Okotoks water irrigation
By Blair Braitenbach
Staff reporter for Okotoks Western Wheel
August, 2007

With the introduction of a new weather based irrigation system, town councillors hope to further establish Okotoks as an environmentally sustainable municipality.

At the Monday, Aug. 13 regular town council meeting, councillors were given a presentation on the weather-smart watering system by Graham Duffy, CEO of ExactET. The new system is being undertaken as a pilot project in Okotoks to “test the water management and conservation capabilities of converting conventional timed landscape irrigation systems to weather based smart irrigation controllers,” according to the report presented. In total 10 Okotoks parks have been outfitted with the controllers, however, how well they have been functioning will not be known until a report is filed at the end of the growing season.

Town Councillor Ed Sands said he is in favour and excited about the new system.

“This is one of the things when we look at capping the population… that as we have technological advancements they will assist us to live within our means. Moving ahead with things that weren’t in existence when we made our initial vision, we’re able to achieve success,” Sands said.

According to Darren Kovacs, co-founder and chief operating officer of ExactET, during the summer people’s water consumption doubles, almost entirely because of irrigation. But what the weather based watering system does is calculate the amount of water in the soil, thereby determining whether or not the grass needs to be watered. Kovacs said the water system basically works like a fuel gauge in one’s car.

“People don’t have a gauge with their landscapes and the tank is the soil reservoir. So they’re filling it (the soil reservoir) up regardless if it is full…What this system does is it only fills what it needs to fill rather than overflowing,” Kovacs said.

So say one’s gas tank was three-quarters full and only needed $10 of gas, over watering when it’s not needed is like putting an additional $75 in, according to Kovacs.

“It’s automated. Rather than having to go to the gas station, your car basically drives itself to the gas station,” Kovacs said when comparing the water system to a car.

How the system specifically works is weather data is collected in “real time” through a central server and sent wirelessly to each ET manager. The information states the amount of moisture used by the plants (transpiration) and the moisture lost from soil through evaporation, together called evapotranspiration or ET. Irrigation is only conducted when soil moisture levels are low and when there has been a lack of rainfall. According to the ExactET report, when watering is conducted only when the soil reservoir is empty, not only is up to 60 per cent of water conserved, but plant roots grow deeper creating healthier plants and a greater resistance to weeds. Kovacs pointed out that this system reduces the amount of “nutrient leaching” due to over watering. With 10 properties using the existing system in Calgary, Kovac said last year alone 4.5 million gallons of water was saved.

ExactET is working with the town’s bulk water manager, EPCOR, so in the event EPCOR needs to scale back the amount of water being distributed in an emergency situation, such as a water main break, they can do so.

This weather-based irrigation system is used in Calgary, Vancouver, Kamloops, Edmonton, Ottawa and the greater Toronto area.
The program has cost the town $25,000 for the trial period to date.