What is MWELO?
In California, about half of the urban water is used for landscape irrigation. Substantial water savings can be gained by proper landscape design, installation, and maintenance. To improve water savings in this sector, Governor Brown’s Drought Executive Order of April 1, 2015 (EO B-29-15) directed the Department of Water Resources to update the State’s Model Water Efficient Landscape Ordinance (MWELO) through expedited regulation. The California Water Commission approved the revised MWELO on July 15, 2015. MWELO promotes efficient landscapes in new developments and retrofitted landscapes.
Which Projects are Subject to MWELO?
New development projects that include landscape areas of 500 sq. ft. or more are subject to MWELO. This applies to residential, commercial, industrial and institutional projects that require a permit, plan check or design review. The previous landscape size threshold for new development projects ranged from 2500 sq. ft. to 5000 sq. ft.
The size threshold for existing landscapes that are being rehabilitated has not changed, remaining at 2500 sq. ft. Only rehabilitated landscapes that are associated with a building or landscape permit, plan check, or design review are subject to MWELO.
What are the Significant Revisions?
More Efficient Irrigation Systems
• Dedicated landscape water meters or submeters are required for residential landscapes over 5000 sq. ft. and non-residential landscapes over 1000 sq. ft.
• Irrigation systems are required to have pressure regulators and master shut-off valves.
• All irrigation emission devices must meet the national standard stated in the Ordinance to ensure that only high efficiency sprinklers are installed.
• Flow sensors that detect and report high flow conditions due to broken pipes and/or popped sprinkler heads are required for landscape areas greater than 5000 sq. ft.
• The minimum width of areas that can be overhead irrigated was changed from 8 feet to 10 feet; areas less than 10 feet wide must be irrigated with subsurface drip or other technology that produces no over spray or runoff.
Incentives for Graywater Usage
Landscapes under 2500 sq. ft. that are irrigated entirely with graywater or captured rainwater are subject only to the irrigation system requirements of Appendix D, Prescriptive Compliance Option.
Landscape Documentation Package Submittal Requirements:
Approval of a complete landscape package is required prior to construction of any landscape. Submittal requirements are summarized below. MPWMD’s Landscape Documentation Package and Appendix D (Prescriptive Compliance Option) can be found here.
- Water Efficient Landscape Worksheet
- Soil Management Report
- Landscape Design Plan
- Irrigation Design Plan
- Prescriptive Compliance Option (Schedule D) is available to specific projects
- Project with an aggregate landscape area of 2,500 square feet or less
- Projects using graywater or rainwater captured on site: Any lot or parcel within the project that has less than 2,500 sq. ft. of landscape and meets the lot or parcel’s landscape water requirement (Estimated Total Water Use) entirely with treated or untreated graywater or through stored rainwater captured on site is subject only to Appendix D section (5) Certificate of Completion Package: At the completion of the project, a Certificate of Completion Package is required.
Certificate of Completion Package Submittal Requirements:
For new construction and rehabilitate landscape projects installed after December 1, 2015, the following documents must be provided to the owner and to MPWMD upon completion of the landscape project:
- Certificate of Completion. This form is completed and signed by property owner.
- Certificate of Installation. This form is completed and signed by the signer of the landscape design plan, the irrigation design plan, or a licensed landscape contractor. Certification shall be based on periodic observation of the installation.
- Irrigation audit report;
- Controller parameters/settings;
- Landscape irrigation audit report;
- Soil analysis report and documentation verifying implementation of recommendations from soil analysis (if not using the Prescriptive Compliance Option).
- ETo Zones Map
- Model Water Efficiency Landscape Ordinance
- WUCOLS III – Water Use Classification of Landscape Species published by the University of California Cooperative Extension and the Department of Water Resources
- Invasive “pest” plants (California Invasive Plant Council’s “Don’t Plant a Pest”)
- California Irrigation Management Information System (CIMIS). Local ETo zones are 1, 2, 3, and 6. Monterey Peninsula CIMIS stations are located in Carmel (Station 210), Laguna Seca (Station 229), and Pacific Grove (Station 193).