About the River

At over 800 miles long, the Texas Colorado River is one of the longest rivers to start and end in the same state. (Note that it is NOT the same Colorado River that flows through Arizona, Utah, and other western states.) Because of its importance to our state’s economy, our environment, our industry, our agriculture, and especially our lives as Texans, it is truly the lifeblood of our state. Its headwaters begin in northwest Texas, and the river flows southeast, supporting many different communities and ecosystems and eventually emptying into the Gulf of Mexico at Matagorda Bay. Along the way, its reservoirs form the Highland Lakes, and it flows through downtown Austin, the fastest-growing metropolitan area in the country.

The river’s watershed

As you can see in this map, the Colorado River’s watershed is huge, including almost 15% of Texas. (A river’s “watershed” or “basin” is all the land that drains into that river.)

The Concho, San Saba, Llano, James, and Pedernales Rivers all empty into the Colorado, so their watersheds are considered part of the Colorado River’s watershed, too. Altogether, there are over 7,500 miles of creeks, streams, and rivers in our basin, and well over 2 million people live and work here. The Colorado’s watershed includes several major metropolitan areas, including Midland-Odessa, San Angelo, and Austin, and there are hundreds of smaller towns and communities as well. Many communities, like Austin, rely on the Colorado River for 100% of their municipal water.

Water quality & quantity

The long-term vitality of the Colorado River depends on how clean and healthy it is (water quality) and also on how much water remains in the river, even in times of drought (water quantity).

Did you know that the most common pollutant in American waterways is dirt? Water quality can be impacted negatively by a number of things, almost all of which are connected to human activity. When you see a plastic bag or wrapper blowing along the street, rain will likely carry it into a storm drain and from there into a local creek, and it will eventually end up in the Colorado River. This visible pollution is unsightly and damaging to aquatic ecosystems. Fertilizers, weed killers, and pesticides all wash off yards and fields and into our waterways as well. This invisible pollution is harder to spot, and over time it can build up in our waterways with devastating results. (For instance, click here for a current list of golden algae blooms in the Colorado River being investigated by Texas Parks & Wildlife.) Dirt is an especially common pollutant, usually washing in from land that has lost its natural vegetative cover or blowing in on the wind. Dirt can also come from construction sites, though most builders put measures in place to prevent this. Chemicals dumped from an industrial site is an example of “point source” pollution, because it comes from a specific source. Fertilizer run-off is an example of “non-point source” pollution because it can come from many places at once — making it harder to prevent. For more information on what Texas is doing about non-point source pollution in our waterways, click here.

Many people ask, “Will we run out of water?” They are very concerned about water quantity in the Colorado River, and with good reason. With explosive population growth in many parts of our river’s basin, the demand for water is increasing steadily. Not all of the river’s water goes for municipal uses like tap water, watering lawns, and fire hydrants; huge amounts of our river’s water also support manufacturing, cooling systems for power plants, and irrigation for farms. And believe it or not, one of the single biggest “loss factors” of water in the Colorado River is evaporation from the Highland Lakes! Also, some of the river’s water is pumped to other places: Both Corpus Christi and Round Rock receive water that is piped in from the Colorado River, even though those towns are outside the Colorado’s watershed. It’s especially important that we think about our ecosystems as well: Fish, insects, and other aquatic life are threatened when water levels drop. At the mouth of the Colorado River, a complex, environmentally sensitive, and economically valuable system of bays, estuaries, and marine life would collapse without adequate flows coming out of the river. The most effective long-term solution is to educate both adults and children about river stewardship, water conservation, and aquatic science. At the Colorado River Alliance, we are proud that, through water-conservation pledges, our programs help leave over 20 million gallons of water in the river every year!

Floods & Droughts

Flooding and droughts are nothing new to the Colorado River basin. Because of our geographic location, huge storms can converge here, causing catastrophes like the 2018 floods. It’s not just recent storms, or storms coming up from the Gulf of Mexico: In 1936, a single storm system dumped 30 inches of rain just north of San Angelo. As the Colorado River and its tributaries pass through the rocky Highland Lakes area, these waterways converge and speed up, sometimes resulting in flash floods. In fact, Central Texas is one of the most flash-flood-prone areas of the United States, and the Highland Lakes reservoirs were built specifically for flood control, to protect the growing number of homes and businesses along the river. Visit texasflood.org for information about floods and for helpful resources in the event of a flood near you.

2011 was the single worst year of drought in our state’s history, and the infamous drought of the 1950s is still considered the “drought of record” for a drought that lasts multiple years. Did you know that, if the drought of the ‘50s hit Texas today, over 300 municipalities across the state would run out of water? Drought is a serious threat in the Colorado River basin, and like flooding, it is all the scarier because of its unpredictability. Not only does drought impact water quantity, because less rain runoff is flowing into our waterways, but it also impacts water quality, as low flows and higher water temperatures change the chemistry of the water. (For instance, as water levels drop and flow rates decrease, the amount of oxygen dissolved in the water can decrease sharply, stressing or killing aquatic life.)

The Colorado River basin has always experienced floods and droughts, but changes to our climate are steadily making both the floods and droughts that we experience more frequent and more severe. What’s more, data from tree rings tell us that our region has experienced “megadroughts” multiple times in past centuries. The threat of megafloods and megadroughts is real, and it is growing. The need for long-term strategic thinking and public discussion of water issues — like our Barstow Speaker Series and Colorado River VIP Tour has never been greater.

Problems: Who to call

Emergencies: Call 911

Boating safety

Hotline for pollution and fish kills: (512) 389-4848 or (281) 842-8100

Lake Patrol for Lake Austin and Lady Bird Lake

Ask us a question

Do you have a question about the Texas Colorado River? Ask us! If we don’t know the answer, we’ll help you find someone who does.

Resources for educators

Colorado River Education Kits
The Colorado River Alliance would like to bring the River to you! We have two TEKS aligned take-home kits designed for 4th and 5th-grade classroom settings. These kits are an excellent supplement or alternative for those schools who are unable to visit us at the Redbud Center and are FREE OF CHARGE. Currently, we offer kits covering topics on wetlands, watersheds, water properties, and the water cycle. See below for a short synopsis of each kit.

Kits are reserved on a first come first served basis and may be picked up at the Colorado River Alliance’s office anytime during business hours. Ideally, kits will not be utilized for more than one week’s time. Please click here for our online registration form. 

Wetlands Exploration
The Wetlands Exploration Kit helps fourth or fifth graders discover the importance of wetlands and the ecological roles they play.  This hands-on activity allows students to be creative while using the scientific method to explore wetlands.  The lessons in this kit provide students with the opportunity to brainstorm wetlands, build their own wetlands, and create a “living food web.”

Watershed Wonders
The Watershed Wonders Kit helps allows students to discover how watersheds work and their importance. Students will work with small watershed models, explore their watershed online, and learn about water quality in small groups.

Water Properties 
The water properties kit is designed to help students visualize and understand the chemical make-up and unique properties of water. This kit will provide hands-on modeling of surface tension and adhesion and an active game to understand polarity.

Water Cycle in Action
The Water Cycle in Action Kit allows educators to demonstrate the water cycle right in their own classrooms.  This activity enables students to observe the different components of the water cycle; to learn about the effects pollution has on the water cycle, and to learn about the distribution of fresh water on Earth.  The lessons in this kit provide students with the opportunity to brainstorm about the water cycle, observe a live demonstration of the water cycle, and build density columns representing the freshwater distribution on Earth.