Contra Costa County, CA Landscaping Rules: Native Plants (2026)
Key Facts
- MWELO threshold
- 500 sq ft new/rehab landscape
- Turf cap
- Generally 25% of landscape area
- HOA rule
- Cannot ban drought-tolerant (Civ Code 4735)
- EBMUD rebate
- Up to $2/sq ft turf replacement
- Greywater
- Laundry-to-landscape permit-exempt
Summary
Native and drought-tolerant landscaping is encouraged in unincorporated Contra Costa County. California's MWELO applies to new or rehabilitated landscapes over 500 square feet, turf is generally capped at 25% of the landscape area, and HOAs cannot ban drought-tolerant plants under Civil Code 4735.
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.'
Full Breakdown
California's Model Water Efficient Landscape Ordinance kicks in when you install or rehab more than 500 square feet of landscape, and it generally caps turf at about 25 percent of the landscaped area. Native plantings help you meet those water budgets. If you live in an HOA, Civil Code 4735 blocks the association from requiring lawn or penalizing drought-tolerant yards. EBMUD customers can claim a rebate of up to $2 per square foot for turf replacement, and a simple laundry-to-landscape greywater system is exempt from permits.
Frequently Asked Questions
Do I need a permit to replace my lawn with drought-tolerant plants?
Can my HOA require a front lawn?
Sources & Official References
- [1]California DWR — Final MWELO Text and Appendices (verbatim 23 CCR §§ 490–495)
- [2]California DWR — Model Water Efficient Landscape Ordinance program page
- [3]Contra Costa County DCD — Staff Report ZT21-00003 (adopting MWELO as Chapter 82-26)
- [4]Contra Costa County DCD — How to Develop Using the Water Efficient Landscape Ordinance
Other rules in Contra Costa County
California rules heatmap·Compare Contra Costa County to another location·View the California landscaping rules overview
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