White Rock Creek - Geology and Ecology

Geology and Ecology

The creek (and the lake it feeds) takes its name from the weathered-white Austin chalk (see chalk) which lines its bed and banks, thus revealing its place geologically within the Balcones Escarpment. In some places, this chalk becomes quite conspicuous as the creek cuts deep through canyon-like walls of rock and tree roots. Considered part of the Texas Blackland Prairie (locally White Rock Prairie) and Bottomland Forest ecosystems, the creek is host to multitudes of flora and fauna.

Wildlife include, mink, bobcats, coyotes, red fox, ducks, raccoons, skunks, opossum, gray squirrels, mice, rats and eastern cottontails. Where the banks are muddy, crayfish make their volcano-shaped homes. Many birds including Great Blue Herons, Great Egrets and Belted Kingfishers make their homes among and eat from the creek, and Double-crested Cormorants, American White Pelicans and American Coots often visit the lake. Herpetofauna include lizards, water moccasins, salamanders, red-eared sliders and common snapping turtles. The most common fish are sunfish, largemouth bass, white crappie and channel catfish.

The most common trees are Cedar Elm, Pecan and Green Ash. Forbs are encountered in the drier areas, whereas species more adapted to flooding are found where the banks are lower, such as Cottonwood, Black Willow, American Elm, Sycamore, Hackberry, Chinquapin oak, and Texas Buckeye. Berry-producing trees along the creek include Yaupon holly, Cherry laurel, Fruiting mulberry, Rusty blackhaw, and American sweetgum