I'm not sure a pond would be enough to sustain / attract a population of bats, especially since in most places I've visited in the US, "pond" refers to a very small body of water. A pool is not enough either..
Using the definition they use in Minnesota, what you want is a "lake", and a bigger "lake" than most referred to as such in the Twin Cities. At least a mile long and half that wide ... 320 acres minimum and preferably more.
The house also has to have small openings ... think something a mouse could go through. An inch is plenty. If something like a weasel family animal can get in, they won't move in. It also has to be isolated from climbing rodents / weasels etc; either mounted high on the side of a building or on a tall pole. If animals can run along your roofline and the bathouse on the chimney isn't many feet above that roofline, they won't move in. Oh, and protected from rain. They like to spend the day undisturbed by anything and anyone. Normal human activity, even heavy equipment, won't bother them but they do want to be "cozy".
We put ours either on poles with the bottom entrance 12' above the ground, or on the sides of buildings roughly 2nd story height.