
I know where the cap is out by the sidewalk for the outside shut off, but I'm hoping to avoid having to resort to having the water dept come out and shut that off

No shut off under the sink, no plumbing under the sink actually except for the drain. The sink is the utility room wash tub and the plumbing comes into the old faucet from above since the water lines are tucked up in the rafters. The hot water can be shut off by the gate valve that comes off the hot water tank before the sink, but the cold water has a Tee that goes off the Tee ahead of the hot water tank and right into the sink. So only way to shut the cold water off is with the main in the access panel.
Just thinking about this stresses me out lol