I live in Burbank and we are permitted to water trees by drip irrigation any day, no limit of days, as long as it is between 6pm and 6am. The City's active policy is to keep the trees healthy through the drought.
So, I drip water onto my trees with a hose. Also, in one area I have dripline installed which cuts down on the labor.
Additionally, I run all my washer water into the garden and that's a big boost to the trees in the affected area. I also hand carry my kitchen sink water out to my Chinese magnolia in the front yard, maybe 2+ gallons a day? Every day, though, so I think that is a help.
The other front yard tree is an old established crepe myrtle (maybe 60+ years?) - a drought tolerant tree to begin with, the crepe myrtle seems to be doing fine during the drought. It is on the city-permitted schedule of 15 minutes of water 2 times a week. It has a secret water source though: some years ago we put in a dry well near its root zone. The dry well is connected to a roof down spout, so every rain tops off the dry well which then perks into the soil. The handful of rains we've had this summer have been a boon to the crepe myrtle.
So that's me. But I've noticed many Burbank parkway trees are really suffering, evidenced by significant die-back of upper branches. Their situation is especially dire where the adjacent homeowner has let everything die or replaced all their plants with gravel and a couple of cacti. Pity the poor trees, huh?