Harford County is in northeastern Maryland along the upper western shore of the Chesapeake Bay. The county is approximately 440 square miles with a population of more than 255,000 (based on the 2010 Census). There are three incorporated municipalities: the City of Aberdeen, the City of Havre de Grace, and the Town of Bel Air, the county seat. In 1977, a development envelope was established along the Route 40 and Route 24 corridors to direct growth into areas served by public water and sewer. More than 80% of the county’s population resides within this area.
Aberdeen Proving Ground, a 60-square-mile federal facility, is at the southern end of the county. While on the Chesapeake Bay, much of Harford County’s bay shoreline is occupied by APG and inaccessible to the general public. Harford County is divided into four major river basins – the Bush River Basin, the Gunpowder River Basin, the Lower Susquehanna River Basin, and the Upper Western Shore Basin. There are approximately 1,200 miles of streams within the county.
There are two major dams in Harford County. Conowingo Dam, built in 1928 on the Susquehanna River above Havre de Grace, is used to produce hydroelectric power for over 40,000 people daily. Atkisson Dam, on Winters Run in the Bush River Basin, was constructed in 1942 by the Army as a drinking water reservoir for Aberdeen Proving Ground. It was never used for this purpose and today is in the middle of Harford Glen Environmental Education Center.