In this subtitle the following words have the meanings indicated. “Patuxent River Watershed” means the land and water area from which all water drains either directly or indirectly to the Patuxent River. “Severn River Watershed” means the land and water area from which all water drains either directly or indirectly to the Severn River. “Watershed” means the Patuxent River Watershed and the Severn River Watershed.