Zuiderzee Works

The Zuiderzee Works (Dutch: Zuiderzeewerken) are a man-made system of dams and dikes, land reclamation and water drainage works, in total the largest hydraulic engineering project undertaken by the Netherlands during the twentieth century. The project involved the damming of the Zuiderzee, a large, shallow inlet of the North Sea, and the reclamation of land in the newly enclosed water using polders. Its main purposes are to improve flood protection and create additional land for agriculture.

The American Society of Civil Engineers declared these works, together with the Delta Works in the South-West of the Netherlands, as among the Seven Wonders of the Modern World.

The "Netherlands" (literally the "lower countries") has low flat topography, with half its land area less than one metre above sea level, and has for centuries been subject to periodic flooding by the sea. The seventeenth century saw early proposals to tame and enclose the Zuiderzee; but the ambitious ideas were impractical given the technology then available.

Plans were developed during the second half of the nineteenth century to protect areas from the force of the open sea and creating new agricultural land. Cornelis Lely (after whom Lelystad is named) was an ardent supporter, an engineer and later government minister. His 1891 plan was the basis for the development of what were to become the Zuiderzee Works. It consisted of a large dam connecting the northern tip of North Holland with the western coast of Friesland and the creation of initially four polders in the northwest, the northeast, southeast (later split in two), and southwest of what would be renamed the IJsselmeer (IJssel-lake). Two major lanes of open water were defined for shipping and drainage. The initial body of water affected by the project was 3,500 square kilometres (1,350 sq mi). Opposition came from fishermen along the Zuiderzee who would lose their livelihood, and from others in coastal areas along the more northerly Wadden Sea. They feared higher water levels as a result of the closure. Other critics doubted whether the project was feasible financially.

...
Wikipedia