Introduction

The fractured-rock area of Maryland encompasses the region of the State west of the Fall Line, which is approximated by the Interstate 95 corridor. It includes the Piedmont, Blue Ridge, Ridge and Valley, and Appalachian Plateau Physiographic Provinces (fig. 1). Surface water and ground water are important and interconnected water sources in this area. Streamflow characteristics vary in response to different land use, geology, topography, soil, and other factors. Ground-water flow is quite localized, tending to be controlled by local watersheds. Water in this region moves down through the soil and decomposed rock (saprolite) and along joints, faults, and fractures in the underlying rock (fig. 2). Water availability depends upon the size of fractures as well as the interconnections between fractures.