And remember a pond can be drown-proof. You can fill it with stones
to just below water-level, and nearly all pond-life will be perfectly
happy. As the little one gets bigger, you can take stones out and
make room for fish.

Too right. So sad every time we hear of a kiddie being drowned in a garden
pond. Another method is to fix steel grillwork just below the water surface.
A child could stand on it but not fall through., so you could have all the
benefits of a fishpond without the hazard.
DaveK.