Controllers can run existing systems.

A new law in California aims to reduce landscaping water usage by requiring that all non-agricultural irrigation controllers sold or installed after Jan. 1, 2012, meet strict conservation performance standards.

The legislation passed with broad support from environmental groups, landscape and irrigation interests and local governments, including the Association of California Water Agencies and the Sierra Club. The California Dept. of Water Resources will now develop a model ordinance for local adoption.

The move is expected to be a boon for companies providing irrigation management products, such as “smart” controllers that monitor weather and factor in plant water use and soil evaporation.

Several companies, including Aqua Conservation Systems, Riverside, Calif., and Dallas-based Weathermatic, offer site-specific, sensor-based controllers. Another company, Hydropoint Data Systems Inc., Petaluma, Calif., offers a national subscription system that adjusts watering at sites around the country by using daily weather updates, customized down to a half-square mile area, transmitted to them wirelessly.

The data considers predicted local temperature, solar radiation, wind and humidity levels, as well as landscaping details provided at installation by the customer. The WeatherTRAK controllers are set up once and then adjusted with wireless input from then on.

“Studies show customers are seeing water savings of 20 to 40%,” says Chris Manchuck, Hydropoint’s vice president of business development. Outside studies by the U.S. Environmental Protection Agency and others show the technology can reduce runoff by more than 70%, the company reports. Each $1,500 controller can manage up to 48 zones. Subscriptions range from $4 to $7 per month, depending on the number of controllers.