Water Pines During the Drought

My principal residence is Santa Fe, NM, but I spend large amounts of time in Santa Barbara. Seeing the stone pines dying should come as a serious warning; New Mexico lost an estimated one-third of its native piñon trees due to drought and boring beetles a few years back.

Not only did the losses impact the aesthetics of the iconic landscape, but it also created an increased fire hazard and erosion problems. I have about 200 pinions and paid dearly to water them through the drought, but it was well worth it. I lost one tree in 15 years. Surely the city has access to grey water and tankers to distribute it. What does the city do with its own grey water?