SDETrims.DBO.hydro_GMA

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What does this data set describe?

Title: SDETrims.DBO.hydro_GMA
Abstract: Groundwater management areas in Texas.
Supplemental_Information:
(* Dataset was edited in May 2006 by Mark Hayes. Original boundary line between GMA 11 and GMA 14 (the Trinity river section in the northern part of GMA 11) was replaced by the Walker County line boundary.)

GMA 11 and 14 boundary changed Mr. Lloyd Behm, Bluebonnet Groundwater Conservation District General Manager, sent a letter requesting that the Walker County boundary for Groundwater Management Area 14 be changed to reflect the county boundary as stated in the Chapter 356 preamble.

TWDB staff examined the Chapter 356 preamble to determine if Mr. Behm's observation that our official GMA map contradicts our preamble. His contention was that Walker County is completely in GMA 14 and no other GMA. The original TWDB GMA map shows the boundary as including Walker County in both GMA 11 and GMA 14.

Preamble Language Item 9 in the preamble and rule adopting 31 TAC Chapter 356, Sections 356.21 and 356.23 states that, "The common boundary between GMAs 12 and 14 as initially proposed followed the western and northern extent and occurrence of the Gulf Coast aquifer as delineated in the Board's major aquifer map. As a result of comments, the Board modifies a portion of the boundary to generally coincide with the northern and western boundaries of Washington and Grimes counties and the northern boundaries of Walker, San Jacinto, Polk, Tyler, Jasper, and Newton counties. However, the original proposal continues where the upper extent of the aquifer that reaches into Brazos County remains, tying Washington County with Grimes County by following the aquifer boundary through Brazos County. As a result of these changes Washington, Grimes, Walker, San Jacinto, Polk, Tyler, and Jasper Counties are wholly within GMA 14 along with a small portion of Brazos County. This change is made because of the nature of the aquifer boundary in this area is transitional, therefore a political subdivision boundary is equally as appropriate as a boundary based on hydrology. In such cases, the Board chooses to honor political subdivision boundaries, including existing districts and counties, to better facilitate the administration and coordination of groundwater management in the area."

The confusion possibly resulted because the Board's first version of the GMA boundaries was based solely on aquifer boundaries, whereas the revised version included political boundaries and honored some requested changes. Effectively, the original map version split Walker County between three GMAs, 11, 12, and 14. The revised map version corrected the county splits between GMAs 12 and 14, but neglected to change specifically the Walker County boundary between GMAs 11 and 14.

Results The contention that Walker County is only in one GMA was a reasonable conclusion. The phrase describing the boundaries indicate that Walker County is ". wholly within GMA 14." We presented the proposed change to the TWDB Board in the November Board meeting and they approved the change. We updated the map, without revising the paragraph, and justified the change by acknowledging that it is implicit that the paragraph intended to include Walker County wholly within GMA 14 as written in the preamble .

  1. How should this data set be cited?

    REQUIRED: The name of an organization or individual that developed the data set., REQUIRED: The date when the data set is published or otherwise made available for release., SDETrims.DBO.hydro_GMA.

    Online Links:

    • \\NEPTUNE\GIS\Recommended_GIS_data\State_and_Regional_Mapping_Data\Administrative_Boundaries\Groundwater_Management_Areas\Groundwater_Management_Areas.mdb

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -106.646210
    East_Bounding_Coordinate: -93.507813
    North_Bounding_Coordinate: 36.500381
    South_Bounding_Coordinate: 25.837217

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: REQUIRED: The 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.

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • G-polygon (16)

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Resolution: 0.000010
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates

  7. How does the data set describe geographic features?

    SDETrims.DBO.hydro_GMA

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    PERIMETER

    Shape_Leng

    F_AREA

    OBJECTID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    GMA

    SDETrims.DBO.hydro_GMA.AREA

    Shape.area

    Shape.len

    Anno_1_3

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

Why was the data set created?

To establish 16 Groundwater management areas within the State of Texas. Areas are comprised of parts of aquifer lines, county boundaries, rivers, PGMA lines and GCD boundary lines.

How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    (process 1 of 9)
    Dataset copied.

    Data sources used in this process:

    • E:\Projects\Groundwater\Groundwater_Management_Area_Boundaries\GMAs_As_Of_October_8_2002\groundwater_management_areas_final

    (process 2 of 9)
    Dataset copied.

    Data sources used in this process:

    • E:\Gis Data\Shapefiles\groundwater_management_areas\Groundwater Management Area Boundaries

    (process 3 of 9)
    Dataset copied.

    Data sources used in this process:

    (process 4 of 9)
    Dataset copied.

    Data sources used in this process:

    (process 5 of 9)
    Dataset copied.

    Data sources used in this process:

    • C:\MyGIS\GISTemp\GMA_temp\gma_poly_dd

    (process 6 of 9)
    Metadata imported.

    Data sources used in this process:

    • L:\Projects\Rio\Ts\GIS Projects and files\MAP files\groundwater_management_areas.shp.xml

    (process 7 of 9)
    Metadata imported.

    Data sources used in this process:

    • L:\Recommended_GIS_data\State_and_Regional_Mapping_Data\Administrative_Boundaries\Groundwater_Management_Areas\metadata.xml

    (process 8 of 9)
    Dataset moved.

    Data sources used in this process:

    • L:\Recommended_GIS_data\State_and_Regional_Mapping_Data\Administrative_Boundaries\Groundwater_Management_Areas\groundwater_management_areas_dd

    (process 9 of 9)
    Dataset moved.

    Data sources used in this process:

    • L:\Recommended_GIS_data\State_and_Regional_Mapping_Data\Ground Water\Majors\groundwater_management_areas_dd

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

  5. How consistent are the relationships among the observations, including topology?

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints: None

  1. Who distributes the data set? (Distributor 1 of 1)

    Texas Water Development Board
    c/o Mark Hayes
    Mapping Coordinator
    1700 N. Congress Ave.
    Austin, Texas 78701
    United States

    (512) 936-0828 (voice)
    mark.hayes@twdb.state.tx.us

  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 20-Aug-2007
Metadata author:
REQUIRED: The organization responsible for the metadata information.
c/o REQUIRED: The person responsible for the metadata information.
REQUIRED: The city of the address., REQUIRED: The state or province of the address. REQUIRED: The ZIP or other postal code of the address.

REQUIRED: The telephone number by which individuals can speak to the organization or individual. (voice)

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.8.6 on Mon Aug 20 13:56:54 2007