voiceofsandiego.org: News... In Arid San Diego, the Grass Isn't Always Greener
This issue keeps coming up. Common sense tells you not to water your lawn because you live in a desert, but the HOA tells you to keep it green.

Nimal Diunugala gives his front yard a five-minute dose of water each night. Not to keep it green. To keep out of trouble. When he doesn't water it and brown patches show up, his homeowners association sends a reminder letter. Its message, in effect: Your grass must be green...In its place, he wants to plant drought-resistant plants, which can include cacti, manzanita and sagebrush. Doing so won't earn him another letter, thanks to a state law that went into effect in January, which prohibits homeowners associations from requiring residents to have lawns. If a homeowner has a lawn, the association can require that it be kept looking lush. But the law prohibits the association from requiring the lawn. Residents now have legal protection to rip out their lawns and plant native vegetation instead.