in most places I've seen, there's no sewer fee, there's only a water fee
they want the water back, so it can be processed and put back into the system
Oh, you live somewhere that's essentially a desert. Where water is plentiful, water and sewer are usually separate - sprinkler system goes on a separate water meter to avoid sewer charges (which for me are higher than the water charges).
If you're looking for low maintenance alternatives to a yard, fwiw, and you're in USDA zone 7 or higher, Asiatic jasmine will grow under almost any lighting conditions (from full sun to directly under a live oak), and only needs to be cut once a year. Very tolerant of steep slopes, too.
I'm not in love with the fossil fuel industry, but for all their problems it's also dangerous to assume that installing wind farms on every decent hillside won't have climatic effects. Go nuclear or give up.