Im no expert but I do know this if you go with dirt, do it the right way , don’t cut corners , you’ll be better off,
I’ve seen one dam fail my grandad had done, but the guy that did it for him used a tree as part of the back wall, so eventually it rotted and it moved to another location, it’s formed a nice lil pool in the the spot where it ran to, I found it when I was looking for the place he had it put.
But my main point is if you used dirt , maybe some busted up brick, compacted the fire out of it, you’d be better off,
Mix in bentonite with your dirt n maybe busted brick combination, would be more price effective than block n rebar
Matter of fact if your budget allows you could buy a load or three of good dirt known for water retention, combine that with the bentionite, and whatever other materials you choose, I just spitballed broken up brick because it compacts hard and is relatively cheap , always someone willing to give it away from a remodel or demolition
I’m passing on the biggest lesson my grandfather taught me, don’t be cheap on something you want to last, if he had invested more into some of the projects I’m rehabbing they wouldn’t need as much rehab,
Invest In longevity
