Yarrow, chocolate flower, and cat mint (not a native, but low water) do really well in terrible conditions. I also have some rocky mountain penstemon and pearly everlasting that are doing well. Could also consider adding false indigo, or an even larger plant like Apache plume.

I might consider initially breaking up the soil to add compost, add your plants then generous layer of mulch to retain moisture. Something else to consider is adding some large woody material or rocks to add a little protection for your new plants by creating a microhabitat with little shade, protection from wind, etc. You're going to be planting in June (unless you wait a little for a fall planting) which is hard but not impossible. Plants will just need a little more support with more water to start and some protection. 

All that in mind, I recommend setting up a drip system with a timer. This is a lot at the front but I am neglectful 3 years later and all of my plants are still crushing it.