Canvey Island risks to London and the Thames estuary area. It is proposed that the western side of Canvey is developed as a site which is either temporarily flooded at times of risk, or transformed into a permanent wetland. Developments in the 20th century have produced a marked contrast between the environments in the east and west of the island. The eastern half of the island is allocated to residential areas, the main public amenities and a small holiday camp and seafront, while the western half of the island is mainly farmland, marshes and industrial areas. The marshes in the west include
Severn Estuary the line between Lavernock Point and Sand Point is the Bristol Channel, which in turn discharges into the Celtic Sea and the wider Atlantic Ocean. The islands of Steep Holm and Flat Holm are located close to that line, in the middle of the estuary. Sometimes the term "Severn Estuary" is used to include the tidal upstream stretch between Gloucester and Aust. During the highest tides on the upper reaches of this stretch, the rising water is funnelled up the estuary into the Severn bore, a self-reinforcing solitary wave that travels rapidly upstream against the river current. The tidal range