MWELO is a statewide water efficiency law for new and renovated landscapes in California. It sets limits on high water use plants and irrigation equipment and incentivizes a holistic approach to landscaping that incorporates alternative water supplies like graywater, harvested rainwater, and recycled water.

Why is MWELO needed?

Traditionally designed landscapes incorporate plants and irrigation that waste water; contribute to polluted water runoff into streams, lakes and the ocean; overspray causing water damage to buildings, fences, streets; and create a lot of plant and trimming green waste.

These landscapes can be beautiful and functional. Research has shown that creating and maintaining landscapes that meet MWELO use 80% less water; require 60% less maintenance; produce 50% less yard waste.

Does this mean the landscapes need to be rocks and cactus?

No, the ordinance encourages the use of a variety of plants including natives, climate-appropriate plants. Limited size lawns and non-adapted plants can be planted.

Who needs to comply?

Any single-family or multi-family residential, public, institutional, or commercial project that requires a permit, plan review or check from the local review agency AND meets one of these size thresholds:

• New construction project with a total landscape area greater than 500 sq. ft.

• Rehabilitation of existing landscape with a total landscape area greater than 2,500 sq. ft.

• See ordinance for details.

Landscape areas include swimming pools, fountains, and other water features.

How does your project comply?

Click here for the Pathway to Compliance.

There are two compliance pathways*:

• Performance Path: new construction projects 500 sq. ft. or larger or rehabilitated landscapes 2,500 sq. ft. or larger.

• Prescriptive Path: projects between 500 sq. ft. and 2,500 sq. ft.

*This also includes pools, spas and water features.

What is the review and approval process?

Prior to construction, submit a signed Landscape Documentation Package that includes:

• Project Information. Download the Water Efficient Landscape Application.

• Landscape Design Plan along with Plant Legend, Specifications, Details and Notes.

• Irrigation Design Plan along with Specifications, Details and Notes.

• Grading Design Plan along with Specifications, Details and Notes.

After the project is approved, construct the landscape according to the approved plans. Once completed submit the Certificate of Completion. Download the Certificate of Completion. It includes:

• Project Information.

• Certificate of Installation.

• Irrigation Audit Report.

Additional MWELO Resources:

Landscape Submittal Requirements

Plant Water Use Factor – WUCOLS plant database https://ucanr.edu/sites/WUCOLS/

Native and Invasive Plants – “Don’t Plant a Pest” https://www.calipc.org/solutions/prevention/landscaping/dpp/

Soil Testing Laboratories – http://cesonoma.ucanr.edu/files/27431.pdf