File Geodatabase Feature Class

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US, Aquifers


This layer contains the major underground aquifers found in Texas. This polygon file was designed for medium to small scale thematic mapping and analysis.



The spatial data were obtained from the Texas Water Development Board (TWDB) and are current as of 2007. Attributes were modified to include only aquifer name, code, rock name and type, and area information. The coordinate system of this data is WGS 1984.

The areal extent of the aquifers, as shown in this map layer, represents

the area in which a named aquifer is the shallowest of the principal

aquifers. These aquifer areas are not necessarily the only areas in which

ground water can be withdrawn, for two reasons: 1) The aquifers shown may

have a larger areal extent than is represented here. The boundaries in

this map layer generally represent an interpretation of the surface

location (outcrop), or near-surface location (shallow subcrop) of the

uppermost principal aquifer for the area. An aquifer may extend beyond

the area shown, but be overlain by one or more other aquifers, and (or)

low-permeability material. 2) There may be areas of water-bearing

surficial material not shown in this map layer. Major alluvial aquifers

that occur along main watercourses are not shown. Significant

unconsolidated sand and gravel aquifers, that are not indicated in this

map layer but are important sources of water, may occur locally in

glaciated regions. The user of this map layer is advised that to get

complete information regarding areas that serve as sources of water, more

information about surficial aquifers needs to be obtained, particularly in

glaciated areas.

This map layer was constructed by combining data created for or from the

regional GWA chapters. Minor aquifers that are important local sources of

water were mapped in some regions, so the regional maps in the GWA may

show more detail than this map layer. The data were reviewed, adjusted,

and published based on new information provided by national, State, and

local scientists. The juxtaposition of regionally mapped aquifers has led

to some instances where an aquifer outcrop or shallow subcrop is bounded

by a State line. This is a result of the regional mapping and national

categorization methods used and is not meant to imply a hydrogeologic

change coincident with a State boundary.


Center for Geospatial Technology, Texas Tech University
US Department of the Interior

Use limitations


West  -160.236068    East  -66.939560
North  49.385628    South  18.915496

Scale Range
Maximum (zoomed in)  1:5,000
Minimum (zoomed out)  1:150,000,000

ArcGIS Metadata 

Topics and Keywords 

*Content type  Downloadable Data


*Title US_Aquifers_USDOI

Presentation formats* digital map

Resource Details 

Dataset languages* English (UNITED STATES)

Spatial representation type* vector

*Processing environment Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS

Center for Geospatial Technology, Texas Tech University
US Department of the Interior

ArcGIS item properties
*Name US_Aquifers_USDOI
*Location file://\\cgstdb\CGSTGeognet\Geognet\Geognet2014\USLayers2014\US_Aquifers\USAquifers.gdb
*Access protocol Local Area Network


Geographic extent
Bounding rectangle
Extent type  Extent used for searching
*West longitude -160.236068
*East longitude -66.939560
*North latitude 49.385628
*South latitude 18.915496
*Extent contains the resource Yes

Extent in the item's coordinate system
*West longitude -160.236068
*East longitude -66.939560
*South latitude 18.915496
*North latitude 49.385628
*Extent contains the resource Yes

Spatial Reference 

ArcGIS coordinate system
*Type Geographic
*Geographic coordinate reference GCS_WGS_1984
*Coordinate reference details
Geographic coordinate system
Well-known identifier 4326
X origin -400
Y origin -400
XY scale 999999999.99999988
Z origin -100000
Z scale 10000
M origin -100000
M scale 10000
XY tolerance 8.983152841195215e-009
Z tolerance 0.001
M tolerance 0.001
High precision true
Left longitude -180
Latest well-known identifier 4326
Well-known text GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433],METADATA["World",-180.0,-90.0,180.0,90.0,0.0,0.0174532925199433,0.0,1262],AUTHORITY["EPSG",4326]]

Reference system identifier
*Value 4326
*Codespace EPSG
*Version 8.2.6

Spatial Data Properties 

*Level of topology for this dataset  geometry only

Geometric objects
Feature class name US_Aquifers_USDOI
*Object type  composite
*Object count 4514

ArcGIS Feature Class Properties
Feature class name US_Aquifers_USDOI
*Feature type Simple
*Geometry type Polygon
*Has topology FALSE
*Feature count 4514
*Spatial index TRUE
*Linear referencing FALSE


Distribution format
*Name File Geodatabase Feature Class


Details for object US_Aquifers_USDOI 
*Type Feature Class
*Row count 4514

*Data type OID
*Width 4
*Precision 0
*Scale 0
*Field description
Internal feature number.

