Contact your kid's school directly - ring them up or check their website and email for updates. They'll have the latest info on whether they're closing, going remote, or staying open. Most schools post notices pretty quickly when there's disruption like this, so you should get a straight answer without too much hassle.
If the school hasn't put anything out yet, check the local council's website or Thames Water's own updates. They usually have maps showing affected areas and timelines for when things might be sorted. You could also ask other parents in your area - someone's usually got the gossip first anyway.
Don't just assume your school's affected based on the general news. These things vary massively by postcode, and some areas inland won't see much impact while others near the main pipes get hit hard. Once you know what's happening at your kid's place, you can plan whether you need to sort out childcare or set up for remote learning.