I'm thinking about my next photobash. I've seen photos of projects turning old, likely nonfunctional swimming pools into walipinis, but conventional wisdom has that there's a big difference between an empty concrete swimming pool and a proper foundation. That the sides will collapse without the support of the pool water, or the water table in the ground will lift the thing like a concrete boat and break it. Just the same, it's not uncommon to see abandoned swimming pools laying empty, looking more or less foundation-shaped. It seems like a very solarpunk thing, to turn an expensive-to-maintain luxury into something practical, a greenhouse that takes less energy to keep it warm.

So my question is: can it be done, especially if the pool is already nonfunctional and you're not worried about returning it to its original use? What steps/precautions should you take to make it last and safe? Reinforce the sides? Cut away part of the bottom? Add drainage around it?

Thanks for any thoughts