GAM technical memo by Cindy Ridgeway Texas Water Development by eminems

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									GAM technical memo 01-05
by Cindy Ridgeway
      Texas Water Development Board, Groundwater Availability Modeling
      (512) 936-2386
      cindy.ridgeway@twdb.state.tx.us
      June 26, 2001

PRE-1980 PUMPAGE INFORMATION

        The purpose of this document is to describe pre-1980 pumpage information available
        from the Texas Water Development Board. The following Microsoft® Excel tables of
        pumpage information have been developed for further analysis:
            •   Historical Summary_1974and1977 (county level only)
            •   RawDataMUN_WaterUseSurvey_Pre1980
            •   RawDataMFG_WaterUseSurvey_Pre1980 (includes some manufacturing, power, and
                mining)
            •   MUN_LinkedWithWellData_Pre1980
            •   MFG_LinkedWIthWellData_Pre1980
            •   GAM_countypop_1900to1990

        These tables include pumpage information for the Carrizo-Wilcox, Edwards BFZ,
        Edwards Trinity Plateau, Gulf Coast, and Ogallala aquifers. The tables should first be
        queried for the aquifer and/or counties being modeled.

        The TWDB started its water use survey in 1955 to better estimate municipal and
        industrial water use. Surveys in the early years, between the mid-1950s and early 1980s,
        were limited and infrequent. Caution is advised while analyzing this information because
        incomplete information was collected during this time. The tables in this subset were
        developed in the same manner as those referenced in GAM Technical Memo 01-03.
        Exceptions are noted as follows:

Historical Summary_1974and1977 Table:
        This table was designed in a manner similar to the HistoricalSummary_County-
        Other,PWR,MIN,IRR,STK table previously provided. However, it does not contain the
        following fields: Basin num, Basin name, and Partial. Prior to 1980, county-level
        summaries, statewide, were estimated for 1974 and 1977, respectively. Even though the
        1974 summary was originally described at the basin level, the data was retained and
        accessible in the TWDB database at the county level only. The data has not been
        distributed to account for regional splits or basin components. A comment field has been
        added to this table to flag counties that are split by regional boundaries. These counties
        include Young, Smith, Henderson, Trinity, Polk, Wharton, Hays, and Williamson. The
        table deviates from the HistoricalSummary_County-Other,PWR,MIN,IRR,STK table in
        that county-other is combined with cities and reported as total municipal and
        manufacturing information has also been included. It should also be noted that Water
        User Group (WUG) IDs and sequence information have not been provided for the
        municipal category since this is a many-to-one relationship.

RawDataMUN_WaterUseSurvey_Pre1980 Table:
      This table was designed in a manner similar to the
      RawDataMUN_WaterUseSurvey_”aquifer name” table previously provided. The
      “remarks” field has also been omitted from this table to avoid duplication of records since
      this field, in many cases, had a many-to-one relationship. Please note that a new field,


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        “comments”, has been included to flag records that were not properly indexed to
        automatically dsistribute pumpage amounts when the water user group was split by
        region, county, or basin boundaries. In addition, if a city does not appear in this dataset
        for a particular year it may not have been surveyed for that particular year.

        For developing rural domestic (county-other) estimates for the years that a summary was
        not developed, comparison of this data to total county population and applying a gallons-
        per-year-per-capita value to the non-reported municipal use is one suggestion. County
        wide population estimates can be located in the “GAM_countypop_1900to1990” table.
        Since the “GAM_countypop_1900to1990” table does not delineate cities, a field called
        “totalconn” (total connections) has been provided in the
        “RawDataMUN_WaterUseSurvey_Pre1980” table. The consultant should determine a
        “persons-per-connection” (normal range 2.5 to 3.2), deduct the population in “cities”, and
        apply the gallons-per-year-per-capita value to the remainder.

RawDataMFG_WaterUseSurvey_Pre1980 Table:
      This table was designed in a manner similar to the
      RawDataMFG_WaterUseSurvey_”aquifer name” previously provided. All fields
      referenced in the previous table have been provided. Again, this table does not contain
      all manufacturing, power, or mining water use that may have occurred in a particular
      year, it only contains the data collected from those responding to the survey.

MUN_LinkedWithWellData_Pre1980 Table:
      This table was designed in a manner similar to the MUN_LinkedWithWellData_”aquifer
      name” previously provided. As noted above, this table also includes fields called
      “totalconn” and “comment”. In addition, a field entitled “date_drilled” has been provided at
      the end of the table. Twenty-eight percent of the records did not return at least one well
      location. Some of the records missing spatial locations may be addressed by the TWDB
      special survey project currently underway for the post 1980 data set. However, many of
      these entities may no longer be in business or may have merged with another company
      or operation. If further information that would require contacting the entity is desired
      please contact the TWDB project manager of your respective modeling area. At a
      minimum, the data should be analyzed using the procedure outlined in GAM Technical
      Memo 01-03, sections 1.01 through 1.07.

MFG_LinkedWithWellData_Pre1980 Table:
      This table was designed in a manner similar to the MFG_LinkedWithWellData_”aquifer
      name” previously provided. In addition, a field entitled, “date_drilled” has been provided
      at the end of the table. Eighty-nine percent of the records did not return at least one well
      location. Some of the records missing spatial locations may be addressed by the TWDB
      survey for the post 1980 data set. However, many of these entities may no longer be in
      business or may have merged with another company or operation. If further information
      that would require contacting the entity is desired, please contact the TWDB project
      manager of your respective modeling area. At a minimum, the data should be analyzed
      using the procedure outlined in GAM technical Memo 01-03, sections 1.01 through 1.07.

GAM_countypop_1900to1990
        This table contains U.S. Census population totals for counties by decade from 1900 to 1990.




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