Metadata: Well Location Points (Digitized) from the Minnesota Geological Survey's County Well Index (CWI)

Well Location Points (Digitized) from the Minnesota Geological Survey's County Well Index (CWI)

This page last updated: 07/18/2022
Metadata created using Minnesota Geographic Metadata Guidelines

Go to Section:
  1. Overview
  2. Data Quality
  3. Data Organization
  4. Coordinate System
  5. Attributes
  6. Distribution - Get Data
  7. Metadata Reference

Section 1: Overview

Originator:Minnesota Geological Survey and Minnesota Department of Health

Title: Well Location Points (Digitized) from the Minnesota Geological Survey's County Well Index (CWI)

Abstract: 'Cwilocs_nps' is a shapefile of well locations created from wells listed in the Minnesota Geological Survey's County Well Index (CWI) data base. Specifically, this coverage contains wells for which the locations have been verified by the Minnesota Geological Survey, the Minnesota Department of Health, or another agency, and a well location has been obtained either by digitizing the location from a USGS 7.5-minute quadrangle map, by field survey, or by GPS location. Attribute information about the wells includes key fields from County Well Index, including owner name, use type, location, aquifer, and water levels. Additional descriptive information about the wells is found in the full County Well Index data set.

The information in County Well Index was entered by the Minnesota Geological Survey from the Water Well Driller Log form, which was submitted by the well driller to the Minnesota Department of Health at the time the well was constructed. Submission of a Water Well Driller Log is a requirement of the Minnesota Water Well Construction Code, passed by the State Legislature in 1974. While the County Well Index does not represent all wells in the state, it is the single most complete listing of wells. Accuracy and completeness of CWI are discussed elsewhere in this document.

Purpose: The County Well Index (CWI) data base represents the most complete listing of wells in the state of Minnesota. The 'cwilocs_nps' point coverage has been created in order to provide a geographic reference for verified well locations which provides a tool to map well attribute data (such as stratigraphy, ground water levels, water chemistry, and water use), which are collected by MGS and other agencies. The RELATEID field (a field containing the Minnesota Unique Well Number) is the data field which provides the link between the Well Location GIS file and related data tables.

Time Period of Content Date:

Currentness Reference: File contains point locations for field-verified wells in County Well Index as of the date of the shapefile. The distribution version of the shapefile is updated periodically. See the readme file at the MGS ftp site for the exact date that the file was created.

Progress: In work

Maintenance and Update Frequency: Quarterly

Spatial Extent of Data: State of Minnesota

Bounding Coordinates: -97.5

Place Keywords: Minnesota, Statewide

Theme Keywords: geoscientificInformation, Well, Wells, Hydrology, Geology, Hydrogeology, Ground Water, Stratigraphy, County Well Index, CWI

Theme Keyword Thesaurus: ISO 19115 Topic Category

Access Constraints: None

Use Constraints: Acknowledgement of the Minnesota Geological Survey and the Minnesota Department of Health is appreciated in products derived from these data. Use should be consistent with the limits of the data set, as described in 'Locational Accuracy', 'Attribute Accuracy', 'Lineage', and 'Completeness' sections.

Contact Person Information: Jarrod Cicha, Subsurface Geologic Information Specialist
Minnesota Geological Survey
2609 Territorial Road
Saint Paul, MN  55114
Phone: 612-626-4108

Browse Graphic: None available

Associated Data Sets: 1. UNLOCS_NPS - a point GIS shapefile of all wells from CWI which do not have a good location. Point locations for these wells are derived by calculating the midpoint of the Public Land Survey (Township-Range-Section-Subsections) locations reported by the driller. These calculated locations vary in accuracy; see location accuracy code. Downloads of this file, '' are available at the same location as the '' file.

2. The MGS County Well Index (CWI) database, containing further information on well construction, stratigraphy, water levels, and water chemistry, is the primary associated data set. Data from many different agency data bases can be associated with the CWILOCS_NPS and UNLOCS_NPS shapefiles. Data is cross-referenced by Minnesota Unique Well Number (= RELATEID).

