The Susquehanna River

The Chesapeake Bay is essentially the Susquehanna River's valley floor. It is the tidal portion of the Susquehanna. The river and the Bay are two integral parts of one ecosystem. continued below

Twenty thousand years ago, during the last Ice Age, sea level was about 330 ft. lower than it is today. At that time, the Susquehanna flowed from the edge of the polar ice cap (in what is now north central Pennsylvania) down to the Atlantic. All of the rivers in what is now the Chesapeake drainage basin flowed into it. As the earth warmed up and sea level rose, the Atlantic backed up into the Susquehanna's valley floor, forming the Chesapeake Bay and the tidal portions of rivers like the Potomac and the Nanticoke. The Susquehanna's large drainage basin, or watershed, means the pollution that flows into Pennsylvania rivers and streams ultimately finds its way to the Chesapeake Bay. Many of Pennsylvania's waterways suffer from an overload of pollution from many different sources, including agriculture and stormwater.

The Bay-wide Chesapeake Clean Water Blueprint is the most significant effort to date to clean up our waterways and mitigate the effect of upstream pollution.