We have a pond smack in the middle of our backyard where my daycare kids play. It was there before I started daycare. We debated closing it and turning it into a sandbox (it's about 4feet by 6feet and about 18inches deep at the deepest).

In the end we opted to keep it (the waterfall and fountain are relaxing and the fish are fun). We fenced it in completely with a fence that is about 4feet tall. The fencing is decorative metal and is close together so there is no way to get through. It is not pretty...even with it being decorative metal. But, it keeps the kids out so we (sort of) still enjoy the pond. The bonus of now having the fence is it keeps the racoons out of the pond so our fish are finally safe!!

I wouldn't consider a pond if it is not fenced in with a tall, secure fence. Children are drawn to water. Our pond is in the back which is fully fenced in...I would certainly not consider installing it anywhere that random kids could access (ie front or side yard not fenced in).

I believe if the pond is deeper than 2 feet then it falls under the pool rules and needs to be fenced and gated in Ontario. But I'm not positive on this...I just know ours is not that deep.