Food Garden over flood area in concrete backyard
I am renting a home in center city Philadelphia and have a small walled concrete slab for a backyard. The slab is very old and has sunken such that when it rains all the water/other junk bypasses the in-ground drain and pools in the back corner. It then sits there for a day or two while it evaporates.
I am thinking about building a small food garden over that spot. Is this a good idea? Should I allow the rainwater to pool under the garden or should I try and seal the bottom so no water passes underneath?
I am worried that the rainwater may cause mold or other damage if it sits.
Fixing the concrete is not an option because I am renting and the landlord already said no.
I am open to all suggestions. Thanks!