County Well Index datasets can be obtained from the Minnesota Geological Survey. For information, see
To download cwi data, go to

To search or view well locations and associated County Well Index information, go to the Minnesota Department of Health website, Minneosta Well Index at

Section 2: Data Quality

Attribute Accuracy: No statistical attribute assessment has been performed. Some attributes of the well, such as PLS location, depth, casing diameter, and driller record, may be checked if the well is in an area where geological studies are being done (for instance, a County Geologic Atlas or Regional Hydrogeologic Assessment by MGS). For wells in these areas, locations are verified, and the driller's description of the geologic layers encountered is converted by MGS into interpreted lithologic codes and geologic formation codes. Otherwise, no verification is done of information on the well driller log. Older data which was originally entered into the MGS 'WELLOG' data base had been transcribed onto a coding form from the Water Well Driller Log, and keypunch data entry was done twice on each record in order to identify errors.

Note that the well owner name and address represents the owner of the well AT THE TIME THE WELL WAS CONSTRUCTED. Subsequent changes in ownership are not recorded in CWI.

Well records which have PLS locations reported to six quarter sections and which have Aquifer, Lithology, and Stratigraphy fields filled in are generally those which have been field-verified and interpreted by the Minnesota Geological Survey.

Every well on the CWILOCS_NPS file (and in County Well Index) has a MINNESOTA UNIQUE WELL NUMBER, if available, or a W-SERIES number. These numbers are the key to linking data collected by numerous parties about the same well.

Logical Consistency:

Completeness: Only wells which are in the County Well Index database AND have been field-verified and digitized or GPS'd are included in this data set. This represents only a subset of wells in the state. Field-verification is most often done in conjunction with County Geologic Atlas or other geologic studies by the Minnesota Geological Survey. Areas which have had geologic studies done are likely to have more representation on this data set than other areas.

The County Well Index database associated with this GIS file represents known wells on the main statewide well index and DOES NOT represent all existing wells. Water Well Driller reporting has only been required since the State Water Well Construction Code was passed in 1974. Although older wells have been identified and added to the file in some areas, most pre-1974 wells are not represented. Since the law's enactment, driller compliance has been incomplete, although it is improving over time. Driller reporting of well location ranges from excellent to poor. Minnesota Department of Health well inspectors visit 10 to 25 percent of newly-drilled wells each year. For these wells, inspectors use GPS units as a means of obtaining higher-accuracy locational data. The Minnesota Geological Survey and the Minnesota Department of Health have been committed to keeping the CWI up-to-date by adding all newly-drilled wells to the database. Over time, both the number of wells and the locational and geological accuracy of the well information will be improved.

NOTE: As requested by the Minnesota Department of Health, this version of the located wells file does NOT include records for public supply wells. For public supply well information, see the contact listed on the Minnesota Department of Health's Minnesota Well Index webpage:

Horizontal Positional Accuracy: Positional accuracy varies by point. The shapefile WELLS generally represents wells which either have been field-verified by the Minnesota Geological Survey, plotted on 7.5-minute USGS quadrangle maps, and digitized, or have point locations based on a field survey or GPS. As such the horizontal positional accuracy is consistent with that of at least 1:24,000. The field GCM_CODE indicates the location method for the individual well point. A small percentage of wells (less than 1 percent) have not been field-verified. Wells which have an unverified driller-reported Public Land Survey location (township-range-section) which goes down to 6 quartersections (QQQQQQ or 12.5 meters on a side) have a point location calculated for them using the SECTIC program:
These locations are gradually being replaced with verified data.

Lineage: 1. Well Log Data Entry and Update (Minnesota Geological Survey and Minnesota Department of Health): Information recorded on the MDH Water Well Driller Log Form is entered into the County Well Index database by staff of the Minnesota Geological Survey and the Minnesota Department of Health. Wells in areas where MGS is doing geologic investigations (such as County Geologic Atlases or Regional Hydrogeologic Assessments) are field-verified by MGS staff, and well locations are placed on USGS 1:24,000 topographic paper map sheets. Periodically, well locations are digitized by MGS. Alternatively, some well locations are surveyed or obtained using GPS technology. Well inspectors are now equipped with GPS equipment and obtain high-quality locations for wells that they field-inspect. Point location information (in UTM Zone 15 NAD83) is stored by MGS in a 'WELLS' table in Microsoft Access.

