Natural landscapes can slow, absorb, and filter water as it travels within a watershed towards its final destination -- in the case of the Cabin John Creek Watershed, water flows into the Potomac River, the Chesapeake Bay, and, ultimately, the Atlantic Ocean.  Historical land-use changes such as building and farming can have a detrimental effect on water quality, as meadows, wetlands, and woodlands are replaced by hardened and paved surfaces.  As rainwater run-off travels over hardened surfaces, it sweeps contaminants off the land and into water bodies.  This “non-point source pollution” is one of the most challenging threats to our water and environment today.  Careful land-use planning by local governments is one of the most important ways to protect watersheds from the potentially negative effects of land-use change.

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