How to know there is a water leak....

When the bill for about a dozen condomium units reflects 4x the area average, there's a fine chance there's a leak.

Glad that's not my bill. The residents there create and are victim of tragedy of the commons. This only happens because a few people end up with leaks that they dont correct, and theres a single bill for the complex. Residents who keep their repairs up get shafted with ever rising condominium fees to send water down the drain.

If you ever consider buying a home bound to a condominium or homeowners association, be sure to check the books and compare to normals for the area.