cut (one's) water off
1. Literally, to turn off the flow of water, typically to one's place of residence. If you don't pay your bill, the water company will cut your water off.
2. To thwart or stifle one. We need to cut this guy's water off before he totally undermines what we're trying to accomplish here.
cut someone's water off
Fig. to squelch someone; to thwart someone. (Fixed order.) Well, I guess that cuts your water off! That sure cuts off my water!