Based on what I see, gas riding mowers are still around but for personal use most have either switched to battery or corded electric mowers. So far I haven't heard people complaining about it, and the neighborhood is less smelly and quieter. I am still happy with my corded electric mower I got in 2006, better than a gas one that I would have gotten. Most people in urban area have small enough yard that a 100' cord is fine. If you really really want it you can probably drive to Nevada and bring home a gas mower so it is not that big of a deal.
Drought and water cost is the bigger problem though. I am paying like $6 per CCF and my water bill is often $50 in the winter and $100 in the summer just for water alone. They are that expensive because most of the cost is to fund the earthquake update of the water system that's 100 years old and wouldn't survive another 1 in 100 year earth quake.