To me, the very idea that someone could steal water in such amounts is mindboogling.

Here, we have metering for each connection, and, on top of this, metering at key nodes all over the grid. Not to catch someone watering their lawn unmetered, but to watch for leaks. Water is considered important, so the utilities have strict monitoring requirements. If the measurements don’t add up in a segment, the utilities immediately start to investigate, as any leak that lets water out could also let dirt in - an absolute no-go here.

They would have caught the culprits after the first few cubic meters.