Dutch water boards, waterschappen, are regional governmental bodies managing water barriers, waterways, water levels and water quality (around 26 percent of the area of the Netherlands is at or below sea level).
These water authorities are among the oldest forms of local government in the Netherlands, some of them having been founded in the 13th century.
With a rich history dating back to the Middle Ages, they are the oldest governing bodies and the oldest democratic institutions in the Netherlands.
Dutch waterboards housed on buildings called gemeenlands huis have their own coat of arms.
Below photo is from the Gemeenlandshuis of Leiden.