Polder
A polder is an area of land that is gained over the water, usually at a level lower than that of the sea, from marshes, estuaries, lakes or coastal areas. The surface to be developed is first surrounded by dikes. The water trapped in this perimeter is then captured by a set of pumps operated in the past by windmills and today by electric pumps. The drainage of the land is facilitated by a network of looms and basins. Even after the dewatering of the polder, the pumps continue to ensure a minimum level of water in the polder. The Netherlands and Belgium are often associated with the polders, since part of their surface has been gained over the sea over the centuries. Such zones also exist in the north of France in the Watergangen or Wateringen region, near Dunkerque, and in the Kamouraska region of Quebec. There are also river polders, natural areas in the flood zone of a river, poldered by a drainage system.