Canvey Island barriers spanning Benfleet Creek to the north and East Haven Creek in the west. The drainage system consists of sewers, culverts, natural and artificial dykes and lakes which feed seven pumping stations and gravity sluices that discharge the water into the Thames and creeks. Four of the discharge sites are "high flow" stations capable of discharging 600 litres of water per second at any tide level. The levels within the system are managed by a further five "low flow" pumping stations. The Environment Agency's Thames Estuary 2100 flood defence plan includes Canvey Island as one site for alleviating the flood
Dee Estuary Dee Estuary The Dee Estuary () is a large estuary by means of which the River Dee flows into Liverpool Bay. The estuary starts near Shotton after a five-mile (8 km) 'canalised' section and the river soon swells to be several miles wide forming the boundary between the Wirral Peninsula in north-west England and Flintshire in north-east Wales. The estuary is unusual in that comparatively little water occupies so large a basin. One theory is that larger rivers such as the Severn and/or Mersey once flowed into the Dee. The current view is that the estuary owes its origin to