We were very nearly in for a swim less than an hour after you'd left (well, two did after they fell in ). The rain picked up and we had to climb out of the culvert via one of the open sectons. The current was too strong and the water was too high to proceed through the culvert back to the cars.
I saw the rain mate, a couple of those CSO's started overflowing as I preceded to GTFO, then I got a further soaking back at the car, all in all an evening full of win