The Serpentine Lakes are considered an important wetlands area. They form part of a major palaeo-drainage system, an ancient and inactive drainage system from the Palaeozoic era. The surface of the lake normally consists of dry clay, silt and sand, and is covered with a salty crust. The sediment is mostly quartz arenite. The lakes form the main channel of the palaeo-drainage system. Other channels are covered by dunes and are not well defined.