Great Neck peninsula, Great Neck, Long Island, New York: U.S. Geological Survey Water-Resources Investigations Report 99 4280, 41 p.