Accurate maps of streams could aid in more sustainable development of Potomac River watershed

University of Maryland Center for Environmental Science: Where a stream ends is clear, but where it begins can be more difficult to discern. Researchers from the University of Maryland Center for Environmental Science have developed a new method to solve this problem, resulting in a new map of the Potomac River watershed stream network that significantly improves the information needed for assessing the impact of urbanization on aquatic ecosystems.

“For the first time, we have an accurate representation of where streams once flowed through major urban areas of Baltimore and Washington, D.C. and where streams currently flow through forests,” said the study’s lead author Dr. Andrew Elmore of the University of Maryland Center for Environmental Science's Appalachian Laboratory. “This information is critical for quantifying the impact of urbanization on aquatic ecosystems.”

Urbanization results with the land being covered by hard, or impervious, surfaces that prevent soil from absorbing water and pollutants. Water instead moves quickly as "runoff," picking up large amounts of sediment and pollution along the way and delivering it to streams and major bodies of water, such as the Chesapeake Bay. This leads to decreased water quality that can impact the health of vegetation, wildlife, and humans that come into contact with it.

The researchers developed a high-resolution map of streams in the Potomac River watershed and five smaller Maryland watersheds, an area that spans from the Appalachian Mountains to the Chesapeake Bay and includes the metropolitan areas of Baltimore, Maryland, and Washington, D.C. The maps show streams that still flow through forests and fields, as well as predicts the location of streams that have been buried through development and agricultural use....

Hagen Creek in Maryland, US Fish & Wildlife Service