The following may further clarify the matter. Consequently, what happens in the Brandywine affects the health of both the Christina Watershed and the Delaware River Basin. To add to the confusion, the EPA has delineated somewhat different shaped watersheds than some states. But do not be distracted by semantics and arguments concerning the finer points of watershed delineation. The point is that what happens in a given watershed has important consequences for the health of other watersheds.
Watersheds fit together like pieces of an interdependent puzzle.
Satellite data courtesy of Ray Sterner of the Johns Hopkins Advanced Physics Laboratory from the Color Landform Atlas of the United States . This is accomplished in several ways. However, this presentation will focus upon the use of topographic maps for delineation. However, the general steps are outlined below, followed by a series of maps that illustrate an actual delineation at various scales, thus allowing the viewer to see topographic details that drive the delineation process. To more easily follow the following steps it may be wise to either print the maps linked below or open them up in separate windows so that they can be examined as each point is read.