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
Estuary of Bilbao reached high levels of contamination because of the industrial activities during the past century. see page:http://bilbaoenconstruccion.com/2010/07/06/bilbao-recupera-su-alma-plan-integral-de-saneamiento-de-la-ria/ Estuary of Bilbao The Estuary of Bilbao (Spanish: "Ría de Bilbao" / Basque: "Bilboko Itsasadarra") lies at the common mouth of the rivers Nervion, Ibaizabal and Cadagua, that drain most of Biscay and part of Alava in the Basque Country, Spain. In this instance, the Spanish word estuario is used to describe what in English would normally be called part estuary, part tidal river. The estuary becomes a tidal river which extends into the city of Bilbao, starting from the Bilbao Abra bay. It