[quote=lindismith] make sure all the plants are natives so they are climate-appropriate in terms of water use,

If you’re set on your designer, that’s cool, but make sure he uses natives. [/quote]

Using native only plants is fine, but not at all necessary if you want drought tolerant plants. There is a multitude of plants from South Africa, Australia and other Mediterranian climates that are widely available and appropriate for water conservation.