I am sorry for this delayed reply to your gardening question as we are transitioning to a new Q&A system. I hope this reply is not too late to be of help.
I understand the difficulty in getting help regarding your unique landscape situation. I will offer a few thoughts and then suggest you take some photos of the area and visit your County Extension Office to show them for additional ideas and assistance.
It is going to be difficult to plant things where you have no water and to have them grow and look well. Some tough plants to consider are Setcreasea (Purple Heart), dwarf Ruellia, daylily (if the area gets some sun), and dwarf yaupon shrubs.
Thanks for the question. Please stop in again soon!
Q&A Library Searching Tips