Have you considered changing the sprinkler heads in that area slo they spray farther.

Anything you plant will need regular watering until it is established.

Do aloe and agave fall into the cactus family in your book? Several varieties of aloe would make a nice display when they bloom, and many are frost tolerant.

Here is a link that might be useful: Aloe family link

Some of the daisies like it very dry: Viguiera stenoloba which isskeletonleaf goldeneye daisy, cut leaf daisy, or Missouri primrose is another choice. Of course, you'll have to water with a hose until established.

lantana, vinca, liriope, zinnias, canna lillies .... mine all fend for themselves and look none the worse. Of course I don't live in the desert, but I have seen all of these plants go 2+ weeks without rain.