to form the Markermeer.

From 1929 till 1967, over half the IJsselmeer was drained, creating 1,979 km2 of polders: Wieringermeerpolder, Noordoostpolder, East and South Flevoland.

In 1975, a dyke was built between Enkhuizen and Lelystad as the northern boundary of the Markerwaard,