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
Zumbro River The North and South forks join about east of Mazeppa in southwestern Wabasha County, and the Zumbro River flows eastwardly through Wabasha County, through the Richard J. Dorer Memorial Hardwood State Forest and past Zumbro Falls, Hammond, Millville and Kellogg. It flows into the Mississippi River about east of Kellogg. Some species of fish that can be found in the Zumbro River near Rochester include Green Sunfish, Rock Bass, Smallmouth Bass, Largemouth Bass, Common Carp and Creek Chub, Channel Catfish, Blue Catfish, Northern Pike. Zumbro River The Zumbro River is a tributary of the Mississippi River in the Driftless Area