*Description source

*Description of values
Sequential unique whole numbers that are automatically generated.

Field Shape
*Alias Shape
*Data type Geometry
*Width 0
*Precision 0
*Scale 0
*Field description
Feature geometry.

*Description source

*Description of values
Coordinates defining the features.

*Data type String
*Width 40
*Precision 0
*Scale 0

*Data type Integer
*Width 4
*Precision 0
*Scale 0

*Alias AQ_NAME
*Data type String
*Width 60
*Precision 0
*Scale 0

*Alias AQ_CODE
*Data type Integer
*Width 4
*Precision 0
*Scale 0

Field Shape_Length
*Alias Shape_Length
*Data type Double
*Width 8
*Precision 0
*Scale 0
*Field description
Length of feature in internal units.

*Description source

*Description of values
Positive real numbers that are automatically generated.

Field Shape_Area
*Alias Shape_Area
*Data type Double
*Width 8
*Precision 0
*Scale 0
*Field description
Area of feature in internal units squared.

*Description source

*Description of values
Positive real numbers that are automatically generated.

Metadata Details 

*Metadata language English (UNITED STATES)

Scope of the data described by the metadata* dataset
Scope name* dataset

*Last update 2015-01-05

ArcGIS metadata properties
Metadata format ArcGIS 1.0
Standard or profile used to edit metadata ItemDescription

Created in ArcGIS for the item 2014-09-03 09:02:31
Last modified in ArcGIS for the item 2015-01-05 10:14:54

Automatic updates
Have been performed Yes
Last update 2015-01-05 10:14:12

FGDC Metadata (read-only) 


Citation Information
OriginatorREQUIRED: The name of an organization or individual that developed the data set.
Publication DateREQUIRED:  he date when the data set is published or otherwise made available for release.
Geospatial Data Presentation Formvector digital data
Online Linkage\\Macnetapp\ATLAS\data_received\wrd\aquifers\aquifrp025.mdb

                            REQUIRED: A brief narrative summary of the data set.
                            REQUIRED: A summary of the intentions with which the data set was developed.
Time Period of Content
Time Period Information
Single Date/Time
Calendar DateREQUIRED:  he year (and optionally month, or month and day) for which the data set corresponds to the ground.
Currentness Reference
                            REQUIRED: The basis on which the time period of content information is determined.
ProgressREQUIRED: The state of the data set.
Maintenance and Update FrequencyREQUIRED: The frequency with which changes and additions are made to the data set after the initial data set is completed.

Spatial Domain
Bounding Coordinates
West Bounding Coordinate-160.236053
East Bounding Coordinate-64.566162
North Bounding Coordinate49.385620
South Bounding Coordinate17.674693

Theme Keyword ThesaurusREQUIRED: Reference to a formally registered thesaurus or a similar authoritative source of theme keywords.
Theme KeywordREQUIRED: Common-use word or phrase used to describe the subject of the data set.

Access Constraints
                        REQUIRED: Restrictions and legal prerequisites for accessing the data set.
Use Constraints
                        REQUIRED: Restrictions and legal prerequisites for using the data set after access is granted.
Native Data Set Environment
Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 3; ESRI ArcCatalog

Spatial Reference 

Horizontal Coordinate System Definition
Latitude Resolution0.000001
Longitude Resolution0.000001
Geographic Coordinate UnitsDecimal degrees

Geodetic Model
Horizontal Datum NameNorth American Datum of 1983
Ellipsoid NameGeodetic Reference System 80
Semi-major Axis6378137.000000
Denominator of Flattening Ratio298.257222

Vertical Coordinate System Definition
Altitude System Definition
Altitude Resolution0.000010
Altitude Encoding MethodExplicit elevation coordinate included with horizontal coordinates

Entities and Attributes 

Metadata Reference 

Metadata Date2003-09-30
Metadata Contact
Contact Information
Contact Organization Primary
Contact OrganizationREQUIRED: The organization responsible for the metadata information.
Contact PersonREQUIRED: The person responsible for the metadata information.
Contact Address
Address TypeREQUIRED: The mailing and/or physical address for the organization or individual.
CityREQUIRED: The city of the address.
State or ProvinceREQUIRED: The state or province of the address.
Postal CodeREQUIRED: The ZIP or other postal code of the address.

Contact Voice TelephoneREQUIRED: The telephone number by which individuals can speak to the organization or individual.

Metadata Standard NameFGDC Content Standards for Digital Geospatial Metadata
Metadata Standard VersionFGDC-STD-001-1998
Metadata Time Conventionlocal time