2. CWILOCS_NPS point location shapefile creation (Minnesota Department of Health): MDH uses an Access location table and joins the 'C4IX' table from County Well Index (the main table containing well descriptive information) to create a CWILOCS_NPS shapefile in UTM Zone 15 NAD83. This CWILOCS_NPS shapefile is recreated daily at MDH from information in the location table and the CWI table C4IX.

3. Distribution version (Minnesota Geological Survey): On an as-needed basis the CWILOCS_NPS shapefile is re-posted to the MGS ftp site along with an updated version of the full County Well Index database, software, and viewing tools.

Section 3: Spatial Data Organization (not used in this metadata)

Section 4: Coordinate System

Horizontal Coordinate Scheme: Universal Transverse Mercator

UTM Zone Number: 15E

Horizontal Datum: NAD83

Horizontal Units: meters

Vertical Datum:

Vertical Units:

Depth Datum:

Depth Units:

Section 5: Attributes



SHAPE - Shapefile type (= 'point' for all records)

RELATEID - Key identification field for all well data:
* IF Minnesota Unique Well Number, then 00 + Minnesota Unique Well Number (8C)
* IF W-Series Number, then CC(County Code)+ W + 0 + original W-Series Number

(Note that in MGS and Mn Department of Health Databases, the Minnesota Unique Well Number has been converted from a 6-character to an 8-character field, to accomodate future growth in the system. Current Mn Unique Well Numbers still take up the right-most 6 characters, with two leading zeros.)

WELL_LABEL - Same as Minnesota Unique Well Number or W-Series Number, without leading zeros

TYPE - Point Type WW = water well
MW = monitoring well
EX = exploratory drillhole (mining)
SI = scientific investigation drillhole
SK = sinkhole

GCM_CODE - Geographic Method Code (identifies location accurcay).
*A = Digitized - scale 1:24,000 or larger
*B = Digitized - scale 1:100,000 to 1:24,000
*DN1 = Digitization (screen) - Map (1:24,000) - NOT Field checked
*DN2 = Digitization (screen) - Map (1:12,000) - NOT Field checked
*DS1 = Digitization (Screen) - Map (1:24,000)
*DS2 = Digitization (Screen) - Map (1:12,000)
*G3 = GPS Code Measurements (Pseudo Range) Differentially Corrected
*G6A = GPS Code Measurements (Pseudo Range) Standard Positioning Service Selective Availability On (averaged)
*G6O = GPS Code Measurements (Pseudo Range) Standard Positioning Service Selective Availability Off (averaged)
*I = GPS; accuracy 3 to 12 meters (+6 to 40 feet)
*PQ6 = Public Land Survey - QQQQQQ Section

GEOC_SRC - Geographic Coordinate Source.

GEOC_PRG - Program which created the geographic coordinate

GEOC_DATE - Original Geographic Coordinate Date

UTME - Universal Transverse Mercator (UTM) Easting value

UTMN - Universal Transverse Mercator (UTM) Northing value

UTM_ZONE - Universal Transverse Mercator (UTM) Zone

DATUM - Horizontal Datum (e.g., NAD27, NAD83). Data on this file is NAD83.

MGSQUAD - Minnesota Geological Survey Code for USGS 1:24,000 Quadrangle Map Sheet.

CONTACT_C - Code for the person who did the original geographic coding.

LASTUPD_D - Last geographic coordinate code date (if location has been adjusted).

LASTUPD_C - Code for the person who did the last geographic coordinate update (if location has been adjusted).

COUNTY_C - Minnesota state 2-digit county code.

UNIQUE_NO - Field contains Minnesota Unique Well Number, the traditional 6-character field padded with two leading zeros, or the W-Series number, represented as 'W' + Leading zero + W-Series number.

