Last summer, a revolution occurred in Los Angeles landscaping: Across the city, tens of thousands of homeowners tore up their water-thirsty lawns and replaced them with gravel, turf, decomposed granite and a wide range of drought-tolerant plants at a rate never seen before.

The water-saving benefits of this massive landscape overhaul are undisputed — and that’s important in a region that was facing the worst drought in 1,200 years. Still, some experts warned that Angelenos’ zeal to use less water in the backyard would ultimately make the city warmer.