Greener Grass

A Calgary company brings urban irrigation into the information age

by Stephanie Sparks

You decide to fill up your vehicle’s gas tank, whether it needs it or not, every Monday, Wednesday and Friday. You’re not concerned about the money lost or the fuel wasted – you just don’t want to neglect your vehicle should you give up this schedule.

This is the analogy ExactET Systems Inc.’s co-founder and CEO, Graham Duffy, uses to explain the need for “smart” climate-controlled irrigation systems – except think water conservation instead of fuel. Timer-based systems, he says, are “glorified clocks.” ExactET’s technology, by contrast, decides whether the grass really needs a sprinkling.

“With global warming, water becoming a scarce resource and the demand for water conservation, the irrigation industry is in a real state of change and is starting to focus on how do we water efficiently,” says Duffy. Seeing a business opportunity in the emerging climate-controlled irrigation industry, he and irrigation specialist Darren Kovacs founded ExactET in 2005.

ExactET works with 38 irrigation specialists across Canada, providing them with data collected through an expanding network of weather stations the company operates. ExactET’s system then analyzes this evapotranspiration (ET) data and triggers clients’ on-site sprinkler systems only when required. Similar technology has been used by golf courses and municipalities for years but is not yet common among residential and commercial properties, the company’s target market.

“Typically what happens is most people set their irrigation to a three-day-a-week cycle, which really covers the heat of the season, the July time, when you really need three-day-a-week watering,” Duffy explains. “The rest of the time [when it’s cool and overcast], you often don’t need it.

“The average over the last three years that we have seen from the ET systems is we’re watering anywhere from 25 to 35 times a season. If you’re on three-day-a-week watering, you’re watering usually 66 times a season. Right there you can see there’s a 50% water savings.”

Work with Shaw Cablesystems’ Calgary-Barlow office produced water savings of 22.9% or 2.26 million litres between May to September 2008. In that same period, the Southcentre Mall, another ExactET client, recorded water savings of 59.7% or 5.2 million litres.

ExactET has 11 weather stations strategically placed throughout Alberta. These stations collect data from five sensors, measuring solar radiation, wind speed and direction, temperature, relative humidity and rainfall. Every hour, the information is wirelessly transmitted to the smart controllers, which decide when and how much to water based on criteria including soil and plant type, root depth and slope of the land.

Calgary has seven weather stations because of the city’s micro-climates. At the outset, ExactET was content to work within city limits, but staff decided “the opportunity is enormous,” Duffy says. “We’ve had a lot of interest and a lot of municipalities talking to us.” By the year’s end, the firm expects to have 40 weather stations operating across Canada.

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