WELLNAME - Name of the well owner. Last name, first name for domestic well, Company name as commonly used for commercial wells. NOTE: this field reflects the name as it appears on the original Water Well Driller Log. The name is NOT updated when the property changes hands.

TOWNSHIP - Public land survey township number

RANGE - Public land survey range number

RANGE_DIR - Direction of the public land survey range number. Range directions in Minnesota are all West', with the exception of the eastern tip of Cook County.

SECTION - Public land survey section number. Legitimate values are 1 through 36.

SUBSECTION - Indicates from lrgest to smallest, the quarter, quarter-quarter, quarter-quarter-quarter, quarter-quarter-quarter-quarter section, and so on. The labeling of the subsections is as follows:
*A = northeast quarter
*B = northwest quarter
*C = southwest quarter
*D = southeast quarter

MGSQUAD_C - Minnesota Geological Survey code for the USGS 7.5-minute Quadrangle map on which the well is located.

ELEVATION - Elevation of the well in feet above mean sea level.

ELEV_MC - Code indicating how the elevation was determined.
*A = altimeter(+/- 1 foot)
*G = GPS (Global Positioning System/Satellite)
*H = GPS > 12M (<+- 40')
*I = GPS 3-12 M (+-10-40')
*J = GPS 1-3M
*K = GPS <=1M
*S = Surveyed
*T = 7.5-minute topographic map (+/- 5 feet)
*T2 = Calculated from 30-meter digital elevation model (DEM)

STATUS_C - Indicates the current activity status of the well.
*A = active
*I = inactive
*S = sealed
*T = temporarily sealed
*U = unknown

USE_C - Minnesota well use codes, as reported on the Water Well Driller Log.
*CO = Commercial
*DO = Domestic
*HP = Heat Pump
*IJ = Injection
*IN = Industrial
*IR = Irrigation
*LA = Lake Level Augmentation
*MD = Multiple Dwelling
*MU = Municipal
*MW = Monitor Well
*OB = Observation Well
*OT = Other (specify in remarks)
*PC = Community Supply (Municipal)
*PN = Public Supply/Non-community-transient
*PO = Pumpout Well
*PP = Public Supply/ Non-community-non-transiet
*PS = Public Supply/Non-community
*PZ = Piezometer
*RC = Recovery Well
*RW = Relief Well
*SI = Scientific Investigation
*TW = Test Well
*UN = Unknown

LOC_MC - Location Method Code- specifies how the well was field-located; this determines the accuracy of the well's identity and location and how useful the data recorded for the well are for certain applications.

LOC_SRC - Code indicating who did the location determination.

DATA_SRC - Code indicating source of the information. Code may consist of a driller's license number, an agency abbreviation, or a personalized abbreviation.

DEPTH_DRLL - Depth well was drilled in feet from the land surface.

DEPTH_COMP - Depth completed. Finished depth of the hole in feet; usually the same as depth drilled' but can be less if the hole was backfilled before finishing.

DATE_DRLL - Date that the well installation was completed.

CASE_DIAM - Well casing diameter, in inches.

CASE_DEPTH - Well casing depth, in feet.

GROUT - Indicated whether or not the well is grouted (Y = Yes, N = No).

POLLUT_DST - Distance in feet to nearest potential source of contamination; intended for rough estimates of close potential sources.

POLLUT_DIR - Direction to the nearest potential source of contamination referenced
in the pollution distance field. The direction codes are N,S,E,W,NE,NW,SE,SW

POLLUT_TYP - Code indicating the type for the potential source of contamination
*ASH = Ash
*BYD = Barnyard
*FDL = Feedlot
*IND = Industrial
*JSY = Junk/Scrap yard
*LDF = Landfill
*LIV = Livestock Watering
*O = Other
*OPD = Open Dump
*PES = Pesticides
*SDF = Septic Tank/Drain field
*STO = Storage areas
*TAN = Tanks
*VOC = Volatile organic compounds
*WAS = Waste pile
*BOW = Body of water
*OWL = Old/other well

STRAT_DATE - Date stratigraphy was interpreted.

