With water in short supply, and high demand nearly everywhere throughout the world today, water is looked upon as more valuable than oil; without it hard choices will have to be made. The “no need to worry, there’s lots of water” mentality is a mind-set that is taking a long time to undo. For as long as anyone can remember, water has been misused, mainly due to wasteful practices. Although not intentional, these practices have to change. Over the past few years, new technology was developed to help conserve the use of water. Now, this new technology is available for even the smallest piece of property. Enter the new era of irrigation controllers -- SWAT and WBIC.
These are acronyms created to sum up what the new ET controllers can do to save water. “Smart Water Application Technology (SWAT) is a national initiative to achieve exceptional landscape water efficiency through the application of irrigation technology,” states the IA (Irrigation Association) website. Weather-Based Irrigation Controllers (WBIC) are also known as smart controllers. The information that is fed to the controller comes from variety of sources, depending on the manufacturer. It can include an onsite miniature weather station, sensors, an ET signal sent via satellite, the internet, or microwave (think cell phones). ET is the acronym for evapotranspiration.
WBICs gather information such as weather conditions, soil moisture, and plants’ evaporation and transpiration rates. They can monitor and use the information received to decide when to water and when not to, providing the exact amount of water needed to maintain, lush, healthy growing conditions.
Currently, the IA is testing controllers and formulating a reporting process that will give meaningful information to professionals and end users alike, much like the Energy Star rating that exists on electrical devices. Although the final SWAT rating system has yet to be determined, the goal of the program is to identify water efficient controllers and sensors.
The concept of ET has been around and in use on a larger scale for more than 15 years. Today, the new era of controllers featuring ET are aimed directly at the residential marketplace; the millions of users of low water consumption, that when grouped together, create the largest users of water.
Photo courtesy: Aqua Conserve
As water becomes more expensive, and water shortages compel municipalities to restrict the use of water for the landscape, it is hoped that property owners, especially homeowners, would consider upgrading their existing controller to a smart controller.
Equally as important, using a smart controller will provide beautiful gardens, healthier plants, less damage to driveways and walkways, and higher real estate values. Another benefit would be a typical savings of thirty percent on your water bill (this should help offset the cost of the upgrade). The environment would also benefit, with cleaner streams, rivers, lakes and oceans due to reduced run-off. When you know that your life or the lives of others depend on the water we save, wouldn’t the neighborly thing be to upgrade to the new technology? Smart irrigation controllers reduce water use by “watering with the weather – not by time.”
ET is a number, say a quarter of an inch, which represents how much water was used up, evaporated from around the plant or transpired from the plant’s surface today. If we have a storage area (soil plus the roots are known as the root zone) which will hold one inch of water (known as available water holding capacity) waiting for the plant, and an irrigation system that can only supply a quarter inch per day, and -- here’s the cruncher -- we say that the water in the soil cannot be depleted more than fifty percent. You can say that at this quarter inch daily loss rate, we need to water every third day to keep the soil reservoir topped up.
Smart irrigation controllers have proven to reduce water usage in pilot projects conducted during the past four years. They can reduce outdoor water use by responding to real weather conditions -- if it’s hot the controller waters, if it rains it stays off, if it’s cloudy maybe it will postpone the watering until tomorrow or, if the total amount of ET adds up to more than fifty percent, it turns on. This is a rudimentary look into how they work.
WBICs have proven to work admirably. A system priced in the $600 range has proven to perform very closely to a full-scale central control system with a full-size weather station, priced around $20,000--a remarkable achievement by the manufacturers who have produced some remarkable technology at rock-bottom prices.
In some water-scarce areas, incentive programs are being created, paying up to fifty percent of the cost of the upgrade. Others, like the San Diego County Water Authority, are offering a residential voucher incentive of $65 per controller, and a business voucher for $13.33 per active station, up to 48 stations.
The Environmental Protection Agency has embarked upon a star, actually a Water Star program, to help consumers identify efficient water-use products. The Smart ET WBICs will certainly qualify for a star or two. The Irrigation Association sums it all up by noting that, “Smart controllers will change the way Americans water their landscapes.” It will also do the same for all of North America, plus wherever the new era technology is correctly applied.
Ensuring that these controllers properly perform in the field, each controller must pass an eight-step test developed by the Center for Irrigation Technology. A few manufacturers offer only larger single to multi-site irrigation system ET controllers. Others require sensing devices to be purchased separate from the controllers.
In many places, water is a finite resource; and that list is growing. How we manage this precious commodity will ultimately effect if, and when, we run out. With the technology now available, saving water has never been easier. All it takes is the right controller, and you too can be “smart” and use water wisely.
Editor’s Note: Lorne Haveruk is president of Water Management Services, and is an irrigation water efficiency consultant and certified irrigation designer, contractor, auditor, and water conservation practitioner. You can contact him at firstname.lastname@example.org or 877.H2O.WISE.