The Rietveld sluice is needed to regulate water levels in the city centre of Delft to prevent flooding. This became evident at the end of the 1990s, when heavy rainfall caused the water levels to rise in the region of Delfland. The normal drainage of the canals from Delft to the river Schie in the region of Delfland was no longer possible. The drainage water levels increased quickly and caused the eastern part of the city to flood. This is situated lower than the western part due to its peat soil. In addition the city centre deals with soil subsidence, which can be seen in the height difference between the picture taken at the beginning of the twentieth century and the picture taken in 2016. Consequently, the water from the canals came up to the facades of the houses.

In 2006 a start was made to tackle flooding in the eastern part of Delft. The Delft canals can be closed off from the storage basin which makes a part of the inner city of Delft a semi-polder. The project consists of a pumping station and eight movable barriers (weirs).

Brain Teasers
What measures can be taken to deal with more heavy rainfall in the future?
What are other results of climate change that are important to take into account in urban environments?

Sources
Dossier (grond)water | Belangenvereniging Binnenstad Noord. (n.d.). https://www.binnenstadnoord.nl/content/dossier-grondwater