An Easy Way To Find Your Exact ET!

We've covered Evaportranspiration Rate a few times already. We've defined it, and have demonstrated how it is used in the field. There's many options available to help you figure out your ET, but one that has intrigued me for a while, a website called, is cost effective, accessible and an easily understood option. This is why I asked the Turfhugger "Irrigation Guru" Daryl James to track down Graham Duffy, CEO of, to find out more.

Turfhugger - We love talking ET on, tell us a little more about:

Exact ET - Firstly, thanks Turfhugger for inviting us to talk about ourselves and more importantly about ET. ExactET is dedicated to efficient water management and water conservation. We have for many years seen huge waste in the urban landscape irrigation market, in large part due to the use of timer-based irrigation and the programming of those timers to over water. ET based water management has been around for years and has been available to large water users such as golf courses and municipalities. However because of the economics it was not really available to the residential and commercial landscape irrigation markets. That is no longer the case today with the technology available. Just as importantly water conservation was coming to the forefront of the Canadian psyche – municipalities and consumers were starting to look at ways to conserve water (e.g. low flush toilets, low-flow fixtures). ExactET was born.

Turfhugger - How did you become Canada’s Leader in Climate Controlled Irrigation?

Exact ET - Like all great companies, through a strong clear vision, a passionate management and staff, and a determination to succeed. I like to borrow a page from the Ted Rogers’ (Rogers Communication) playbook when he built a very strong Cable backbone across Canada. We early on saw the importance of building a highly accurate and extremely reliable ET weather monitoring network – a network that delivers hourly ET information, with the results trackable online. Today we have over 40 ET monitoring weather stations strategically located in Canada’s major urban areas – from Vancouver in the west to Montreal in the East. The weather stations are specifically designed for ET water management and are manufactured by the leader in weather stations, Campbell Scientific.

Turfhugger - At present, you’re working mainly with residential and commercial properties, can you give some insight to how watering ET may help Superintendent’s water more effectively?

Exact ET - A great question. The best way I can answer this is to quote one of the leading Golf Course Superintendent’s in Canada who we work closely with, Thom Charters, Bayview Golf & Country Club. Thom’s response when I am asked him the same question was "Irrigating turf and landscapes is not an exact science. It is easy to apply more water than is actually required and rarely do I see properties with automatic irrigation systems displaying symptoms of drought. Over applying water is costly and potentially detrimental to maintaining a healthy, sustainable landscape. Watering, based on evapotranspiration (ET) rates is not only cost effective but environmentally responsible. Our weather station provides information that is factored into our irrigation decision making process daily and we are better resource manages as a result."

Turfhugger - What are the long-term goals for

Exact ET - To grow the adoption of climate based (ET) irrigation across Canada and in so doing promote efficient outdoor water management, saving potable water and saving CO2 used to treat and pump that potable water.

Turfhugger - Do any golf courses use your services to improve any irrigation around their clubhouse or gardens?

Exact ET - Our residential and commercial systems are really designed for that market. We do however directly input our ET data into Central Control Systems, similar to the ones used by golf courses, avoiding the need to purchase a complete weather station. I am also aware that a number of golf courses have gone on our website ( ) to view our ET data and use it in their irrigation decision making process rather than purchasing their own weather station.

Turfhugger - What are the benefits of climate-controlled irrigation?

Exact ET - For our many clients climate based irrigation saves significant amounts of water; saves on their water bills (many of our commercial customers experience a 1-2 year payback), avoids over watering, avoids watering when raining, is healthier for the landscape (following best horticultural practices of deeper less frequent root watering) and is environmentally responsible. By way of example one of our commercial clients in the Calgary market, Sunridge Business Park saved 14.3 million liters ($21.9K in water savings) while maintaining a healthy green landscape in 2008 by converting to climate controlled irrigation.