Ah, yes, drainage! Thanks, for the tips. Your set-up sounds excellent, Pokey, and I've added gutters, downspouts and drains to my wish list on the covered run. DH and son included those in the design of the greenhouse they built for me several years ago as a Mother's Day present, but I don't think any of us considered doing that for the chicken run. I had dug a halfhearted ditch around the perimeter but, clearly, not adequate to handle anything like the downpour we've had this week.
I'll tell you guys this, in spite of my griping, I am grateful this learning experience came in May and not November when the chances of getting a dry day for reconstruction are somewhere between slim and fat. Actually, now that I'm all dried out and had time to think about it, I'm sort of looking forward to building the coop I really wanted to build in the first place and, hopefully, make a better job of it because I've learned a few things.
BTW, the rain slacked off today so I turned the girls out. They pretty much beat feet for the area under the coop and are now all piled into about 4 square feet right in the center where it remained semi-dry. They're all having a nice dirt bath. Gotta love chickens and their untroubled attitude