Water Efficient Landscape Ordinance

Barbara posts about water use that she observes in Pasadena over on Weeding Wild Suburbia. In the comments is reference to the California State Water Efficient Landscape Ordinance, which is news to me.


All cities in California must adopt it or equivalent by Jan 1, 2010! That's real soon now. However, notice was only given on Oct 8, 2009, which is not a lot of time for cities to react. This mandate is the outcome of legislation passed in 2006 (Water Conservation in Landscaping Act of 2006 (Assembly Bill 1881, Laird)). Apparently the state has been slow to publish the guidelines required to implement it.

From the glossy brochure:
Existing landscapes are also subject to the Model Ordinance.
Water waste is common in landscapes that are poorly designed or not well maintained. Water waste (from runoff , overspray, low head drainage, leaks and excessive amounts of applied irrigation water in landscapes is prohibited by
Section 2, Article X of the California Constitution.

Any landscape installed prior to January 1, 2010, that is at least one acre in size may be subject to irrigation audits, irrigation surveys or water use analysis programs for evaluating irrigation system performance and adherence to the Maximum
Applied Water Allowance as de fined in the 1992 Model Ordinance with an Evapotranspiration Adjustment Factor (ETAF) of 0.8. Local agencies and water purveyors (designated by the local agency) may institute these or other programs to
increase efficiency in existing landscapes.

All new landscapes will be assigned a water budget.
The water budget approach is a provision in the statute that ensures a landscape is allowed sufficient water. There are two water budgets in the Model Ordinance; the Maximum Applied Water Allowance (MAWA) and the Estimated Total Water Use (ETWU).
The MAWA, is the water budget used for compliance and is an annual water allowance based on landscape area, local evapotranspiration and ETAF of 0.7. The ETWU is an annual water use estimation for design purposes and is based on the water needs of the plants actually chosen for a given landscape. The ETWU may not exceed the MAWA.


  1. I still think that making people pay for water at a level commensurate with its value is the best way to get them to conserve. These long complicated rules mostly give me a headache. And you are so right that the new model ordinance is not on most people's radar at the moment.

  2. I agree with Barbara in that all the details give me a headache--ETAF and MAWA and ETWU? Ack. I like the idea of charging the heavy water users, but paying more also doesn't mean much to those who can afford it and plenty to those who aren't so well off and might be using that water to grow some of their own food. San Diego has implemented some of these guidelines, but the PR made it sound like it was only for the duration of the current drought. I don't think the 1/1/10 goal is going to be close to met...

  3. you are so right that the new model ordinance is not on most people's radar at the moment.

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