Artificial grass, river rock, gravel.....no 'plant' will grow with no water. Hello?

In Arizona you will need to water the plants.

Those plants that can survive with no supplemental water aren't very decorative, and aren't the right size to plant between stepping stones.

No water usage, nothing, but sometimes occasional overspray from sprinklers or very little watering would suffice.

Look into Sedum (various types), Ice Plant, Creeping Thyme and Alyssum