Numerous streams and swamps on gently rolling wooded plateaus dissect Chancellorsville, Wilderness, and Spotsylvania Courthouse Battlefields. Chancellorsville Battlefield lies on the divide separating the watershed of the Rappahannock River from the Po and the Ni rivers, and Spotsylvania Courthouse Battlefield lies between the drainage areas of the Po and the Ni rivers. The site of the Wilderness Battlefield is in the Wilderness Run drainage, which flows north into the Rapidan River. Streams in the park generally have good sustained flows. The availability of groundwater varies with the underlying rock formations, but in most areas of the two counties, an adequate supply of water may be obtained from springs and wells. Water quality depends on the chemical content of both underground and surface waters, the tidal influence of larger surface streams, and the degree of contamination from residential and industrial development.