Which State Law Regulates Landscape Irrigation In California?

Do you know which state law regulates landscape irrigation in California?

Do you know which state law regulates landscape irrigation in California? AB 1881 created the new Model Water Efficient Landscape Ordinance which changed the way landscape architects design irrigation systems and prepare for the California Supplemental Exam for Landscape Architects.

Like most other parts if our professional life in California, landscape irrigation is regulated by state law. Since water is a scare resource in a dry state, water conservation is a reasonable response to reduce water demand and stretch this precious resource.

Assembly Bill 1881

In 2006, the California State Assembly passed AB 1881 which required all local agencies to develop water conservation policies by 2010. To create a minimum standard that could serve as a guide for local agencies, the California Department of Water Resources created the Model Water Efficient Landscape Ordinance. The new Model Ordinance updated the requirements of AB 325 which was passed in 1990.

What AB 1881 Does For Landscapes

AB 1881 updated the language and technology requirements of AB 325:

  • Drip irrigation equipment was included as “appropriate technology” in the bill and ordinance
  • Requires swing joints to reduce wasted irrigation water caused by broken spray heads
  • Updates irrigation controller requirements to match improvements in technology
  • Prohibits spray irrigation within 2 feet of impervious surfaces
  • Prohibits spray irrigation on area less than 8 feet wide

Swing Joint for the California Supplemental Exam for Landscape Architects

What AB 1881 Doesn’t Do

AB 1881 does not ban the use of any plant or any plant type in the landscape
Turf grass usage is curbed (but not eliminated) under AB 1881
Does not require landscapes to be retrofitted unless a construction permit is required for new construction or remodeling

Who Is Targeted?

AB 1881 is primarily targeted at commercial development and builder-installed residential landscapes

While residential landscapes and homeowners are not the primary target of the law, homeowners will have to comply with the ordinance if new construction has 5,000 square feet of landscaping when they renovate.

Does AB 1881 Set Statewide Standards?

Yes…and no.

The Model Water Efficient Landscape Ordinance sets the minimum standard for water conservation in the state. But, local agencies can establish more stringent requirements. For example, the city of Santa Monica has a much stricter water conservation ordinance. Check with your local city or county agency to determine the correct standard before designing your project.

The Future

As of 2010, AB 1881 became law and all agencies will either adopt the ordinance in its entirety or develop their own more stringent version.


  • Not much change from AB 325
  • Updated language allows drip irrigation and improved controllers
  • Will likely reduce water usage


  • Hard to enforce water usage after the initial permit process
  • Increased compliance cost for clients

Read the Model Water Efficient Landscape Ordinance here.


Pass the California Supplemental Exam (CSE) for Landscape Architects e-book study guideIf you are looking for a study guide to help you prepare to pass the CSE the first time, check out Pass the California Supplemental Exam for Landscape Architects study guide e-book.


John is a landscape architect who is currently preparing to take the California Supplemental Exam to become licensed in California. He is currently a licensed professional landscape architect in Georgia and Florida. John graduated from California State University, Pomona with a BSLA degree in landscape architecture in 1997 and has extensive practice experience in residential and commercial landscape design.

Posted in Regulatory Agencies, State Agencies, Water Tagged with: , , , , , , , ,

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