The Lavaca River flows through south-central Texas, originating in southwestern Kerr County and winding southeast for 432 miles through a drainage area of 6,061 square miles before joining the Colorado River system. This river system varies dramatically from the steep limestone Hill Country prone to flash flooding in its upper reaches to the flat, rolling terrain of the lower basin. The Lavaca River is part of the broader Guadalupe River Basin and Lavaca-Guadalupe Coastal Basin, characterized by spring-fed perennial streams in the upper regions and brackish tidal influences in the lower sections near the coast. The river supports diverse aquatic habitats ranging from swift rocky runs over limestone substrates in the headwaters to slower-moving sections with sandy and silty bottoms downstream.