Two nitpicks: - It was completed in 1997. - It automatically closed in 2018, but the algorithm was adjusted to close at a lower water level, specifically to e

Two nitpicks: - It was completed in 1997. - It automatically closed in 2018, but the algorithm was adjusted to close at a lower water level, specifically to enforce a closing under storm conditions. source: https://www.rijkswaterstaat.nl/water/waterbeheer/bescherming-tegen-het-water/waterkeringen/deltawerken/maeslantkering https://www.rijkswaterstaat.nl/water/waterbeheer/bescherming... (that is the Dutch agency responsible for the barrier)