No-one mentioned the shower arrangements at Mosedale Cottage. I got there at 4.30pm on the Friday, and left with everyone else after 10am on the Saturday. I discovered that by walking out of the front door, it was possible to enjoy a cool shower any time of the day or night. I never discovered how to turn the water off, so it might still be running!
As for a water supply... the beck alongside the cottage was in spate and was rather brown and murky. On the other hand, water falling on the cottage roof, collected by the gutter and coming down the drainpipes, was perfectly clear. I didn't have any worries about how clean the roof might have been, since it must have been thoroughly washed-down this year!