I built a number of small ponds (intermittent lentic wetlands) that are
rainfall dependent. I have tried to jump start the invertebrate population
(stumps, water and soil from other ponds), and to some degree amphibians. Tree
frogs came on their own. The ponds almost dried out last year (there was
almost a month long drought) and the frogs were huddling in what was left of
the water. I presume I will lose frogs completely in drought years, but am not
completely sure about this.

What happens to frogs in drought years anyway? They can't all die out, can
they? We had a number (of droughts) in Ohio some years ago, but I never really
thought about this then.