As we don’t want another flood, the Boy and I spent more than an hour getting at the offending floor drain today. Naturally, it is under a stud (supporting an electrical outlet), and so, it wasn’t a simple matter to get at it.
The hole is simply straight through the concrete, 3 1/2 inches in diameter. Rona and Home Depot were no help whatsoever in plugging it up. I’m hoping a real plumbing supply may be able to propose something on Monday.
Pembroke:87 
If it helps, had a very similar issue in Upstate NY. It’s a floor drain that goes in to the main sewer pipe that goes from the main stack to the street. If there’s heavy rain, my basement would flood — and it’s not water… yuck. Tried to fix it myself, and couldn’t figure it out. Called my favorite plumber, and $35 in labor and $5 in parts fixed it with a screw-in cap.
Bottom line: sometimes, the best help is from a pro…
Pretty happy ours was just rain water!
Of course it was under a stud. Adding insult to injury. I hope you recover from this soon.
Cheers Hunter. The rebuild is certainly taking longer than we’d hoped!