The Haringvliet Estuary in the western part of the Netherlands was closed off in 1970 by a series of locks as part of the Delta Works for coastal protection. After the closure, the Haringliet became a freshwater body and was used as a source of freshwater for consumption and agriculture. Since 2018, the operating policy of the Haringvliet locks has changed and some locks are opened not only to discharge the river to the sea but also to allow limited inflows from the sea during flood tides to enhance the ecosystem functions of the estuary.