They use the same water system as the rest of the LA basin.  Golf courses may look 'purty' but then use a ton chemicals: herbicides, pesticides, & etc. as well as a many acre feet of water per acre to maintain that look.

"Ton" is not a metaphor nor an exaggeration.

US Golf courses are water wasting toxic stews built and maintained for the oblivious.

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre