I'm wondering how deep I will need to make my pond for some animals and
plants to survive the winter in it. I'm living in a small town the last few
years but was out in the country for decades before that, and I miss the
wildlife, especially turtles, frogs and snakes. The ponds on the farm didn't
have fish and were fairly murky. I want my "in town" pond to be much more
clear, and I may include some small fish.

One problem I've had both in the country and in town is frogs laying eggs in
the swimming pool. I use a Floatron ionizer rather than chlorine or
chemicals, so frog eggs do survive in the pool. Out in the country I would
scoop up the masses of frog eggs from the pool and deposit them in the pond.
Same for any tadpoles I found in buckets or pools of rain water. So one of
the main reasons for making a pond here is to have a handy place to put
tadpoles and eggs.

My efforts with the frogs out in the country paid off well and there were
frogs perched all over the place. I especially liked finding small green
tree frogs. They were numerous enough that their singing drowned out the
barking of neighbors' dogs and let me get to sleep at night. I really need
that here! So I want to cultivate tree frogs. Do they over-winter in the
bottom of a pond like some other frogs do? What about turtles?? (I realize
it will be hard to keep the turtles from wandering off, but I have a plan
for keeping them in the yard.)

Anyway, back to pond depth. I'm in southern Missouri and I've seen winters
with no snow as well as ice several inches deep on the surface of a pond,
even (rarely) a shallow pond frozen almost solid. How dependent on overall
pond size is the likelihood of it freezing solid, or is it all about depth?
If depth is the key, how much do I need? Because I have to do the digging by
hand and I have a bad back (also could hit bedrock not too far down), I want
to make it as shallow as I can get away with and still enable survival of
some animals and plants.

Thanks in advance for all shared wisdom.