South Thames Estuary and Marshes South Thames Estuary and Marshes South Thames Estuary and Marshes is a biological Site of Special Scientific Interest which stretches between Gravesend and the mouth of the River Medway in Kent. Part of it is a Nature Conservation Review site, Grade I, and part is a Royal Society for the Protection of Birds nature reserve. It is part of the Thames Estuary and Marshes Ramsar internationally important wetland site and Special Protection Area under the European Union Directive on the Conservation of Wild Birds. Over 20,000 waterfowl use this site, and some species are present in internationally important numbers. There
Exe Estuary on the west shore is the village of Dawlish Warren with its sand spit extending across the mouth of the estuary. Above this there are fewer settlements on the west shore, with just the villages of Starcross and Cockwood, both adjoining the lower portion of the estuary. The River Clyst also feeds into the estuary, just below Topsham. The River Kenn feeds into the estuary near Kenton. The soil is alluvial, derived from Devonian, Carboniferous and Permian rocks. The estuary is a Special Protection Area and SSSI. It is also a Ramsar site. The Exe Estuary is a site of