The Texas Water Development Board (TWDB) has developed a statewide public water system service area mapping application called the Texas Water Service Boundary Viewer ("the Viewer") through a grant from the U.S. Geologic Survey (USGS) Water Availability and Use Science Program. While several statewide water system mapping applications exist, they do not necessarily represent the actual retail water service areas or include all public water systems (PWS). This mapping application strives to collect and provide the most up-to-date and best data available on the water service areas for all community PWS within Texas.

This material is based upon work supported by the U.S. Geological Survey under Cooperative Agreement No. G17AC00016. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.

Partnering with the Water User Survey program each year, water systems are asked to use the Viewer to update or verify their service boundaries to reflect current retail water service areas. The data collected within the Viewer is specifically used in the regional and state water planning process. The application will also be available to the public to view water service boundaries and related reports, including historical water use and Texas Commission on Environmental Quality (TCEQ) PWS information.

For more information, please read the Frequently Asked Questions (FAQ).

Common Definitions and Acronyms

Certificate of Convenience and Necessity (CCN)

The CCN obligates the retail water public utility to provide continuous and adequate service to every customer who requests service in that area.

Community public water system

A system for the provision of water to the public for human consumption through pipes or other constructed conveyances, which includes all uses described under the definition for drinking water. Such a system must have at least 15 service connections or serve at least 25 individuals at least 60 days out of the year (Texas Administrative Code, Title 30, Part 1, Chapter 290, Subchapter D (290.38(71)).


Public Utility Commission


Public Water System

Regional Water Planning Group

There are 16 planning groups across the state, each made up of 20 members that represent a variety of interests, including agriculture, industry, environment, public municipalities, business, and others. These planning groups adopt regional water plans which, once approved by the TWDB, are folded into the state water plan.

Retail service providers

An individual or entity that supplies potable water for human consumption.


Texas Commission on Environmental Quality


Texas Water Development Board


Texas Water Service Boundary Viewer

Wholesale service provider

An individual or entity that sells water to another utility for resale to the public, indirectly providing potable water.

Water Use Survey (WUS)

Annual survey to collect and maintain accurate information concerning the current use of water in the state administered by the TWDB.

Water User Group (WUG)

Planning unit used in the regional and state water plans.

Frequently Asked Questions

Why was the Water Service Boundary Viewer developed?

The TWDB developed the Viewer to facilitate the collection of digital maps for all community PWS retail water service areas in the state of Texas. There is currently no complete map of the 4,000+ PWS in the state, nor does the state require the collection of this essential information. Without this resource, it can be challenging to answer basic questions about public water supply. This map can aid in answering questions such as which PWS serves a population or supplies water to a specific address.

Through this mapping tool and cooperation from authorized PWS contacts, PWSs can update and verify service area boundaries for water systems throughout the state. This cooperation will make it possible to develop a high-resolution digital map of the most up-to-date PWS service area boundaries.

The Viewer was funded through a grant from the U.S. Geologic Survey (USGS) Water Availability and Use Science Program under Cooperative Agreement No. G17AC00016.

How does the TWDB intend to use these maps? Will they be used for the regional water planning process?

This application's primary purposes are:

  1. To collect accurate retail water service boundaries to better estimate and project utility population for the regional water planning process. This boundary viewer will also help in estimating rural population not served by any PWS (and solely relying on private wells).
  2. To develop a GIS database and reporting tool to improve the delivery of water data and PWS information collected by the State to the public as part of the USGS-funded Texas Water Use Data Workplan, which recommended priorities for the state’s water use data improvement.

The TWDB will be continually working to update, enhance, and associate relevant public water system information to the geographic boundaries.

What does water service boundary mean?

For the purpose of this application, a water service boundary is a boundary that includes all areas where a PWS currently serves retail customers, including residential, commercial, institutional, and industrial customers with retail connections to the water system.

Where does the draft boundary data come from?

The boundaries that preceded the Viewer were developed through a research grant for the TWDB in 2009. This layer was created using a conglomerate of data sources, including governmental and self-reported boundaries. The Viewer provides authorized water system personnel a starting point to verify or update boundaries for their retail water service areas. The last update date represents when the boundary was last submitted by the water system or reviewed by state representatives through the Viewer.

Who is responsible for developing and maintaining this tool?

The Water Use, Projections, & Planning Division at the TWDB is responsible for collecting and maintaining the boundary data in the Viewer.

How often will boundaries be updated?

Public water systems will be asked to update boundaries annually in partnership with the TWDB’s annual Water Use Survey program. The application will be open from January through July every year with the survey cycle. During that time, any boundary changes made by authorized PWS personnel will be updated through the application for the public to view after it is reviewed by the TWDB for known inaccuracies. Once the boundary editing period is closed, no changes will be made until the following year. Each system’s boundary will display the last updated (or PWS verified) date.

Why are there missing boundaries?

While the best effort was made to include a boundary for every system, some did not have enough information available to develop an initial boundary for each PWS personnel to review. As a result, the Viewer does not have initial draft boundaries for all PWS within the state. An authorized PWS personnel will be contacted to add a boundary during the editing period (January-July).

A PWS name search did not return a result.

While efforts have been made to include as many boundaries as possible, some may still not exist. The search feature matches text to entities with current boundaries. So if you searched for a PWS you know to be active in the search bar and no matches are found, then a boundary does not exist for that entity. You may also search by address, county, or city in case the PWS name you are searching is different from the one recorded with the TCEQ (the state agency responsible for PWS information).

Why do some water system boundaries appear to overlap?

While service areas should never overlap (i.e., only one utility can be serving each connection), some boundaries initially developed do overlap, even though an effort has been made to remove any user errors in overlapped boundaries. Authorized PWS personnel will have an opportunity to review and verify any overlapped boundary areas through this application.

When I viewed the Water Use Survey Report, all connection and usage data was 0?

A report displays all connection and usage data as 0 because that PWS has not returned a WUS for any previous year.

Whom should I cite when I use this data?

By using any data generated by the Viewer (via download or map viewer), you agree to cite: , Texas Water Development Board, and the date of download. By downloading and using the data, you understand the stated disclaimer included with the download.

Where can I learn more about drinking water systems and how they are regulated?

The Texas Commission on Environmental Quality Public Drinking Water section regulates the public water systems in the state of Texas. For more information about a PWS within the state, visit Texas Drinking Water Watch (DWW). DWW is a searchable database of drinking water quality, violations, and public water system’s compliance with state and federal regulations.

Whom do I contact if I have any questions?

If you have questions that are not addressed in this FAQ or the Help Guide, please contact us at WSBViewer@twdb.texas.gov or (512) 463-6867.