Mendocino County Municipal Code Ch. 9A.32 Model Water Efficient Landscaping Requirements—compost and Mulch Use

(A) Property owners or their building or landscape designers, including anyone requiring a building or planning permit, plan check, or landscape design review from the County, who are constructing a new Single-Family, Multi-Family, public, institutional, or Commercial project with a landscape area greater than five hundred (500) square feet, or rehabilitating an existing landscape with a total landscape area greater than two thousand five hundred (2,500) square feet, shall comply with Sections 492.6(a)(3)(B), (C), (D), and (G) of the Model Water Efficient Landscaping Ordinance ("MWELO;" 23 CCR 490 et seq.), including sections related to use of Compost and mulch as delineated in this Section.

(B) The following Compost and mulch use requirements of the MWELO are also requirements of this Chapter. Other requirements of the MWELO can be found in 23 CCR, Division 2, Chapter 2.7.

(C) Property owners or their building or landscape designers that meet the threshold for MWELO compliance outlined in Subsection (A) above shall:

(1) Comply with Sections 492.6(a)(3)(B), (C), (D), and (G) of the MWELO, which requires the submittal of a landscape design plan with a soil preparation, mulch, and amendments section to include the following:

(a) For landscape installations, Compost at a rate of a minimum of four (4) cubic yards per one thousand (1,000) square feet of permeable area shall be incorporated to a depth of six (6) inches into the soil. Soils with greater than six percent (6%) organic matter in the top six (6) inches of soil are exempt from adding Compost and tilling.

(b) For landscape installations, a minimum three (3) inch layer of mulch shall be applied on all exposed soil surfaces or planting areas except in turf areas, creeping or rooting groundcovers, or direct seeding applications where mulch is contraindicated. To provide habitat for beneficial insects and other wildlife up to five percent (5%) of the landscape area may be left without mulch. Designated insect habitat must be included in the landscape design plan as such.

(c) Organic mulch materials made from recycled or post-consumer materials shall take precedence over inorganic materials or virgin forest products unless the recycled post-consumer organic products are not locally available. Organic mulches are not required where prohibited by local fuel modification plan guidelines or other applicable local ordinances.

(2) The MWELO compliance items listed in this Section are not a comprehensive list of MWELO requirements; therefore, property owners or their building or landscape designers that meet the threshold for MWELO compliance outlined in this Section shall consult the full MWELO for all requirements.

(D) If, after the adoption of this Chapter, the California Department of Water Resources, or its successor agency, amends 23 CCR, Division 2, Chapter 2.7, Sections 492.6(a)(3)(B), (C), (D), and (G) of the MWELO September 15, 2015 requirements in a manner that requires the County to incorporate the requirements of an updated MWELO in a local ordinance, and the amended requirements include provisions more stringent than those required in this Chapter, the revised requirements or 23 CCR, Division 2, Chapter 2.7 shall be enforced.

(Ord. No. 4506, § 2, 6-7-2022)