Cistus skanburgii

This shrub is drought-tolerant and can live quite happily on little or no water once it's established, though it'll grow more slowly and may not look as lush. This is especially true in coastal California where it is quite adaptive and thrives without additional water once established.

To keep your rockrose looking its best, be sure to water it consistently and deeply while it's getting established, then after a few years give it a good deep soaking every couple of weeks. It will also be happy to have more water, provided the soil drainage is adequate.