Have 15 acres on a mountain in AL; there is granite under a lot of it.

I want to put a natural pond in and feed it from runoff of two metal roofs on the house and barn/shop. Is this possible? Is it safe to have animals like dogs, chickens, and ducks to have access to the pond? Does there have to be special filtration for this application? How big would it need to be to be able to sustain itself? The house and the shop will each be about 2000sft.
Thanks

1. Find your local evaporation rate.  There are websites showing how to measure this at home.

2. Total roof square footage x annual average rainfall x .623  (gallons) x .70 (rough efficiency estimate) = total water input per year

3. Should be able to compare these. Would probably multiply the evaporation rate by the square surface area of the pond when full?  Or the cubic capacity of the pond?  I'm not sure from this point.