Land Connections  

This mailer has been provided as an avenue to disperse information pertinent to public agencies and the landscape architecture profession in hopes of fostering greater understanding and collaboration. Topics address issues that affect the built environment within which we live.


The California Water Efficient Landscape Ordinance Updates

"Water conservation is a key link between balancing current and future water needs." Southwest Florida Water Management District

The December 2008 issue discussed the California Water Efficient Landscape Ordinance; since that time there have been several public comment periods and many revisions to the ordinance. As implementation for this ordinance draws closer (January 2010), there is an ever increasing sense of urgency to be as prepared as possible. This should weigh heavily on local agencies as there is potentially a significant amount of review and revision that will need to take place. This edition of LAND Connections will address a few of the many changes that many local agencies will be required to fold into their current standards and ordinances. Changes may be as simple as updating a standard detail or street section in some cases and may spark a total re-write of agency standards and ordinances in others. The following requirements are of particular interest:

Landscape Document Package -
A landscape document package will be required for new or rehabilitated construction projects. This package will at a minimum be required to include the following:

  • Project Information (Contact information, landscape area, water supply type, etc.)
  • Water Efficient Landscape Worksheet
  • Soil Management Report
  • Landscape Design Plan
  • Irrigation Design Plan
  • Grading Design Plan.

Water Efficient Landscape Worksheet -
This worksheet will be required as part of the landscape document package to demonstrate adherence to the ordinance and its purpose in conserving water. The worksheet is comprised of a hydrozone information table for all hydrozones, a "Maximum Applied Water Allowance" (MAWA) calculation, and an Estimated Total Water Use" (ETWU) calculation. These water budget calculations are shown below for your reference. Adherence to the ordinance means that the ETWU calculation must not exceed the MAWA calculation.

MAWA=(ETo)(0.62)[(0.7 x LA)+(0.3 x SLA)

ETWU=(ETo)(0.62)[((PF x HA) / IE) + (SLA)]

Soil Management Report -
A soils analysis will now be required with a landscape document package submittal and should include information such as soil texture, infiltration rates, pH levels, soluble salts, sodium, organic matter content, and recommendations. The designer will use this information to prepare an appropriate planting and irrigation design.

Landscape Design Plan -
Landscape design plan requirements are focused primarily on recreational amenities and the selection of plant species to assist in the conservation of water. Protection and preservation of native plant species and selection of water conserving plants is highly encouraged. Significant changes to this section include:

  • Plant materials with similar water uses must have their own dedicated hydrozones.
  • Turf grasses will not be allowed on slopes greater than 4:1 (25%) which are near hardscape surfaces.
  • All water features will be required to have re-circulating water systems. (ponds, lakes, waterfalls,fountains, streams, spas, swimming pools, etc.)

Irrigation Design Plan / Scheduling -
This section is where the bulk of changes are being made.
Significant changes to this section include:

  • Weather based or soil moisture driven irrigation controllers will be required.
  • Sensors (rain, freeze, wind, etc.) will be required based on local weather conditions.
  • Manual shut-off valves near the water supply will be required.
  • Check valves or anti-drain valves will be required.
  • Spray irrigation will be prohibited in landscape areas less than 8' wide.
  • Spray irrigation will be prohibited within 2' of hardscape unless sloped to drain towards landscape areas.
  • Slopes greater than 4:1 (25%) shall be irrigated with a precipitation rate less than .75"/hr.
  • Overhead irrigation shall be confined to a watering window of 8:00 p.m. to 10:00 a.m. unless local water scheduling is more stringent.
  • Irrigation schedules submitted for approval must include the following information: irrigation intervals, irrigation run times, number of cycle starts, monthly applications of water,application rates, root depth setting, plant type setting, soil type, slope factor setting, shade factor setting and irrigation uniformity efficiency setting.
  • A routine maintenance schedule must also be submitted and approved.
  • An irrigation audit report must be submitted with the project certificate of completion.
  • Irrigation designs must meet or exceed an irrigation efficiency of 71%.

Grading Design Plan -
A grading plan must be submitted with the landscape document package to ensure that the project is designed to minimize impacts caused and related to runoff. Required information includes finish elevations, high points, drainage patterns, pad elevations and stormwater retention improvements.

Irrigation Programs (Audits / Public education / Prevention) -
In addition to project application requirements there are public program requirements that must also be met. Local agencies will be required to administer programs that confirm project compliance with irrigation requirements and proper continued maintenance. Agencies will also be required to provide new home owners with educational material related to water efficiency in the landscape. Local agencies will also be responsible for establishing penalties for violations related to inefficient irrigation systems and water waste.

With less than 4 months remaining until this ordinance becomes active, there is plenty of work to be done. If you could use some assistance wading though the ordinance requirements please contact O'Dell Engineering's landscape architecture department to see how they might be able to assist.

O'Dell Engineering

The next time you need a Landscape Architect on your project, consider O'Dell Engineering's Landscape Architecture Department.

Services include:

  • Park and Playground Design
  • Recreational Facility Design
  • Site Planning
  • Streetscape Design
  • Urban Design
  • Commercial Design
  • 3-D Visualizations
  • Graphic Design
  • Arborist Consulting






  • Trees & the Urban Environment Part I
  • Trees & the Urban Environment Part II
  • Trees & the Urban Environment Part III
  • Universal / Inclusive Design - Part I-Playgrounds
Author: Chad Kennedy, Landscape Architect

This informational article provided by O'Dell Engineering - 1165 Scenic Drive, Suite A, Modesto CA 95350