Where Does Texas Get Its Water?

Texas is the largest state in the contiguous United States with 254 counties and is home to around 29.1 million people. So how do this giant state and its many citizens get its water?

Texas gets its water from within its borders through groundwater and surface water sources. 56% of water comes from groundwater sources via nine major and 22 minor aquifers.

Texas’ surface water comes from 188 major reservoirs, 15 major river basins, and eight coastal basins. The majority of Texas’ drinking water comes from groundwater.

Austin Texas City River
Austin Texas City River - Texas View

Where Does Texas Get Its Water?

About 56% of Texas’ water comes from groundwater sources, about 42% comes from surface water, and 2% comes from treated, reused water.

Municipal

The water that comes from your tap is municipal water. It is water treated to make it potable (safe to drink) and used for drinking, cooking, cleaning, showering, and bathing. 

Around 75% of municipal water in Texas comes from groundwater sources, such as wells and aquifers. 

Agriculture

Water used for agriculture includes irrigation and the “watering of livestock” (water necessary to keep livestock). The majority of Texas’ water goes towards agriculture, using around 9 million acre-feet of water per year. 

Other Water Needs

The other major categories that use water in Texas are manufacturing, livestock, mining, and power. 

Surface Water vs. Groundwater

In any state, water supply goes into two categories: surface water and groundwater. Here is the difference between the two.

What Is Surface Water?

Surface water is water found on the Earth’s surface, such as lakes, rivers, streams, and even the ocean. Unlike groundwater, surface water is a direct subject to the water cycle. Evaporation of surface water leads to precipitation (rain), which replenishes the water supply. 

What Is Groundwater?

Groundwater is underneath the ground. Over time, water on the Earth’s surface flows into the tiny cracks and crevices of the ground and collects in aquifers. An aquifer is a space where water cannot travel down anymore, so the water accumulates in one spot. 

Texas Groundwater Sources

Most Texan water comes from groundwater sources, but where are these sources? Underground aquifers supply 62% of the state’s water. There are nine major aquifers and 22 minor aquifers in Texas that supply water. 

Major Aquifers of Texas

  • Ogallala: supplies the Texas Panhandle, primarily agriculture
  • Gulf Coast Aquifer: supplies the Gulf Coast area, primarily municipal
  • Edwards (Balcones Fault Zone): supplies San Antonio and Austin regions, primarily municipal
  • Carrizo-Wilcox: supplies 66 counties as it runs through a large portion of Central and Northeast Texas, split use between agriculture and municipal
  • Trinity: supplies 61 counties in North and Central Texas, primarily agriculture
  • Edwards-Trinity Plateau: supplies 40 counties in Central Texas, mainly agriculture
  • Seymour: supplies 25 Panhandle counties, primarily agriculture
  • Hueco-Mesilla Bolson: supplies El Paso and Hudspeth counties, primarily municipal
  • Pecos Valley: supplies 12 counties in West Texas, primarily agriculture

There are 22 minor aquifers of Texas scattered throughout the state. These are smaller and have lower water levels than the major aquifers. 76% of the water from aquifers goes towards irrigation in Texas. 

Texas Surface Water Sources

The majority of Texas’ surface water lies in reservoirs. Reservoirs are manufactured lakes that use a dam to collect and store fresh water. Texas has 188 major reservoirs, 15 major river basins, and eight coastal basins, all sources of surface water.

These surface water sources also serve an important function relating to Texas’ unpredictable weather. Texas has long periods of drought followed by sudden periods of flooding.

Many of Texas’ reservoirs were built to control flooding, and as time passed and water needs grew, they became a vital resource for replenishable freshwater.

River Walk San Antonio Texas
River Walk San Antonio - Texas View

Texas Water Frequently Asked Questions

Here are some common questions regarding water in Texas. 

Why does Texas have a water shortage?

The water infrastructure of Texas has had issues in the past, including the situation concerning the severe winter storms of 2021. Many municipal pipes, which deliver water to homes across Texas, were damaged during the storm. Widespread leaks led to some severe water loss. 

There have been pushes by individuals and groups to rebuild Texas’ water infrastructure to avoid an issue like that of 2021 in the future. The winter storms of 2021 severely affected the Texas water supply in 2022. 

How does Texas get clean water?

Potable water (meaning it’s safe to drink) in Texas comes from the same chemical and physical treatment process used in many other areas. There are five main steps to this treatment process. 

Coagulation

Positively charged chemicals go into the water. Dissolved solids and dirt carry a negative charge. The dissolved solids and dirt bind with the positively charged chemicals to create larger particles.

Flocculation

The water mixes after coagulation to form larger “flocs.” The heavier and larger particles contain dissolved solids and dirt.

Sedimentation

Larger particles sift out of the water during this step. Because the larger particle “flocs” is heavier than the water, they sink to the bottom. 

Filtration

The “flocs” are then filtered out of the clear water after settling to the bottom, eliminating dissolved solids and dirt from the clean water. There are several different filters applied to the water so that any size particle filters out. These filters are often sand, gravel, charcoal, and filter membranes. This process eliminates dust, unwanted chemicals, bacteria, parasites, and viruses.

Activated carbon is also typically used to eliminate any odors within the water. 

Disinfection

Chemical disinfectants, such as chlorine, chlorine dioxide, and chloramine, go into the water. These disinfectants eliminate bacteria, parasites, or germs that the physical process cannot kill.

You can read more about this process on the CDC’s site.

Who owns the water in Texas?

Texas owns all surface water in the state. The laws surrounding groundwater are more complicated. In general, water found on owned land can be pumped by the owner. Some conservation efforts are hoping to eliminate this unlimited pumping as water shortages in Texas become more common.

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