I have 9 ducks and well over 70 hens and they all exist wonderfully together. I also have a raised pond, and several little kiddie pools in the yard for the ducks and water stations all over the yard for the chickens. I have lost a few pullets in the kiddie pool (less than 2 months old), and several times have found a pullet swimming in the pond, (not by choice), but for the most part, I have had this set up for the past 6 yrs. and the incident rate has been really low. Even though I have water stations everywhere, the chickens do enjoy getting their water source from the pools and pond. I have since staged rocks inside and outside of the pools and pond to make it easier for the ducks to get in and out and hopefully a preventive measure to keep another pullet from drowning. I too, keep the water levels high so their are no accidents with the pullets falling into the water while trying to drink. Never experienced a full grown hen drowning though. I hope you do get your ducks and enjoy the heck out of them, they are wonderful.