California Model Water Efficient Landscape Ordinance

California
MWELO
Compliance.

The fastest way to validate your California landscape design for MWELO compliance. Search 3,500+ WUCOLS plants, define hydrozones, calculate your water budget, and download permit-ready compliance documents — for any of 366 California cities.

Start Your Project How It Works
MWELO Compliance Tool Since 2006 · 1,200+ Projects Validated
Four steps to compliance

How It Works

01
Start Free

Enter your project address. Your city, ETo and WUCOLS region are detected automatically — no account and no payment to start.

02
Enter Project Data

Choose your project category and scope, enter the landscape area, and define your hydrozones with their irrigation method.

03
Add Plants

Choose plants with the built-in WUCOLS selector. It offers only species rated for your region and applies each plant's correct plant factor automatically.

04
Unlock, Revise & Print

Pay once per project address to see your compliance result. If your design doesn't pass, go back, adjust it and recalculate as often as needed — revisions for the same address are included. Your documents unlock as soon as it passes — then print or download them.

What's included

Everything You Need.
Nothing You Don't.

3,500+
Built-in WUCOLS Plant Selector

Pick from 3,500+ WUCOLS-classified species. The selector lists only the plants rated for your project's region and applies the right water-use category and plant factor automatically — no doubt about whether a plant choice is correct.

366
California Cities

City-specific ETo and WUCOLS region data for 366 cities across 53 counties. If your city isn't listed, select the closest one.

3
Permit-Ready Documents

Print or download the MWELO Water Efficient Landscape Worksheet, plant material table, and a Certificate of Completion PDF pre-filled with your project address — ready to include in your Landscape Documentation Package.

Residential & Commercial

Supports both residential (ETAF ≤ 0.55) and non-residential (ETAF ≤ 0.45) project types.

Pool & Spa Compliance

Include pool, spa, and built water feature areas in your water budget calculation automatically.

Unlimited Revisions

Edit hydrozones, swap plants, and re-validate as many times as you need before closing the project.

1,200+
Projects Validated
Since 2006
20 Years of Experience
58
CA Counties Covered
Fast
Permit-Ready in Minutes

Ready to validate your project?

Your Permit Starts Here.

Stop guessing whether your design complies. MWELO.com runs the numbers and gives you the document your city requires.

Get Started

Not valid for projects in Santa Monica

What you receive

Three Documents.
One Submission.

Once you unlock your result, MWELO.com generates your compliance documents, laid out like the official MWELO forms, ready to include with your permit submission.

01
Water Efficiency
Worksheet

The MWELO Water Efficiency Landscape Worksheet — the primary compliance document showing your ETWU vs MAWA calculation, hydrozone breakdown, and ETAF values.

02
Plant Material
Table

A complete plant material list organized by hydrozone, with WUCOLS species classification, water requirement, and plant factor for each species in your design.

03
Certificate of
Completion

The Certificate of Completion form per MWELO §492.9, as a downloadable PDF pre-filled with your project address. After landscape installation is complete, the property owner or authorized designee completes and submits it to the local agency to verify the project was built in conformance with the approved Landscape Documentation Package.

Three documents · Print to PDF or download · Saved on your device · Ready to include in your Landscape Documentation Package

Talk to the team

20 Years of MWELO.
One Conversation Away.

Behind MWELO.com is a team with more than 20 years of hands-on experience preparing, submitting and getting MWELO compliance documents approved across California. The tool puts that experience at your fingertips — and if your project calls for more, you can talk to the team directly.

Plan checker comments, complex multi-zone projects, local requirements — tell us about your project and we will get back to you.

Talk to the Team → Follow @mwelo_california
Project Review

Have a complex project or an unusual site condition? We can review your hydrozone strategy before you submit.

Plan Checker Response

Got a correction notice from the city? We can help you interpret the comments and revise your submission correctly.

General MWELO Guidance

New to MWELO? We can walk you through the ordinance, hydrozone strategy, and plant selection for your specific project and city.

Common questions

MWELO & WUCOLS — Answered Fast

What is MWELO and when does it apply?
MWELO — the Model Water Efficient Landscape Ordinance — is California's mandatory regulation for water-efficient landscape design. It applies to new construction, ADUs, major renovations, pool installations, and turf conversions where the irrigated landscape area is 500 sq ft or more. A validated MWELO compliance document is required before your building permit can be issued.
What is WUCOLS and how does it connect to MWELO?
WUCOLS — Water Use Classification of Landscape Species — is California's official plant water-use database developed by UC Cooperative Extension. Every plant in your MWELO design must have a WUCOLS water-use classification. Those classifications determine the Plant Factor (PF) used to calculate your design's ETAF and ETWU. MWELO.com includes the full WUCOLS database with over 3,500 species classified by California region.
Who needs to submit a MWELO compliance document?
Any contractor, landscape architect, developer, or homeowner pulling a building permit in California for: new residential or commercial construction, ADU additions, home expansions, pool or spa installations, or major landscape renovations — where the irrigated landscape area is 500 sq ft or more. Many California cities apply lower thresholds. When in doubt, assume MWELO applies.
What does MWELO.com produce?
MWELO.com generates the MWELO Water Efficiency Landscape Worksheet — the actual compliance document your city's plan checker requires. It includes your hydrozone water budget calculations (ETWU vs MAWA), ETAF calculations, ETo reference data for your specific address, and a complete plant material table organized by hydrozone. This is not a summary — it is the permit-ready document.
Does MWELO.com cover my city?
MWELO.com covers 366 California cities across 53 counties, using city-specific ETo and WUCOLS region data. If your city isn't listed, select the closest listed city — its reference ETo and WUCOLS region will be applied to your project. Santa Monica operates under its own local water ordinance and is not supported.
What is the difference between ETWU and MAWA?
ETWU (Estimated Total Water Use) is the calculated annual water demand of your landscape design based on your plant selections, hydrozone areas, and irrigation methods. MAWA (Maximum Applied Water Allowance) is the maximum annual water use your design is allowed under MWELO. Your design passes MWELO compliance when ETWU ≤ MAWA. MWELO.com calculates both automatically using your address's ETo data.