[Marathon Man]

Originally Posted by golfing eagles

Might be a lot easier than all that. Have a lock on the gate that can be opened remotely from the rec center in charge of that pool and a buzzer. When at the gate, the resident "buzzes" the center, holds his ID up to a camera, and the employee lets him in. One person enters per ID. Make sure residents aren't "polite" enough to hold the gate open for strangers (perhaps with a warning that doing so will result in a suspension of all privileges), while the cameras could detect anyone climbing the fence. Cost would be minimal, and now the rec center employee doesn't have to go out to check IDs except maybe an occasional surprise visit.

And if the Rec Assistant is busy setting up a room?