I would like to know what the soils are like there. Sandy? Lots of clay?
Where does the water come from?
What do they do each year to maintain those?
Does the soil get richer or poorer?
As permaculture folks, I suspect that we would want to say "not enough
trees", but ....
where might one plant trees so that the tree roots don't compromise a berm
and let all
the water out?