Model Water Efficient Landscape Ordinance

Santa Rosa Demonstration Garden, Photo by Julie Saare-Edmonds 2015

Low water using plants, mulch, and efficient irrigation save water while making habitat for pollinators. DWR/2015

About 40% of the water Californians use at home is used outdoors. Large water savings can be gained by efficient landscape design, installation, management, and maintenance. This is accomplished by choosing climate adapted plants, improving soil conditions, using, and maintaining high efficiency irrigation equipment and managing the irrigation schedule to fit the plants water needs as they are influenced by local climate. To increase water efficiency and better use a valuable resource, rainwater and stormwater collection and graywater and recycled water can replace or augment potable water use in landscapes.

New development and retrofitted landscape water efficiency standards are governed by the Model Water Efficient Landscape Ordinance (MWELO). The MWELO is also referenced by Title 24, Part 11, Chapters 4 and 5 CalGreen Building Code. All local agencies must adopt, implement, and enforce the MWELO or a local Water Efficient Landscape Ordinance (WELO) that is at least as effective as the MWELO. Usually, local agencies that adopt WELOs create a more stringent ordinance than MWELO.

The purpose of water efficient landscape ordinances is to not only increase water efficiency but to improve environmental conditions in the built environment.  Landscaping should be valued beyond the esthetic because landscapes replace habitat lost to development and provide many other related benefits such as improvements to public health and quality of life, climate change mitigation, energy and materials conservation and increased property values.

Local agencies are required to report on implementation annually by January 31 of each year to DWR’s Water Use Efficiency branch using the WUEdata Portal.

DWR worked with local agencies, water suppliers, landscape industry groups and public interested parties to prepare the current (2015) updated MWELO. To join a list of MWELO interested parties or to join the active Landscape Statewide Advisory Group (LSAG) email with either “MWELO interested party” or “Join LSAG” in the subject line.

Rulemaking Announcement

Regulation Rulemaking on the Model Water Efficient Landscape Ordinance (MWELO)

MWELO Public Notice

recording of the MWELO Public Rulemaking held on January 9, 2024 is available.

New for 2020:

Beginning with 2020 MWELO reports, DWR is using the WUEdata portal for submission of Local Agency annual MWELO Implementation reports. Setting Up Your WUEdata MWELO Reporting Account


WUEdata Portal


2015 - 2019 MWELO Report Assistance and Forms:

To submit 2015-2019 MWELO Reports to DWR, please download and fill the appropriate year’s Report Template below. Send it completed in Excel format to

To view and download previous submissions, please see MWELO Implementation Reports below.

Report Templates for Previous Reporting Years:

MWELO References


DWR is providing technical assistance to local land use agencies and applicants in the form of a Model Water Efficient Landscape Ordinance (MWELO) Guidebook. The MWELO Guidebook will provide background information, explain provisions of the regulation, and give guidance for enforcement to local agencies and applicants. The draft documents posted here are available for public comment and suggestions.

A public meeting was held on January 11, 2021 to introduce the draft MWELO Guidebook to interested parties. See the MWELO Guidebook Presentation for more information. To make comments on the draft MWELO Guidebook, use the MWELO Guidebook Comment Form.

Draft MWELO Guidebook:

The Landscape Statewide Advisory Group (LSAG) was organized in December 2016 to provide a public forum for interested parties in the landscape industry and public agency sector to provide input on landscape water use efficiency topics. The LSAG is open to all interested parties. Currently members of LSAG include Landscape Architects, Landscape Designers, Landscape Contractors, Irrigation Consultants, irrigation equipment manufacturers, soil scientists, city and county staff, water suppliers, State agencies, educators, horticulturists, nursery growers and arborists. To join the LSAG, email In the subject line, write “Join LSAG”.

The meeting materials listed below are available upon request.

  • CII Task Force Summary


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