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
Inner Tay Estuary Inner Tay Estuary The Inner Tay Estuary, the inner, western part of the Firth of Tay, stretching from the Tay Railway Bridge in the east to the Queen's Bridge over the River Tay in Perth and the bridge in Bridge of Earn on the River Earn. The estuary is one of the largest in eastern Scotland and is up to 2.5 km wide. The estuary consists primarily of inter-tidal sand and mud flats that extend seaward out to the main channel of the estuary, the majority of which lie on the northern shore. Landward of these are saltmarsh and "Phragmite"s