Heavy rainfall: how do you prevent the poop from floating through the city center again?

Last June things went very wrong in the city center of Alkmaar: so much water fell in a short time that the sewerage system in the city center became overloaded. The poop literally floated through the streets. Nienke Bouma is now advising the municipality on how to prevent this. “Last year we saw that the low part in the old town was under water. It came up near the toilets. It was a shower of 90 millimeters in an hour. A really heavy shower. The rainwater flows with the toilet water through a pipe. That is how it has traditionally been arranged, but we are now tackling that.”

lots of green

Where a canal used to run through the city center on the Laat, it is now all stones. The municipality has opted to open up the street for a new ingenious pipe system, which is reflected in a lot of greenery in the shopping street. “This ensures that the water can drain well and that it will feel a lot cooler in the summer,” says Bouma.

In nearby Egmond aan Zee, a lot of water also fell due to a heavy rain shower, which also caused the necessary nuisance. One of the ‘victims’ there is Klazien Hartog, director of the Hoogheemraadschap Hollands Noorderkwartier. She rents out a holiday home in her backyard. “I saw such a huge pack of water from my roof terrace: I thought this is going wrong.”

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Hartog’s holiday home was filled with rainwater from a flooded cistern. “There was so much rain and it became so terribly dark: it almost scared me. I couldn’t get rid of the water in the holiday home. You start mopping. There are five buckets filled and you can’t empty them, because then the toilet would can flood. You really have to make sure you take measures in advance.”

‘I was too late’

Hartog’s holiday home had limited financial damage from the rainwater and her holiday guests were well taken care of, according to the driver. It is striking that the flooding happened to Hartog, because she meets daily for the Water Board about the consequences of climate change. She admits to Koen Bugter: “It’s hilarious too. I bought this house two years ago. I knew from my work that we are dealing with a changing climate and that we have to take measures. I was too late.”

Hartog has already taken measures. “I have flood barriers in front of the door and I make sure that I regularly sweep the sidewalk so that the well does not get clogged. In addition, my patio now has infiltration edges. In other words, not just tiles as before, but I have lifted a number of tiles on the side and there is now gravel and the rainwater can run off there.”