I only have ducks (1 drake and 1 duck) and chickens (all hens) together. They get along well, except the drake acts like he's in charge and also likes to "assert his dominance" on a few of the hens that he was raised with. The ducks have a small stock tank that they use as a pond and waterer. It gets pretty dirty quickly, so I have a pump in it that circulates the water but not as effectively as hoped. The chickens perch up on the edge of the tank and drink from the tank. When the drake chases the few hens around the yard and into the coop, the hens jump up on their perches to get away from him.
I'm raising a few more ducks from eggs in the hopes that he will have more proper targets to go after and leave the hens alone. The trade-off will be more of a mess caused by more ducks, but they have a half-acre they can free-range in for the entire day, which helps to thin out the mess.