A couple of guidelines I have found helpful are that ducks must have water if there is food available so they don't choke (it can happen), and they can go without water for 8 hours or so with no problems unless it is really warm.
I avoided the mess issue by having, attached to their house, a hardware cloth covered veranda with a sand and sawdust floor where they have water all the time. I take the food away overnight to reduce predator attraction.
This winter, because the ducks aren't doing real well with below freezing, they are in the walk-out basement overnight. I have water for them in that area, but it sits in the bottom half of a large plastic dog crate - it catches all the water. I put sawdust pellets in the bottom of the crate to absorb splash. I empty it every few days. But this is just temporary, till we figure out a better long term winter solution. It's not bad, though. No ugly smell, no water on the floor (I put sawdust down around the crate just in case).