No. There is a wide range of plants that will grow successfully in this area that are not California natives. Keep in mind, California is a huge state with many different climate zones, so sometimes a native that is planted out of its adapted area will require more water than another plant. It does help to research which popular landscape plants might become invasive if you live close to wildlands such as the foothills or near open grasslands or desert.
The Water Wise Demonstration Garden at the WCC highlights native plants and non-natives that will do well in our arid climate. Come take a look to get inspiration for your landscape.