A dijkgraaf is a dike reeve, the head of a waterschap [water board]. He is responsible for the water management, including flood control, in his district. His function is similar to a mayor of a municipality.
Nowadays, a dijkgraaf is appointed by the King for a period of six years.
Historically, a dijkgraaf was usually somebody who had extensive property in the district for which he managed the water, to ensure he would do his best to keep the land dry. If your ancestor was a dijkgraaf, you may find out more about him in the water board archives.
- “Dijkgraaf (waterschap),” Wikipedia (https://nl.wikipedia.org/wiki/Dijkgraaf_(waterschap) : rev. 29 sep 2016 20:44).