I was going to ask that question - minus the pond part. Our Runners (8 days old) won't be going on a pond, but they will have their own pre-form type pond in their run. I was going on the same advice given for those releasing to large ponds.
We are paying special attention to predation when designing our pen, especially after viewing what appeared to be a good dozen or so turkey vultures flying high in the sky over our street. Scary!!!!