Jenn, I have spent about 10 nights over five years on three different trips. Never saw the water turned off in my old town hotel. Of course I might have been asleep.
I have stayed at the Hotel President. It attempted to be a bit nicer than I needed. I say attempted, but never really suceeded. I have stayed at the hotel Sana. It was very close to perfect for quality and location and great staff and of course price. I would stay there again in a heartbeat. I have stayed at the Hotel Old Town and it was pretty much on par with the Hotel Sana. I suspect the Hotel Sana is quieter but Sarajevo isnt exactly a party town and it gets quiet early.
The Courtyard by Marriott and the Festival are both on the wrong side of the river .... well, not wrong, just not as convenient. But from both you can walk to the old town in 15 or 20 minutes. So the water goes off on one side of the river, but not the other? Interesting. The Hotel Sana might not be techniclly in the old town so maybe its different, but walk across the street and you are in the old town.
AI is often wrong, but: While tap water is generally safe in Sarajevo, temporary water shutoffs can happen for maintenance or issues, but there's no specific, universal "Old Town turns off the water" policy; it's more about localized utility work or potential war-era issues (like 'Sniper Alley' water cuts) resurfacing as maintenance, though major recent shutoffs seem linked to specific infrastructure needs, not a permanent old town feature.