The Northwest River Watershed Protection District was adopted to prevent the pollution of public water supplies in accordance with City and Commonwealth codes and statutes. The Northwest River is one of the major drinking water supplies for the City. The drainage area for the river is about 161 square miles and includes all, or a majority of, the land and water areas that drain or flow toward the river, including portions located in the State of North Carolina. About 103 square miles are located in Chesapeake. Protection of this important public value is accomplished in part by establishing boundaries, setting policies, continuing the study of natural systems, and cooperating with other agencies and neighbors to effectively manage the regional impacts on the Northwest River.