Ask an Expert: TxGIO’s map catalog offers free access to more than 600 high-quality maps Posted on April 9, 2025

Since 2010, the Texas Geographic Information Office (TxGIO) has developed and maintained traditional hardcopy thematic and reference maps for the Texas Water Development Board (TWDB). The map catalog includes various collections, ranging from basic county maps to those related to regional water supply and flood planning as well as groundwater and surface water management. The catalog underwent a comprehensive refresh In early 2025, which involved updating the GIS data, enhancing design elements and graphics, and adding new logos and information to reflect the agency's recent rebranding.

Erik O’Brian, who manages the TxGIO map catalog, explained that the catalog's primary goal is to provide free access to high-quality, accurate TWDB maps and geographic location information as quickly as possible for users. In this edition of Ask an Expert, O'Brian describes his work as a cartographer and GIS professional.

How do you describe your work in the Texas Geographic Information Office?

I usually tell people I am a cartographer and a geographic information system (GIS) specialist. I make maps at the Texas Geographic Information Office, a division of the Texas Water Development Board. Some people seem surprised and say, "People still want maps?" Then, I explain that I make real maps, many intended for print use. We, of course, produce many digital products as well. When people ask what GIS is, I point them toward the Google Earth mapping application as an example of GIS work to keep it simple and relatable.

Have you always been interested in maps?

I've been interested in maps, navigation, and traveling since I was a kid. My grandparents had a subscription to National Geographic, and my grandmother saved all the maps because she liked them and gave them to me.
So, I just grew up with all these cool National Geographic maps. I’ve also traveled a lot and appreciate both physical and cultural geography. I graduated from college with a geography degree.
In fact, I took the first GIS course offered by the University of Texas. We used data from TNRIS (now TxGIO) in our coursework, and I applied when a position came open in this department. I’ve now been with the agency for 20 years.

What is the TxGIO map catalog?

This resource is an online, freely downloadable map catalog mostly related to water features in Texas.
But it’s a vast catalog ranging from basic county maps to maps specific to the TWDB's work, like regional water supply and flood planning as well as groundwater and surface water management. The idea is to provide a no-cost mapping information resource for everyone.

What are the maps used for?

Anyone can access and use the map catalog. Our maps are used by the public, the Texas Legislature, other state agencies, and TWDB staff in other divisions. We get many requests from water districts and groundwater conservation districts. We also see real estate professionals and academics using our maps.

How are the maps made available?

The TxGIO website features downloadable PDFs, but if someone requests a specific file format, we can provide that. We also offer printing services if you want a hard copy of a map.

How often do you refresh the map catalog?

We just completed a major refresh of our map catalog, which is done every five years. We typically update the GIS data found in the maps and freshen up design elements and graphics.
In the latest refresh cycle, we incorporated the new TWDB and TxGIO logos to reflect the agency’s new branding.
In addition to each five-year major refresh, we update the maps as required by boundary changes or if a specific update is requested. We’re also looking ahead to a major update of the entire website. Once the new TxGIO website is online, we’re planning to provide more file download options.

What are some of the most popular maps?

Some of the most downloaded maps are regional water planning areas and big boundary maps, such as groundwater management areas and flood planning regions.
We also provide individual county maps for every county in the state, which are very popular. Many people like the Water for Texas map, which features several maps in one.

What does your work look like?

The Texas Water Development Board offers a lot of online map viewers and web-based maps that are highly utilized, but I'm still creating traditional maps mostly because there's still a demand for them.
We have more than 600 maps in the map catalog, and that’s quite a bit of information.
I work with mapping software that is designed to map GIS data. There’s no coding or scripting, just hand-drawn computer maps. I'm using a mouse and a keyboard to create the maps. My work is manual, and I prefer to design things independently and not use pre-loaded base maps. I always believe I can make it look better—it's my craft—I see it as art and hope it never disappears. I think it's also nice to have a traditional-looking map that you can print out and hang on your wall.

Can you share an example of a map-making challenge?

Many years ago, a director at the TWDB requested a large map, 8x8 feet. I had to figure out how to put it all together because our printer was not 8 feet wide.
The map also included many base map features like roads and lakes. I had to figure out how to make this giant map using only two pieces of paper. The work required moving around all these elements, which was very challenging. I basically had to create two separate maps and put them into one. I had to split a map down the middle and figure out how to fit all of that together. I was proud of that giant map because it was a significant challenge.

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