A slow day after a long busy period.

Started the morning online shopping a water filtering can. I’ve been losing a lot of hair lately. I read from somewhere that drinking softer water might help. Also many of my friends use filtered water cans.

Then I slowly picked up the research again on my Sloterplas project: trying to understand the water-landscape and its relation to the neighborhood. At Buurtwerkplaats, everyone is telling me the lake has poor water quality. “Not safe for swimming,” they said. Because of the poop bacteria (E. coli) and blue algae.

There are two main causes as said by the municipality of Amsterdam Nieuw-West^*: waste pollution and rising water temperatures.

Bird feeding here is controversial. Food scraps—especially bread—attract birds, and the waste they produce contributes to pollution. Blue algae tend to bloom when water reaches between 20–30 °C. The waterboard is now trying out a TEO system (Thermal Energy from Surface Water) to regulate temperature by cooling the water. Their testing container is just across the canal from Buurtwerkplaats.

But it also brings me back to a question I’ve been circling: what do we mean when we say good water quality?

From the municipality’s perspective, it often means the water is safe for humans to swim in. The humans is the assumed end user. But should that be the only way we evaluate urban water? And the only logic regulating everyone’s behaviour?

At Nieuw-West, people relates to the landscape differently. Take the issue of bird feeding for example, Several people told me that in some households, bread is often fed to birds because it’s easy to go stale at the end of the day, and throwing food away is frowned upon for religious reasons. For others, that bird feeding is a problem, because it’s seen as contributing to the rise of E. coli in the lake. these relations are shaped by culture.

And if we think about the lake, it also comes to the question: why is there a lake in the first place?

I noticed that in the Dutch language the naming of the lake also implies the origin of it. The word ‘plas’ means its manmade, and the word ‘meer’ means it comes from a natural water body. Sloterplas was dug out to source sand to build the surrounding Westelijke Tuinsteden neighbourhood. The lake is artificial.

What does that mean now, and for the future? Do we still need it? Do other species?

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* “Het Sloterstrand is geen officiële zwemplek meer. Het water bij het strand is daarvoor niet schoon genoeg. Er zitten soms teveel poepbacteriën (E. coli) in het water. Ook kan er blauwalg zijn. Zwemmen bij het Sloterstrand en in de rest van de Sloterplas is op eigen risico.” (from Waterkwaliteit Sloterstrand, Amsterdam Municipality, accessed on 23 May 2025) ↩