California MWELO, 23 CCR § 492.6 — Landscape Design Plan. (b) Plant Selection. (1) Any plant may be selected for the landscape, providing the Estimated Total Water Use in the landscape area does not exceed the Maximum Applied Water Allowance. (2) The architectural guidelines of a common interest development… shall not prohibit or include conditions that have the effect of prohibiting the use of low-water use plants as a group. (3) Each hydrozone shall have plant materials with similar water use. (4) High water use plants, characterized by a plant factor range of 0.7 to 1.0, are prohibited in street medians. (5) Turfgrass is not allowed on slopes greater than 25% where the toe of the slope is adjacent to a non-pervious hardscape and where 25% means one (1) foot of vertical elevation change for every four (4) feet of horizontal length. (6) Methods to achieve water efficiency shall include one or more of the following: (A) protection and preservation of native species and natural vegetation; (B) selection of plants based on local climate suitability, disease, and pest resistance; (C) selection of water-conserving plant, tree, and turfgrass species, especially local native plants; (D) Selection of trees based on applicable local tree ordinances or tree shading guidelines, and size at maturity as appropriate for the planting area; (E) Selection of plants from local and regional landscape program recommended plant lists; and (F) selection of plants from local Fuel Modification Plan Guidelines. (d) Soil Preparation, Mulch, and Amendments. (4) A minimum three-inch (3) layer of mulch shall be applied on all exposed soil surfaces of planting areas except in turfgrass areas, creeping or rooting groundcovers, or direct seeding applications where mulch is contraindicated. Contra Costa County Ordinance Code § 82-26.002(a): 'The water efficient landscape ordinance of Contra Costa County is the Model Water Efficient Landscape Ordinance adopted by the California Department of Water Resources and as set forth in Chapter 2.7 of Division 2, Title 23, of the California Code of Regulations, Sections 490 through 495 and Appendices A through D…' MWELO § 490(c)(5): 'Protecting existing habitat and creating new habitat by choosing local native plants, climate adapted non-natives and avoiding invasive plants.'