I'm in So. Cal. as well. With our environment it's just not possible to hunt without carrying a fairly good amount of water. Wether I'm hunting here or in Arizona I use a hydration pack with 2.5-3 liters of water. If I'm not going far I use a Camelbak that I normally use when mt. biking. If I'll be out all day I have a larger pack that also takes the water bladder.
I don't see why a plains style quiver wouldn't work. I usually use a leather tube I made that can be lashed to the side of my pack and holds 4-6 arrows. Coupled with two broadheads in a bow quiver I'm pretty well set.
Guy