Overview
- Waterschap Noorderzijlvest confirmed a new cyanobacterial (blue‑green algae) bloom concentrated at the popular southwest beach of the Paterswoldsemeer, prompting local complaints about water quality.
- The water board says it routed cleaner water from the Drentse Aa and installed a sand filter last year to cut nutrients and trap debris, but those actions take time to produce a measurable drop in bloom risk.
- Officials point to high temperatures, low rainfall and a long-running northwest wind that pushes stagnating water into the southwest bay as the immediate cause of the local concentration.
- Visitors are advised to consult zwemwater.nl for current swim warnings and to consider alternative sites with good water quality, such as the Hoornseplas.
- Noorderzijlvest emphasizes its aim is to reduce nuisance rather than eradicate cyanobacteria and warns that climate-linked weather patterns make seasonal blooms likely to recur despite technical measures.