How much of the Netherlands is affected by the problem regulated by the Hoogheemraadschap van Rijnland?
Hoogheemraadschap van Rijnland The Hoogheemraadschap van Rijnland is the oldest water board of the Netherlands, having received its first commission to protect the land from flooding back in 1248 from William II of Holland. It conducts water control activities in the general area known as Rijnland. The Netherlands has 27 Waterboards or "Waterschappen" acting independently from the National government administration to manage the continuing Dutch struggle against water.
Opwijk Opwijk (] ) is a municipality located in the Belgian province of Flemish Brabant. The municipality comprises the towns of Mazenzele and Opwijk proper. On January 1, 2012, Opwijk had a total population of 13,990. The total area is 19.69 km² which gives a population density of 690 inhabitants per km².