High Quality Content by WIKIPEDIA articles! The Zuiderzee Works (Dutch: Zuiderzeewerken) are a manmade system of dams, land reclamation and water drainage works, 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.