There've been many times I've sat on my back porch, wishing it'd rain, and watching it rain like crazy right over you. It's pretty hilly out here, which might be a big part of the reason we get so much less rain than you. And when we do get the rain, we're sometimes flooded in.
Just last year my son and daughter and I pulled a neighbor's daughter's car out of about 3 feet of water. She's very lucky because where the car finally had taken on too much water was a spot where I've seen a torrent rip trees right out. And a couple of years ago, before I had my lake largely dammed up, a neighbor girl walked down to our house, having gotten her car flooded out in the creek that my damming of the lake has finally changed to a relatively constant and manageable flow. Got quite a few neighbors who're really glad to see me working on that lake. Them getting rained in used to be a 2-3 times per year event, but hasn't happened once since getting the dam to the stage it's at now. It'll likely still happen occasionally, but even less frequently once I get it raised another 8 feet, which should give me something like 10 acres under water.
Hard to calculate such things, but based on estimates while watching the biggest storm I've ever seen hit out here years ago (a huge flow of mean water through the dam breach that'd existed for about 10 years), I think that the additional 8 feet plus constantly draining it down at a pretty decent clip to make electricity *should* give me enough capacity to hold back the worst rains finally. Almost lost the dam once last year when I hadn't been draining it down fast enough (was constantly draining through a 2-inch pipe) and water started going over it. Cutting the pipe back to the 4-inch section helped a lot. I've got some pretty intricate plans for increasing the outflow as water level increases, but I don't have any of that work done yet.