Contra Costa County, CA Landscaping Rules: Native Plants (2026)

Contra Costa County has adopted California's MWELO (Cal. Code Regs. tit. 23, Div. 2, Ch. 2.7) as the countywide landscape water standard. The ordinance applies to: (1) new residential landscaping of 500 sq ft or more and (2) non-residential new landscaping of 500 sq ft or more. Projects between 500 and 2,500 sq ft may use a prescriptive compliance path (turf limits, drip irrigation, 3-inch mulch, native/low-water plants) while larger projects must submit a full Landscape Documentation Package with a Maximum Applied Water Allowance calculation. Turf is limited (generally no more than 25% of the landscape area) and prohibited on slopes over 25%. Civil Code 4735 prohibits HOAs from requiring lawn or prohibiting drought-tolerant landscaping, artificial turf approved by the city, or rainwater capture; it also suspends HOA landscape enforcement during state-declared droughts. EBMUD's Lawn Conversion Rebate pays up to $2.00 per sq ft of turf replaced with qualifying low-water landscape (max 1,000 sq ft residential). CCWD offers similar rebates. Greywater systems for laundry-to-landscape and simple shower diversions are allowed without a permit under CPC Chapter 15 if they meet setback and surface-covering rules.