Examples of 'depoldering' (managed realignment)

Restoration of tidal habitats in areas where enclosure has taken place. Specifically associated with Holland and the Wadden Sea where the word polder has a specific meaning. The examples of this approach to restoring mudflats and saltmarshes include:

• Westerschelde (Holland) where an area of 320ha (Hedwig Polder) was to be restored as compensation for habitat loss due to increased dredging to the Belgium port of Antwerp;
• Beltringharder Koog (Nordfriesland, German Wadden Sea) 853ha c 16% of the polder "reintegrated" with the sea in 1988-9;
• Rantumbecken (Sylt, German Wadden Sea) 570ha "reintegrated" with the sea in 1982;
• Speicherkoog-Nord (Dithmarschen, German Wadden Sea) 532ha c 16.5% of the polder "reintegrated" with the sea 1984;
• L'Aber de Crozon (Brittany) where a relatively recently embanked area (1956) was "re-planned" in 1981.

Comment: The Dutch example was not followed through because of local opposition. The German examples all involved maintenance of the dykes with the tide flowing in and out of the 'depoldered' area through pipes or "sea gates" built into the sea walls (Goeldner 1999).

References

Goeldner, L. 1999. The German Wadden Sea coast: reclamation and environmental protection. Journal of Coastal Conservation, 5/1., 23-30. Abstract...