Regulatory Agency Series: Part 8
Irrigation Controllers for CALGreen and the Model Water Efficient Landscape Ordinance
Is Your Irrigation Controller Illegal?
Do you know what seperates a legal irrigation controller from an illegal one?
Are you inadvertantly breaking the law when you specify a certain controller?
In this article, we will examine the requirements set forth in California regulations for irrigation controllers. You need to know what features are required for irrigation controllers in order to pass the California Supplemental Exam for landscape architects.
Irrigation Controller Regulations
There are a few regulations and codes that specify what kind of features irrigation controllers need to comply with California standards.
- Model Water Efficient Landscape Ordinance
CALGreen Irrigation Controller Requirements
CALGreen is the new green building code that governs new construction and renovation in the State of California. CALGreen became active in 2010 and is still in its infancy. Expect changes to the CALGreen building code in the future.
In new nonresidential construction with between 1,000 and 2,500 square feet of landscaped area, property owners must install irrigation controllers and sensors which include the following criteria, and meet the manufacturer’s recommendations.
5.304.3.1 Irrigation controllers. Automatic irrigation system controllers installed at the time of final inspection shall comply with the following:
- Controllers shall be weather- or soil moisture-based controllers that automatically adjust irrigation in response to changes in plants’ needs as weather conditions change.
- Weather-based controllers without integral rain sensors or communication systems that account for local rainfall shall have a separate wired or wireless rain sensor which connects or communicates with the controller(s). Soil moisture-based controllers are not required to have rain sensor input.
Fortunately, these requirements are closely aligned with the California Model Water Efficient Landscape Ordinance
California Model Water Efficient Landscape Ordinance Irrigation Controller Requirements
Residential and commercial new construction and renovation that falls under the Model Water Efficient Landscape Ordinance require an automatic irrigation controller.
In the ordinance, irrigation controllers are defined as:
An “automatic irrigation controller” means an automatic timing device used to remotely control valves that operate an irrigation system. Automatic irrigation controllers schedule irrigation events using either evapotranspiration (weather-based) or soil moisture data.
Irrigation controllers must meet the following criteria:
- Automatic irrigation controllers must utilize either evapotranspiration or soil moisture sensor data for irrigation scheduling in all irrigation systems.
- Irrigation scheduling shall be regulated by automatic irrigation controller. Automatic irrigation controllers utilizing either evapotranspiration or soil moisture sensor data shall be required for irrigation scheduling in all irrigation systems.
- Automatic irrigation controllers are required and shall use current reference evapotranspiration data, such as from the California Irrigation Management Information System (CIMIS), other equivalent data, or soil moisture sensor data.
- Sensors (rain, freeze, wind, etc.), either integral or auxiliary, that suspend or alter irrigation operation during unfavorable weather conditions shall be required on all irrigation systems, as appropriate for local climatic conditions.
What You Need to Know About Irrigation Controllers to Pass the California Supplemental Exam for Landscape Architects
- Automatic irrigation controllers are required
- Irrigation controllers must use current or historic weather data to adjust schedules
- Rain sensors should be used to suspend irrigation during rain
- Soil moisture sensors can be used to replace weather data and rain sensors
- Automatic irrigation controllers (when properly programmed) help conserve water by applying the right amount for plant health based on climate information
For More Information on Regulatory Agencies:
- Part 1: Introduction to Regulatory Agencies on the California Supplemental Exam
- Part 2: US Army Corps of Engineers
- Part 3: Federal Emergency Management Agency
- Part 4: United States Fish and Wildlife Service
- Part 5: California Department of Fish and Game
- Part 6: California Environmental Quality Act (CEQA)
- Part 7: California Department of Food and Agriculture Noxious Weeds
- Part 8: Irrigation Controller Requirements – CALGreen and Model Water Efficient Landscape Ordinance
If 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.