Harford County is located along the upper western shore of the Chesapeake Bay. The Chesapeake Bay is the largest estuary. The Bay is approximately 200 miles long and varies from about 4 miles wide near Aberdeen to 35 miles wide near the Potomac River. While the average depth of the Bay is 21 feet, most of the Bay is much shallower. Only a few areas of the Bay reach 100 feet in depth.
The Chesapeake Bay Watershed encompasses six states: New York, Pennsylvania, Delaware, Maryland, West Virginia and Virginia, and the District of Columbia (Washington,D.C.) and covers 64,000 square miles. There are currently 15 million people living in the Chesapeake Bay Watershed and this is expected to increase by 2.6 million by the year 2020.