Storing water in ponds has to deal with evaporation, algae growth etc. Also expensive to build. Storing water in tanks means buying and maintaining something a

Storing water in ponds has to deal with evaporation, algae growth etc. Also expensive to build. Storing water in tanks means buying and maintaining something as well. I think the point here is the "low tech, thousands of years old and it works" part. Underground water doesn't evaporate or grow nasty stuff. You do have to have the right terrain I suppose but where you do this sounds awesome. The ground will actually even help with filtering out many nasties.