A friend of mine had the same problem. It turned out his central water faucet (the one near his water meter, where the water conduit enters his home) had been shut down once and not fully opened again. Probably by someone who had to shut it down in an emergency and didn’t quite know how to turn it fully open again.
Worth spending five minutes on to find out if that is the case.
Yeah, even zombies might ask useful questions.
Polite zombie: “Braaains?” 