STRAT_UPD - Date stratigraphy was updated.

STRAT_SRC - Agency which did the stratigraphic interpretation.

STRAT_GEOL - Initials of the geologist who did the stratigraphic interpretation.

STRAT_MC - Geologic interpretation method code.

DEPTH2BDRK - Depth to bedrock, in feet below land surface. (-999 indicates 'no data')

FIRST_BDRK - Code indicating the stratigraphic unit representing the first bedrock unit.

LAST_STRAT - Code indicating the last stratigraphic unit.

OHTOPUNIT - Code indicating the top stratigraphic unit to which the well is open.

OHBOTUNIT - Code indicating the bottom stratigraphic unit to which the well is open.

AQUIFER - Stratigaphic code used to identify the aquifer from which the well is drawing. 'MTPL' indicates multiple aquifer with the open interval top and bottom stratigraphic units given.

CUTTINGS - Flag indicating whether there are cuttings for this well.

CORE - Flag indicating whether a core sample was taken for this well.

BHGEOPHYS - Flag indicating whether a geophysical log exists for this well.

GEOCHEM - Flag indicating whether geochemical information exists for this well.

WATERCHEM - Flag indicating whether water chemistry information exists in CWI for this well

OBWELL - Flag indicating whether this well is part of the DNR's state ground water level observation network.

SWL - Flag indicating whether there is at least one static water level reading for this well

IGWIS - Flag indicating whether this well is part of the MPCA's IGWIS system.

INPUT_SRC - Code indicating who input this information into CWI.

UNUSED - This field is currently empty

ENTRY_DATE - Date of entry of well record into County Well Index.

UPDT_DATE - Date of last update to well record in County Well Index.

SWLCOUNT - (Using the date with the largest number of static water level measurement readings) Number of static water level readings.

SWLDATE - Date of Static Water Level Measurement (If multiple dates, uses the date with the largest number of static water level readings).

SWLAVGMEAS - Static Water Level Average Measurement (Depth to water) taken of the Static Water Level Date.

SWLAVGELEV - Static Water Level Average Elevation taken on the Static Water Level Date.

PWS - Code indicating whether the well is a Public Water Supply well

Table Detail:

Section 6: Distribution

Publisher: Minnesota Geological Survey and Minnesota Department of Health

Publication Date: 2017

Contact Person Information: Jarrod Cicha, Subsurface Geologic Information Specialist
Minnesota Geological Survey
2609 Territorial Road
Saint Paul, MN  55114
Phone: 612-626-4108

Distributor's Data Set Identifier: cwilocs_nps

Distribution Liability: Data is provided "as is" without any warranty whatsoever, including but not limited to any warranty as to performance, merchantability or fitness for any particular purpose.

The entire risk as to the results of the use of this data is assumed by the user. MGS and MDH are not responsible for any interpretation or conclusions made by those who acquire or use it. MGS and MDH shall not be liable for any direct, indirect, special, incidental, compensatory or consequential damages or third-party claims resulting from the use of this data, even if they have been advised of the possibility of such potential loss or damage. In states that do not allow the exclusion or limitation of incidental or consequential damages, this data may not be used.

Ordering Instructions: Download file CWILOCS_NPS.ZIP from Minnesota Geological Survey's public ftp site, in zipfile format. Readme file on site indicates the actual date of the data file.

NOTE: As requested by the Minnesota Department of Health, this version of the located wells file does NOT include records for public supply wells. For public supply well information, see the contact listed on the Minnesota Department of Health's Minnesota Well Index webpage:

Online Linkage: I AGREE to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process, link to a service, or provide more instructions. See "Ordering Instructions" above for details.

Section 7: Metadata Reference

Metadata Date: 07/18/2022

Contact Person Information: Nancy Rader, GIS Data Specialist
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street, Room 300
St. Paul, MN  55155
Phone: 651-201-2489

Metadata Standard Name: Minnesota Geographic Metadata Guidelines

Metadata Standard Version: 1.2

This page last updated: 07/18/2022
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