Smart tech could save billions of liters of water

LONDON (Reuters) - Americans can save some of the 225 billion gallons of water (852 billion liters) wasted each year through over-watering by installing smart systems which deliver just the right amount of moisture.

Sprinklers spray water on grass in Los Angeles June 29, 2007. REUTERS/Mario Anzuoni

Homeowners and companies over-water their grass and plants by between 30 and 300 percent, said Chris Spain, chief sustainability officer at water management company HydroPoint, citing a report by the American Water Works Association.

“The reason for the waste is because of dumb technology,” Spain said. “There are 45 million irrigation systems in the U.S. (controlled) by simple timers. They do a great job of keeping time but a lousy job of irrigating to what the land requires.”

City landscaping, or “urban irrigation,” makes up 58 percent of urban water use, Spain said, adding that the water wasted generates over 544,000 tonnes of greenhouse gases annually.

Smart irrigation systems are programed to optimize water use based on parameters including plant and soil types and amount of sunlight, and also feature weather sensors that monitor soil moisture levels following rainfall.

“U.S. water-related energy use is at least 521 million megawatt hours a year -- equivalent to 13 percent of the nation’s electricity consumption,” said a River Network Carbon Footprint of Water report published in May.

“The carbon associated with moving, treating and heating water in the U.S. is at least 290 million tonnes a year.”

Climate change also affects water levels, with western states experiencing their driest years since records began.

This year marks the third of drought for the most-populous state of California where lawmakers are urging residents to take shorter showers and water lawns less frequently to cut consumption a fifth.

Several studies found that smart irrigation systems command water savings of between 16 and 30 percent over traditional timer-based controllers, which come at a similar cost.

“It’s not like solar, lighting or other systems which require vast infrastructure changes,” Spain said, adding that his clients have saved $75 million in water cost savings.

Jennifer Riley-Chetwynd of Rain Bird said her company saw a corporate headquarters nearly halve water used for irrigation from 416,000 gallons per year to 214,000 gallons.

Over-watering also pollutes and damages buildings, drawing $375 million in insurance claims in California in 2005, according to the California Insurance Association.

New California legislation makes smart irrigation controllers mandatory for new properties from 2012, Spain added.


The United States is not alone with concerns over water.

A joint study published on Wednesday by the UK’s Energy Saving Trust and the Environment Agency warned that as new homes became more and more energy efficient, hot water use could overtake heating as the main cause of carbon emissions.

“Six percent of the UK’s annual carbon emissions are related to water use -- nearly 90 percent of that is from hot water use in the home,” the report said.

Britain’s Environment, Food and Rural Affairs Select Committee also issued a report on Wednesday to water regulator Ofwat warning that water scarcity will become “an increasingly critical issue in the South and East of England” and urging improved water efficiency

Editing by William Hardy