Frequently asked questions about the MGS County Well Index

  1. What is the County Well Index?
    The County Well Index (CWI) is a database system developed by the Minnesota Geological Survey (MGS) and the Minnesota Department of Health (MDH) for the storage, retrieval, and editing of water-well information. The database contains basic information on well records (e.g. location, depth, static water level) for wells drilled in Minnesota. The database also contains information on the well log and the well construction for many of the wells.

  2. Is this information available to anyone?

  3. What kind of computer do I need to run CWI?
    A computer running Windows 95, 98, ME, NT, 2000, or XP with a minimum of 64mb ram and 350mb of available disk space. It will run on a machine with a 166mhz processor, but, as might be expected, a faster processor will deliver a more satisfactory experience.

  4. Is there a Macintosh version of CWI?
    No, although it may be possible to get it to work with a Windows emulator such as SoftWindows running on the Mac. This has not been tested.

  5. Who currently uses CWI?
    CWI is used by a variety of state and local agencies, by private companies interested in ground-water related issues, and by educational institutions for research and educational purposes.

  6. Does the database include all wells drilled in Minnesota?
    No. CWI is by far the most comprehensive database of water-well information available, but contains only information for wells for which a log is available. We estimate this to be about ten percent of all wells drilled. Most of the records in CWI are for wells drilled since 1974, when the water-well construction code required drillers to submit records for wells drilled in the state to the MDH. CWI does contain data for some records obtained by the MGS through the cooperation of drillers and local government agencies for wells drilled before 1974.

  7. How often is the information updated?
    The database is updated continuously by the MGS and the MDH. CDs with the database and retrieval software (cwi4VIEW) developed by Fuliao Li of MDH are available for purchase. The data on the CDs are updated quarterly. The same information contained on the CD is also available on the MGS ftp site ( ). The raw database (without cwi4VIEW) and a shapefile containing locations for those wells that have had their locations field verified are updated frequently.

  8. How can I find out if my well is on the database?
    If you have a copy of CWI, you can search the database based on Public Land Survey (township, range, and section) or by well address or owner's name. Keep in mind that the owner's name is (usually) that of the owner at the time the well was drilled. Address searches also are often not successful since small inconsistencies or errors in entry of the address or the search criteria will cause the search to fail. If you do not have CWI, and are in the Twin Cities area, you can stop by the MGS and a staff member will help you search for your well. The Environmental Services office or Soil and Water Conservation District office or other county office in your county may also have CWI available and may be able to help you with database searches also.

  9. What else can CWI be used for?
    cwi4VIEW provides a variety of ways to select, or sort, and list or report information about wells. A group of wells can be selected based on a single criteria of combination of criteria. For example, a user can select all wells in a certain township, range, and section, that encounter bedrock within 50 feet of the surface, or wells that pump water from the Jordan aquifer. Once the wells have been selected the information can be viewed on-screen, the list printed, or reports generated for individual well records.

  10. Does the database include information in addition to that on the well record?
    Yes. CWI can store static water level measurement data from any source for a particular well. In this way, the data can be examined for changes or trends over time. A CWI record also contains flags indicating whether geophysical information is available for that well or if information about the well is available in other state databases. Multiple, general "remarks" may be entered into the database offering an opportunity to capture information about the well that may not fit in the fields designed for the well record.

  11. Are only water-well records included?
    For the most part, yes. Some exploratory boreholes along with records of monitoring wells are being added to CWI.

  12. Can I edit the data?
    No. CWI is provided to the public as a viewable database. However, we are always trying to improve the quality of the database, so we would appreciate hearing of errors found in the database (please include the unique number of the well along with the information you believe to be in error, and email to ).

  13. Is it possible to get hard copy reports of the data?
    Yes. cwi4VIEW includes a report writer that can generate a printed list of a group of selected wells or full reports for each selected well log.

  14. Is CWI compatible with other database software?
    CWI is currently storage as an Access database. Access provides a number of export formats that allow transfer of the data to other database software.

  15. Is CWI compatible with geographic information systems (GIS)?
    Yes. A shapefile containing locations and the main CWI table for wells that have been field located and digitized is provided on the CDs and on the MGS ftp site. Many GIS software packages are capable of reading the shapefile format. Free software from the Minnesota Land Management Information Center (LMIC) is available ( ) that can convert the PLS information (township, range, section, subsection ) contained in CWI to Universal Transverse Mercator (UTM) coordinates, which would allow plotting of well locations that are not included in the shapefile. If this is done, however, care should be taken in making assumptions or interpretation based on these locations since the accuracy is often not very good.

  16. How can I order CWI?
    Stop by the MGS Map Sales office (2609 West Territorial Rd., St. Paul) or call 612-626-2969 and place an order with Map Sales. Please allow 2-3 business days to process your order.

  17. How much does it cost?
    CWI is available to the private sector for $15.00 plus tax and shipping. The CD contains the complete CWI data for the entire state as well as the associated shapefile.

  18. How can I receive updates?
    As mentioned above, new versions of the CWI CD are created quarterly. For most of the state, the dataset does not change very rapidly (i.e. not many wells are drilled) and annual update may be satisfactory. In some high-growth areas, however, more frequent updates may be desired. The basic procedure is to simply purchase a new CD when an update is desired and, when the update is received, uninstall the previous version before installing the new version. Also, as mentioned previously, update are available through the MGS ftp site ( ).

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