Kent coastline of Kent is continuously changing, due to tectonic uplift and coastal erosion. Until about 960, the Isle of Thanet was an island, separated by the Wantsum channel, formed around a deposit of chalk; over time, the channels silted up with alluvium. Similarly Romney Marsh and Dungeness have been formed by accumulation of alluvium. Kent's principal river, the River Medway, rises near East Grinstead in Sussex and flows eastwards to Maidstone. Here it turns north and breaks through the North Downs at Rochester, then joins the estuary of the River Thames as its final tributary near Sheerness. The Medway is
Salmon Falls River Salmon Falls River The Salmon Falls River is a tributary of the Piscataqua River in the U.S. states of Maine and New Hampshire. It rises at Great East Lake, Newichawannock Canal, and Horn Pond and flows south-southeast for approximately , forming the border between York County, Maine, and Strafford County, New Hampshire. The Salmon Falls River joins the Cochecho River near Dover, New Hampshire to form the Piscataqua River. It provides hydroelectric power at the New Hampshire towns of Milton, North Rochester, East Rochester, New Hampshire, Somersworth, and Rollinsford, and in Maine at Berwick and South Berwick. The final three