Hoogheemraadschap van Rijnland

The Hoogheemraadschap van Rijnland is the oldest water authority in the Netherlands, having received commission to coordinate protection of the land from flooding in 1248 from Count William II of Holland and Zeeland.

The Netherlands has 21 Waterboards or Waterschappen acting independently from administrative governing bodies to manage Dutch water control activities along with the fine-mazed polder systems.

[1] The first steps towards a governing organisation of water management were taken in the 12th century when the Oude Rijn river silted shut at the North Sea mouth near Katwijk.

To deal with this problem, the local nobility of Leiden decided to build a dam at Zwadenburg, now Zwammerdam, close to the border with the German Kingdom.

Meanwhile, around Leiden digging work had started to increase the draining efficiency of the small rivers called the "Zyl" and "Does", which would carry the overflow towards the Haarlem Lake and the Kagerplassen.

By 1255, according to the oldest dated document in the Rijnland archives, there was a collaborating group of officials called heemraden who oversaw the dikes along the IJ river at Amsterdam and in the Rhine at Zwammerdam.

When the Hof van Holland decided in favor of repairs, Haarlem asked to have the dam (and sluices with their tolls) moved closer to the city.

To manage the finances of building and maintaining the dam and all its sluices, it was decided to split the costs (and toll income) among the water boards downstream.