Thames Estuary The new airport would be built on a man-made island in the estuary north of Minster-in-Sheppey There is also some discussion about the need for a Lower Thames Crossing in order to alleviate traffic congestion at Dartford. The Thames Estuary is the focal part of the 21st-century toponym, the "Thames Gateway", designated as one of the principal development areas in Southern England. The appellation Greater Thames Estuary applies to the coast and the low-lying lands bordering the estuary itself. These are characterised by the presence of mudflats, low-lying open beaches and salt marshes, namely the North Kent Marshes and the
Canvey Island been discharged into the river by the means of seven sluices (later known as Commissioners Dykes). The completion of the work saw a considerable number of the Dutch engineers take land as payment for their work, and consequently settle on the island. Approximately one-third of Canvey's streets have names of Dutch origin. The coast of Canvey Island was host to the Chapman Lighthouse as briefly described in Joseph Conrad's novel "Heart of Darkness". It is believed that the peril of the mudflats below such shallow waters off the Canvey Island coast prompted the Romans to devise some form of beacon