Discover the Oldest Man-Made Lake in Texas

Lake Austin is a part of the Colorado River; it begins below Mansfield Dam and is principally fed by the outflow of Lake Travis.The Colorado River, which means "red" or "reddish" river in Spanish.

Written by Kristen Holder

Updated: August 30, 2023

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While torrential rains do sometimes hit Texas, the state is better known for its long droughts. As a result, Texas has more reservoirs than any other place in the United States. There are around 7000 dams present in the state, but which one was built first? We’ll discover the oldest man-made lake in Texas now.

View from Lake Austin Dam of the Colorado River with concrete road bridge. Aerial landscape of water and roadway amid lush foliage of trees and sky on a sunny day.

View from Lake Austin Dam of the Colorado River.

©Jason Finn/

Lake Austin winds through the northeastern part of the capital city of Austin within Travis County.

What Is the Oldest Man-Made Lake in Texas?

The oldest man-made lake in Texas is Lake Austin. It was created in 1893 when a dam was built on the Colorado River, though the first dam failed in 1900.

It is a thin lake that appears riverine on a map. It’s maintained at a constant level by the outflows of other reservoirs along the same river system.

Originally called Lake MacDonald, Lake Austin is the latest iteration of a reservoir at its present location. The Austin Dam underwent a catastrophic failure, known as the Great Granite Dam Failure, as a result of a huge rainstorm in 1900. The damn failure caused a devastating flood.

The Tom Miller Dam, which stands today, was constructed in 1939 to keep the water impounded as it is seen today. Lake Austin, and the rest of the nearby reservoirs, were created for hydroelectric power generation, drinking water storage, and to impound floodwaters. While Lake Austin is maintained at a constant volume, other reservoirs in the immediate vicinity that support Lake Austin have levels that fluctuate wildly depending on current weather conditions.

Lake Austin holds around 20 thousand acre-feet of water, and its surface area is at least 1580 acres. The dam is around 1600 feet in length with a height of 85 feet.

Fall Colors at tom miller dam aerial drone view above fall landscape at Red Bud Island in Austin, Texas

The Tom Miller Dam, which stands today, was constructed in 1939 to keep the water impounded as it is seen today.

©Roschetzky Photography/

Lake Austin: Where Is the Oldest Man-Made Lake in Texas Located on a Map?

Lake Austin is in central Texas. It winds through the northeastern part of the capital city of Austin within Travis County. It is part of a system of 7 dams around Austin which includes Lake Austin, Lake Marble Falls, Lady Bird Lake, Lake Buchanan, Lake Travis, Lake LBJ, and Inks Lake.

Things to Do at Lake Austin in Texas

Most of the shoreline at Lake Austin is not open to the public as its on private land. However, lots of companies offer watercraft rentals including pontoon boats, party boats, jet skis, sailboats, and motorboats. Sailing, canoeing, and kayaking classes are offered by the Austin Parks and Recreation Department.

There are a handful of public parks and trails worth visiting if you’re trying to experience Lake Austin and you don’t know someone with private land butting up against the water. Some of the locations accessible by anyone are Fritz Hughes Park, Selma Hughes Park, Emma Long Park, and Mary Quinlan Park.

Swimming is a popular way to experience Lake Austin. However, it is illegal to swim more than 50 feet away from shore outside of designated swimming areas.

The water temperature hovers just above 70 degrees Fahrenheit even during the peak of the summer. Keep in mind that it is illegal to launch water balloons and other items at people in the water from the shoreline.

Anglers take advantage of Lake Austin, and all access fishing locations are found at the Loop 360 Bridge and the public parks. It’s important to remember that fishing off any bridge within city limits is illegal. However, the shore beneath the bridge is accessible to the public. There are two public boat ramps to launch vessels as well with one located below the Loop 360 Bridge and another at the Walsh Boat Landing.

Wildlife You’ll See At Lake Austin, Texas

Wildlife lives in Lake Austin. There are fish in the lake that capture the attention of fishers. Some species present in Lake Austin include largemouth bass, bluegill, redbreast sunfish, redear sunfish, flathead, and blue catfish.

Zebra mussels are present in Lake Austin which is problematic as they are invasive. All boaters must take precautions against transporting this species to other bodies of water in the state. Any boater that is caught with zebra mussels in their vessel is subject to punishment under state law.

what do mussels eat

Zebra mussels are present in Lake Austin which is problematic as they are invasive.


Triploid Grass Carp in Lake Austin

Triploid grass carp exist in Lake Austin. These fish are a special variety of grass carp that is incapable of breeding. They’re stocked in reservoirs and elsewhere to control invasive vegetation that is harming the native ecosystem.

These specific grass carp cannot breed because their eggs were purposefully shocked with cold or hot water right after they were fertilized. This causes an abnormality wherein the eggs retain an extra chromosome. This makes the eggs unviable which keeps the fish from reproducing.

It is now legal to keep any of the triploid grass carp that are caught. They were originally stocked to control the spread of the invasive hydrilla plant about a decade ago. However, the hydrilla is now under control but the carp are continuing to eat native vegetation.

There is no limit to the number of triploid grass carp that can be fished out of the lake. As long as you behead and gut the fish, you can take home as many as you’d like. There are also no size restrictions in place.

grass carp

Triploid grass carps are a special variety of grass carp (pictured here) that is incapable of breeding.

©Vladimir Wrangel/

Is Caddo Lake the Oldest Man-Made Lake in Texas?

No, Caddo Lake is not the oldest man-made lake in Texas. However, it is the only natural lake in Texas. It’s located in eastern Texas along the Louisiana border.

Its naturalness isn’t like most natural lakes as it was created by a log jam and not by the landscape. This log jam was over 100 miles in length and had existed for hundreds of years before being removed in the 1800s.

Today, there is a dam keeping the lake in its place. Without this dam making the lake deeper, Caddo Lake would be more of a swamp than the body of water that it is today. Despite this, it is still one of the most important wetlands in the United States.

The lake is primarily fed by the Big Cypress Bayou. This bayou is made of intermingling wetlands on the western boundary of Caddo Lake, and it contains the largest cypress tree forest in the world.

Caddo Lake

Caddo Lake is the only natural lake in Texas.

©Victoria Ditkovsky/

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About the Author

Kristen Holder is a writer at A-Z Animals primarily covering topics related to history, travel, pets, and obscure scientific issues. Kristen has been writing professionally for 3 years, and she holds a Bachelor's Degree from the University of California, Riverside, which she obtained in 2009. After living in California, Washington, and Arizona, she is now a permanent resident of Iowa. Kristen loves to dote on her 3 cats, and she spends her free time coming up with adventures that allow her to explore her new home.

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