Several types of aquatic ecosystems are found at LLELA:

The Elm Fork of the Trinity River flows through LLELA, providing a rich corridor of riparian wildlife and vegetation. Herons, egrets, many species of ducks, kingfishers, beavers, and many other wildlife species depend on the river. LLELA’s stretch of the Elm Fork is even home to several imperiled freshwater mussel species, including the Texas Pigtoe and the Rock Pocketbook.

Wetlands are ecosystems covered with shallow water at least part of the year. Wetlands, in our area also referred to as marshes or swamps, have characteristic soils and vegetation which define them. They are extremely productive ecosystems: while wetlands cover only about ten percent of the Earth’s surface, they are the source of a quarter of the world’s productivity. Wetlands are particularly important for fish, amphibians, and many species of birds, for which they provide nurseries and nesting areas. They also help control flooding and clean the water by removing pollutants such as nitrates, phosphates, and heavy metals. These critical habitats can be found in several locations at LLELA, particularly just east of the Elm Fork, where LLELA is developing a boardwalk trail.

Ponds are found in many locations at LLELA. Before the land south of the Lewisville Dam was acquired by the U.S. government for flood control, what is now LLELA was divided into many parcels of land owned by farmers and ranchers. The ponds found on LLELA are old cattle tanks which once held drinking water for livestock. Now, they retain water for wildlife, including turtles, frogs, fish, beavers, and many other species.

Sloughs and creek drainages provide temporary water sources at LLELA. Both Office Creek and Stewart Creek provide temporary water sources for wildlife. There are also many sloughs on LLELA. A slough is a place where a creek used to run many years ago. Streams and rivers change their courses over long periods of time, often leaving low places that retain rainwater and floodwater. These become oxbow lakes or sloughs. Sloughs differ from ponds in that they often dry up for periods of time during the year.