I have a garden full of conifers - I'm in Petaluma in Sonoma County, which is not as hot as the interior cities in the County. I have heavy soil and I mulch deeply. Nonetheless, I water with drip irrigation twice a week. Most conifers won't thrive without supplemental water during our dry season. You might go to Regional Park Botanical Garden, in Tilden Park in the East Bay hills, where the collection includes every native CA conifer, and see if some natives might fit the bill. The Friends of the Regional Park Botanical Garden is the supporting organization for that garden and they might also have some ideas for you. Redwoods are a mistake in most CA gardens, either because they need supplemental water (as you discovered) or they grow far too large. Good luck!

Here is a link that might be useful: Regional Parks Botanic Garden

It is usually a guess to just how much water your native soil contains, though an arborist looking at your native trees and how they are thriving can pretty well tell. The road between Calistoga and Santa Rosa was realigned which meant removing a lot of native trees and exposing bare banks of earth. Looking up from our location about a 1000 feet to this scar and all the traffic on the highway was unsightly. We have on our property 3 deodar cedars which produce a quantity of seedlings yearly. Fifteen years ago when the road change was new I dug up a quantity of my seedlings and planted them, in the middle of winter, on the road right of way. With no care they all thrived depending only on seasonal rainfall and soil moisture, They make an excellent screen. Al

Abies cephalonica
Abies pinsapo
Calocedrus decurrens
Cupressus forbesii exceptionally drought tolerant. Thrives here with no supplemental water once established.
Pinus sabiniana
Pinus canariensis only hardy to about 20 degrees.

Maybe an Arizona cypress of some sort, a weeper perhaps? They are quite beautiful.

I was surprised when we went to Tucson I saw many Italian Cypress looking quite good in yards that appeared to be unirrigated. Tough plant!

I love deodars and Arizona Cypress. My neighbor has two Az cypresses that he has NEVER watered in fifteen years. I water them about once every two years in the summer if I am taking care of their chickens and goats when they are out of town. Wonderful trees- the birds nest in them, too. My favorite for our climate is arborvitae- I love chartreuse.
Renee

In case anyone is curious, I thought I'd post what choices I made.

I have planted a variegated incense cedar (Calocedrus decurrens) and have two plain green ones on order.

I have on order one each of the following:

Abies pinsapo glauca (Blue Spanish fir)
Cupressus arizonica glabra (Blue Arizona cypress)
Thuja standishii x plicata 'Green Giant' (western red cedar)

I'll have to water the Thuja for several years at least. It is the riskiest of the selections for a woodland that is intended to eventually get along solely on natural rainfall. However in my area there are a number of mature thuja plicata trees that are not getting any water -- none at all, because there is no lawn near them. A local nurseryman told me that after they are well established they don't need to be watered any more. I do hope he is right. And I hope that 5 years of watering is enough, though someone told me 10 may be more realistic.

Meanwhile I have also been planting oaks, 3 Quercus douglasii and 3 Quercus lobata, along with a number of smaller native trees and shrubs. I wanted to diversify the local pool of oak species because of the SOD problem. My hope is that some will survive.

I'm also hoping for lots of birds. We see decent variety but I want more.

This has been, and continues to be, an immensely satisfying project.

Rosefolly

Thanks for the update. I'm off to look them up!
Renee