skip to the content of this page Arizona's Official Website Arizona Department of Water Resources
Arizona Department of Water Resources Arizona's Official Web Site
Securing Arizona's Water Future
Ask us a question...Click for site mapClick to use the ADWR DictionaryDepartment Contact InformationADWR CalendarSend page to printerPlace a Bookmark hereSend a link to this pageDecrease font sizeIncrease font size

Comprehensive Well Inventories


ADWR performs comprehensive well inventories near WQARF sites in Arizona as part of the Department of Environmental Quality (ADEQ) WQARF Remedial Investigations process.  A single comprehensive source of information about wells in Arizona does not exist.  The well inventories entail a compilation of well information from multiple data sources, reviewing and matching well records, and field verifying the wells to ascertain their status.  The wells are photographed, construction data are recorded, and the location and elevation of the wells are measured using Global Positioning System (GPS).  The information collected from the well inventory is used to update ADWR and ADEQ databases.


Data Sources for Comprehensive Well Inventories


Various databases that have been maintained by several state agencies for a variety of purposes are used in the comprehensive well inventory.  The databases often do not have common field, such as a well registration number.  Described below are several major databases available in Arizona that contain information on wells and are used in the well inventories.

 rain drop  Arizona State Land Department Database

The first statewide registration of wells began in 1945, when all irrigation wells that pumped greater than 100 gallons per minute in Critical Groundwater Areas had to be registered with the Arizona State Land Department (ASLD).  This database is referred to as the WELLS-35 database because the ASLD began attaching 35-prefix numbers to wells sometime during the 1970s.  The ASLD well records were transferred to ADWR in 1980.  WELLS-35 well records can be viewed and downloaded at ADWR’s imaged records database.  This database is static; no records are added to this database.

 rain drop  ADWR GroundWater Site Inventory Database

The ADWR GroundWater Sites Inventory (GWSI) database is a scientific database that includes groundwater levels and limited groundwater quality data from designated index wells across the state.  The GWSI database was acquired from the United States Geological Survey in 1983.  The ADWR Field Services Section is continually adding new wells, groundwater level data, and select water quality data to this database.  The GWSI database can be accessed online on the ADWR website.  Click here to search and download data from the GWSI database.

 Rain Drop  ADWR Well Registry Database

When the Groundwater Management Code was passed by the Arizona Legislature in 1980, all existing wells within the state were required to be registered with ADWR.  A process for registering all new wells was also created.  Any person drilling a well in Arizona must first file a Notice of Intent (NOI) to Drill a Well with ADWR.  The well registration data for existing and new wells are stored in a database commonly referred to as the WELLS-55 database.  The WELLS-55 database theoretically contains information on every well in the state; however, not all wells have been registered. 

The WELLS-55 database contains owner-provided information when the owner submits a NOI to Drill a Well to ADWR.  The well data are generally not field verified.  As such, well information is not always accurate or complete.  Once a well is completed, a driller’s report with as-built data is filed and those data are entered into the WELLS-55 database.

Well records in the WELLS-55 database are represented by a paper file and an imaged record of that file.  Imaged records for all wells in an inventory project area are reviewed for information not included in the electronic database that will assist in determining the location and status of the well.  Records are added to the WELLS-55 database daily.

 Rain Drop  Arizona Department of Environmental Quality (ADEQ) Water Quality Database

The Water Quality database contains water quality, well construction, and water level information for thousands of wells, and other related data collected by the various ADEQ programs.  Water quality data are added to this database frequently.

 Rain Drop  University of Arizona (U of A) Well Records

ADWR obtained a collection of approximately 3,700 paper copy well records from the U of A that include wells that were drilled prior to the 1950s (mostly from 1908 through 1940).  Data contained within these records included general well construction data, driller’s logs, water levels, and particle size logs and aquifer test data for a number of wells.   The ADWR Water Quality Unit has converted these paper records into an electronic format.  These records can be viewed and downloaded at ADWR’s imaged records database.

 rain drop   Other Data Sources

Additional sources of well data used in the comprehensive well inventories are consultant reports, and ADEQ’s WQARF, VRP and LUST files for sites with project areas.  Site maps of well locations, well inventories conducted by independent parties and other useful data assist in locating and identifying wells in the field.


Comprehensive Well Inventory Process




1.  Well information is compiled from WELLS-55, GWSI   Wells 35, the ADEQ Groundwater Quality database, the U of A well database if applicable, and other available well databases.  The well records are reviewed and a cross-tab link is created between the databases for matching records.  This allows ownership, well construction, water level, and water quality data to accessed.



Well information is recorded into an electronic database using a field-based computer application.


Field Verification of a well

Documenting well information for a monitoring well located in central Phoenix.  A photograph, GPS measurement, and construction data are recorded.

2.  A combined database of all well records is created and ADWR attempts to field verify every well.  Field verification is the most important component of the comprehensive well inventory.  Wells visited are photographed, available construction information such as well diameter and well pad dimensions and ownership information are recorded, and the location of the well is measure with a handheld GPS device.  ADWR returns to each located well to get a Real Time Kinematic (RTK) GPS measurement, if allowed by the well owner.  The RTK survey also captures accurate elevation data.

well during the RTK measurement

Location of a domestic well near the Vulture Mill WQARF site being measured by the Geophysics/ Surveying Unit using RTK.    


3.  When a well is determined to be unregistered (not listed in the WELLS-55 database), an administrative late registration record is prepared.  This does not officially register the well, but provided a means to link data in other databases.  Administratively registered wells are given a WELLS-55 registration number in the 700,000 series.   Inclusion in the WELLS-55 database with a 700,000 registration number does not make the well a “well of record” for other legal purposes.  The well owner must formally register the well to make the well a legal well of record.


4.  Actively maintained databases such as the GWSI are updated to include the WELLS-55 registration number and other construction or location information.  The well inventory data are shared with ADEQ to allow updating of the Water Quality database.


Well Inventories at WQARF Sites


Below is a listing of comprehensive well inventories conducted at WQARF sites by the Water Quality Unit.  Fourteen comprehensive well inventories have been completed.  One well inventory is currently in process.  The table lists the inventories and shows the number of wells located, when the inventory was performed, and the area of the project.  Note that the information collected during each well inventory is current up to the date of the inventory.


                             rain drop  Phoenix Metropolitan Area

WQARF Site(s)

# Wells Located

Fiscal Year(s)


(square miles)

Site Map Link

Estes Landfill




Estes Site Map

Motorola 52nd Street

(Former East Washington)




EW Site Map

West Central Phoenix

(includes 5 WQARF sites)




WCP Site Map

South Mesa




SM Site Map

West Van Buren




WVB Site Map

Central Phoenix

(includes 3 WQARF sites)




 CP Site Map

East Central Phoenix

(includes 6 WQARF sites)

In progress



 ECP Site Map


                                      rain drop  Tucson Metropolitan Area

WQARF Site(s)

# Wells Located




(square miles)

Site Map Link

Miracle Mile




MM Site Map

7th Ave. and Arizona Ave.




Park-Euclid Site Map





BP Site Map

Shannon Road-Rillito Creek /

El Camino del Cerro




SR Site Map


                                  rain drop  Statewide Areas

WQARF Site(s)


# Wells Located




(square miles)

Site Map Link

Payson PCE /
Tonto and Cherry





TOP Site Map

Tyson Wash

La Paz




TW Site Map

Vulture Mill





 VM Site Map

20th Street and Factor





 20th Site Map


Hydrology Division Navigation Links

Use the above links to navigate the Hydrology Division