Here are a couple of old pictures of mine. In the first shot the river is only about four or five inches below the top of the wall on the quayside. I was stood in a couple of inches of water at the time.
IMG_6273 by Alan Evans on Flickr
This was shot a couple of hours later, from the far side of the road that runs along the quay. The point that I took the previous shot from is under a couple of feet of water at this point. Fortunately the water stopped about an inch from overtopping the quayside wall. All the water across the quay and the road came back up the rainwater runoffs, that just pass the water out in to the river. At the time I lived about 20 yards from where the water rose to, but fortunately for me there was another block of flats between me and the river, they were lucky too as since the wall wasn't overtopped the water didn't even get that far. At least it got me out photographing the ships in the port.
IMG_6303 by Alan Evans on Flickr
These are great, Al, and thanks for the back-story.