Hi Mike,
I'm just down the bay from you & have the same concerns about wasting water. Since we're selling our house next spring, I don't want to invest a lot of $ in permanent irrigation, but I have a BIG garden (by Bay Area standards)...
I've hooked several hoses up to a single spigot with a divider attached (don't know the official name). Since I added some plants around the edges of the garden last fall, so they need more frequent water. I built a basin around the plant with compost to contain the water & water with a bubbler attached to the hoses. It's a bit labor intensive, moving the hoses, but when I'm out in the yard anyway, it's not a problem. I simply water a few plants a day, before I leave for work. I water the established beds with a variety of sprinklers, so I don't waste water, again with several hoses, so it doesn't take as long - most of the beds only need once a week water, unless we have a heat wave, like last week. I've dealt with the weed problem by laying cardboard or paper (newspaper or paper bags from fertilizer, compost, etc.) under the mulch - the worms love the cardboard/paper & I feeding the soil, while containing the weeds.
Just my make-shift solution... :-)
Liz