[bencyoung]

The Fens in East Anglia in the UK has a lot of interesting pumping tech. The latest can do 100m3/s (https://www.edie.net/st-germans-pumping-station-keeps-fens-f...). If all the pumps failed there would be hundreds of km2 underwater within days or weeks

[Yeul]

In WW2 the Dutch government had to ask the Allies not to bomb any power stations. If left to nature the entire country would disappear in weeks...