How Deep Is the San Antonio River?

Written by Rob Amend
Updated: August 6, 2023
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Key Points:

  • The San Antonio River is 24 feet at its deepest point and 2 feet at its most shallow.
  • The 240-mile-long river includes five separate ecoregions – each with its own flora and fauna.
  • There are 15 miles of hiking, running, and biking trails along the San Antonio River Walk as well as kayaking and fishing options on many portions of the river.


The San Antonio River finds its source in San Antonio, Texas, about 4 miles northwest of downtown. Springs from the Edwards Aquifer join to create the waterway. At 240 miles, it is the 11th longest river in Texas. It is also the largest urban ecosystem in the United States. So, how deep is the San Antonio River? Sometimes running as shallow as 2 feet, the river reaches 24 feet at its deepest.

The Founding of San Antonio

Spanish explorers arrived in 1691 on the feast day of St. Anthony of Padua and named the river and the region for the saint. In 1718, Spain created a mission and an outpost, making it the oldest municipality in Texas for over 300 years. It has been part of the Spanish Empire, the Mexican Republic, the Republic of Texas, the United States, the Confederate States, and the United States again.

The Alamo before sunrise

The Alamo was one of the first Spanish missions in the area now known as San Antonio.

© Meland

Ecology of the San Antonio River

The 240 miles of the San Antonio River includes five ecoregions. The Edwards Plateau consists of oak, mesquite, and grasslands. The Post Oak Savannah has bands of oak forests made of post and blackjack oak. Prairie tallgrasses like big bluestem and Indiangrass populate the Blackland Prairie. The South Texas Plains are covered in thorny trees and scrub, including mesquite, acacia, and prickly pear. Finally, the Gulf Prairies and Marshes have sandy dunes, beaches, estuaries, marshes, and wetlands.

These ecoregions host a variety of native wildlife. Throughout the river basin, fish include largemouth bass, flathead catfish, longear sunfish, and red shiners. Reptiles and amphibians include comal blind salamanders, bullfrogs, Rio Grande leopard frogs, diamondback water snakes, snapping turtles, red-eared sliders, and Texas river cooters. Raccoons, white-tailed deer, armadillos, rabbits, collared peccaries, and opossums flourish around the river. You can see double-crested cormorants, whooping cranes, mallards, ospreys, belted kingfishers, and snowy egrets in the brush, trees, and along the shores.

Cormorant neotropic perched on a branch in Denman Estate Park San Antonio

The San Antonio River has several waterfowl, including the cormorant, that depend on its waters.

©Raul Baena/

What to Do on the San Antonio River

San Antonio is one of the United States’ major cities, and there are plenty of things to do. In addition to the culture provided by a major city, there are parks and the river itself.

There are miles of hiking, running, and biking trails along the San Antonio River Walk—15 miles of them! There are also kayaking and fishing options on many portions of the river. You can explore the San Antonio Missions and enjoy art in the museums within the city. You can also participate in the annual photography contest (River Clicks) to win recreational packages. There is primitive camping at Helton Nature Park and birdwatching with the Mission Reach Avian Study.

Dog Park Series - San Antonio Header

There is much to do on the San Antonio River, including its famous River Walk.

©Sean Pavone/

About the San Antonio River Walk

The centerpiece of any experience of San Antonio and its river is the San Antonio River Walk. The river is a cherished feature of San Antonio, and there have been several initiatives to preserve and improve it. The culmination of all of these efforts is the River Walk, a stretch of the river located a level down from the automobile street, running between two parallel sidewalks and winding through restaurants, shops, museums, and the five Spanish colonial missions at the heart of the original colonial outpost from the 1700s. This city park forms a unique pedestrian “street” and is a popular tourist destination.

Where is the San Antonio River Located on a Map?

The San Antonio River begins in San Antonio, ending 240 miles later near the Gulf of Mexico.


Though it never runs deeper than 24 feet, the San Antonio River is the heart of the San Antonio region. An essential feature of the San Antonio River is that it carries water to the Gulf of Mexico. It also provides recreational opportunities for the city.

The photo featured at the top of this post is © Terri Butler Photography/

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About the Author

Rob Amend is a writer at A-Z Animals, primarily covering meteorology, geology, geography, and animal oddities. He attained a Master's Degree in Library Science in 2000 and served as reference librarian in an urban public library for 22 years. Rob lives in Cincinnati, Ohio, and enjoys spending time with his family, hiking, photography, woodworking, listening to classic rock, and watching classic films—his favorite animal is a six-foot-tall rabbit named Harvey.

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