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
Columbia River Estuary Columbia River Estuary The Columbia River Estuary is an estuary and a bay on the Oregon–Washington border and the Pacific Coast of the United States. If the Columbia River Estuary is defined by the region that experiences ocean tides, then the estuary extends up the Columbia River to Bonneville Dam and up the Willamette River to Willamette Falls (south of Portland at Oregon City, Oregon). If the estuary is defined by the geographic land form or by the inland extent of salinity, then the estuary extends only as far as Welch Island. The downstream end of the estuary is the