River Otter, Devon River Otter, Devon The River Otter rises in the Blackdown Hills just inside the county of Somerset, England near Otterford, then flows south for some 32 km through East Devon to the English Channel at the western end of Lyme Bay, part of the Jurassic Coast, a UNESCO World Heritage Site. The Permian and Triassic sandstone aquifer in the Otter Valley is one of Devon's largest groundwater sources, supplying drinking water to 200,000 people. The river's source is north of Otterford, where a stream feeds the Otterhead Lakes: and then through Churchstanton before entering Devon. The river flows through a
West Bay, Dorset a World Heritage Site which stretches for and includes most of the Dorset coastline. West Bay also lies within the Dorset Area of Outstanding Natural Beauty. West Bay is sited on deposits of river alluvium that indicate a former estuary. There are beaches and cliffs on either side of the harbour. The beaches were previously of a similar size—in terms of their seaward extent—but now East Beach is considerably larger, due to accumulation of finer sediment. East Beach is also designated a Site of Special Scientific Interest, and forms one end of Chesil Beach, a barrier beach which extends southeast