Sedums (stonecrops), sempervivums (hens and chicks), ice plant and various creeping thymes require minimal soil depth and appreciate sunny, hot, well-draining soils. All would appreciate a deep watering now and again but can also tolerate a good deal of drought.

I'm not familiar with zone 9, but I know here in my zone 6 garden I have creeping sedum planted in some poor, sandy, quite shallow soil and it does extremely well. It's in a very hot, dry area next to the street. It's also easy to propagate - if you break a stem off, just stick it in the soil and presto! New plant!

:)
Dee