I think I lucked out with my solution. We had two ducks in a large storage tote (about 2 1/2 feet x 18 inches x 16 inches tall) in the basement. Big PITA going up and down the stairs every day to change water, litter, and food. Unfortunately, they were stuck down there longer than I expected since it took so long just to get the chicken coop built, and I didn't have a place for my ducks to stay yet. So I cut 4 pieces of 1/4 inch plywood into 16 inch by 4 foot strips, zip-tied them together to make a "pen", and set it down right on the concrete floor of the basement. Since there's a floor drain about 3 feet from the pen, I didn't have to worry about water overflow. Got rid of their doggie dish and cut out a 6 inch pan from the bottom of a storage tote (maybe about 12 x 18 inches or so), stuck it in the far corner of the pen, and filled it with water. That gave them one corner for playing in the water, one corner under a heat lamp, and two other nice, dry corners out of the heat lamp if they so desired.
Draining and filling was just a matter of dumping the old water down the floor drain and scooping up the little bit of wood shavings. Once I got 'em out, all I had to do was fold up the pen, sweep up the shavings, and run a quick mop over the area. Worked great, but like I said, I lucked out. Wouldn't have worked so well if I didn't have the concrete floor and floor drain.
