You have what is
called a monolithic pour. This is when the footing and floor are poured
together in one piece -- so the floor IS the footing.
With a monolithic footing and floor, water enters at the Floor-Wall joint.
With this type of construction any type of system requiring jackhammering a channel to put a sub-floor drain in is not an option, because you would be removing 30% of the footing and cracking the remainder, causing serious structural concerns. So it narrows down the solution to an above floor system.
