We have a big black plastic tub (one for livestock), and put a drain in it made from pvc piping and it drains out into the ground. Its set up on a block made of leftover stuff from our deck. Set up a shower system, which works great cause before we were just using the hose. And my dad made a platform that can be taken in and out, so the bulldogs are easier to bathe with that, and if BB is in it I take the platform out. I have a picture of it, before we enclosed the porch into a dog room, so it's just the basic set up of it on cinder blocks.