Unfortunately the point of a hedge is to stay green and full. If you want green leaves and dense structure you need water. Depending on how high you want to go I have seen elephant bush used it takes very little water but grows slow and uneven.

Sometimes I suggest to put water to what is most important and if a hedge is really important to you then you might want to consider water for it. Podocarpus, eugenia, grewia are all decent hedge plants..but need water.

We use privet bushes as a hedge row here. Once established, they need water only once a week in the hottest part of the summer. They do like full sun and I'm not sure if there are multiple varieties but ours are 10' high and screen well.

Escallonia does well here in SoCal

If you're still looking, I suggest highcountrygardens.com. Everything they sell is drought resistant and eco friendly. They have a ton of great information on their site, and even if you don't ultimately buy your plants from them, it may help you narrow down the best options for a hedge in your area. I'm getting two of their "pre-planned gardens" for my yard, in which I'm doing xeriscaping, which is landscaping with all drought resistant plants. I may get some succulents from them as well.

What are the dimensions of your space? How tall and wide can you go?

Whatever you pick, it will need water until it is established.

Consider hopbush (Dodonea viscosa) for its deep green color and upright growth habit.