A crucial life and economic resource is becoming increasingly endangered, yet just about everyone takes it for granted. That precious resource is water.
Just about every part of this country has experienced a water supply crisis. Long before water runs out, there will be certain restrictions on the use of water in the landscape. There will also be steep increases in the price of water.
Since it has been so abundant in our nation’s past, the notion of running out of water in the U.S. rarely came to mind. Even now, as the occasional city imposes restrictions on water use, it causes little more than an annoyance to the general public. But, consider:
Population growth in cities around the Rio Grande River in the Southwest is expected to outpace the available water supply before 2025, despite conservation and reclamation projects. The expected population of the El Paso/Ciudad Juarez area, for example, in 2025 will be six million. With all the conservation efforts underway, the water supply will be able to support four million people — at most — and that would be in years with normal rainfall. (U.S. Water News Online)
China lacks more than 30 billion cubic meters of water every year, which causes $28 billion of losses in industrial output. More than 400 cities and 20 million people in China face the problem of water shortages. Yet, pollution and waste of water can be widely seen in many places. (People’s Daily)
The World Bank reports that 80 countries now have water shortages that threaten health and economies. (Arizona Water Re-source)
We can feel fortunate in the U.S. that the water issues that we face are not life-threatening in the foreseeable future, as they are in other world locations. However, the U.S. Census lists our population at the New Millennium at about 275 million. In 2050, the agency expects us to top 400 million. Just like other places around the world, the problem is going to first hit us economically.
A complex solution Various irrigation manufacturers have taken the issue to task and achieved good results in designing new technologies for water conservation. Other manufacturers are achieving water conservation in other ways. The word is slow to get out, however, in that most of the industry considers the issue to be . . . well, complicated. Some of the manufacturers of the new technologies base their products around ET, which stands for evapotranspiration, a technique of measuring six or seven variables regarding plants: temperature, humidity, sunlight, radiation, wind, and rainfall. These are put through an equation to figure out how much water is lost from the root zone during any one period in time.
Soil type, sprinkler type and slope are additional supply variables needed to factor into any calculated schedule. Once you have that information, you can figure out exactly what kind of watering schedule is perfect for your plants. Many companies have worked with ET for the last 40 years, and have, in recent times, used the information to schedule irrigation controllers. However, there are several problems with ET, one of which is finding the right formula to use. “Experts have argued about which is correct,” says Mike Miller, founder of Baseline Systems in Boise, Idaho, “because there are four or five of them, and you also have to know what plant you’re dealing with. Different plants evapotranspirate at different rates.”
The bigger issue that slows the growth of ET is that these calculations change, not only with the landscape, but with the weather. Then, once you have all of the watering information for your particular plants, you have to schedule this watering program into your irrigation controller. Dave McLeroy, of Green Leaf Mapping & Control Systems in Cupertino, California, maintains that scheduling the controller properly is too time consuming, especially for busy professionals. “When proper watering is critical to landscapes,” says McLeroy, “It’s in the middle of summer and contractors have many other crises to deal with. They’re probably short-handed in their peak season, and don’t have assistants qualified to even operate the controller, much less calculate the schedule accurately.
So, they wing it, or use the standard settings over and over.” That is, of course, if they do it at all. Miller says that some ET companies have done internal studies and found that within three years, 65% of the ET systems in use are either turned off or not used.
“And they are just expensive clocks,” he says. Just about everyone agrees that overwatering takes place, especially in the residential area. Great amounts of water are wasted, simply because few people take notice or care how much is really necessary. Professionals don’t have the time, or don’t make it a priority to develop good schedules. Miller conducts and reviews others’ studies in water use, and recalls a study that showed 300% overwatering for residential landscapes. In commercial sites, the overwatering rate is between 200 and 400%.
“That’s an average,” he notes, “which means that while some are down where they should be, some have to be at eight to ten times what they should be . . . that’s a lot of water.” Computing some solutions So, now, computer and Internet technology have come to the rescue, and have produced several types of ET products that change the way ET scheduling is done. The equations have not changed, but the ease of putting them into action has improved dramatically. Many of the latest advancements in ET offerings are intended to make the scheduling process easier, so that the landscape contractor, facility manager or homeowner doesn’t have to even think of the calculations at all.
The approaches to how this is done vary from company to company. HydroPoint Data Systems, located in Petaluma, California, takes U.S. weather information and calculates it for specific areas of the country. “What we’re doing,” says Chris Spain, HydroPoint’s CEO, “is creating virtual weather stations over every part of the country.” Then the company wirelessly broadcasts the weather information to each controller and their location-specific ET (which the scheduling engine takes and adjusts scientifically), to accommodate for the local weather. Users of HydroPoint’s controllers program them for “hydrozones.”
The size of this zone is determined by the variety of and consistency of the plants in the zone, and by the distance that you feel comfortable pumping the water, based on available water pressure. Users can even get alerts about their landscape, and also make adjustments to the schedule, using a PDA (Palm Pilot-type device) or a computer. Aqua Conserve, in Riverside, California, on the other hand, sells controllers that have the ET calculations built in. Gary Bailey, Aqua Conserve’s marketing manager, says that one of the best features of his company’s controllers is that it need only be programmed once. A user is instructed to input the appropriate watering schedule for the month of July.
Then, the controller takes over, adjusting the schedule as the year goes along. To figure out the modifications, the controllers are preprogramed with 10 years of historical data for various regions on plant water use for the year. This data is used by the controller to self-adjust the scheduled watering run-times twice each month.
When the temperature sensor is installed, the run-times are adjusted daily. Green Leaf Mapping & Control Systems offers a complete landscape management package, which includes irrigation management. Their software, accessible from any computer connected to the Internet, makes collecting data and documenting the savings an easier task. “We do all the calculating; all our clients do is add more water where we show red and less water where we show blue.”
Dave McLeroy, president of Green Leaf says, “Our software is used to develop good base schedules and logically prepares any property for ET-based clock installation.” Another high-tech offering is the controller from ET Water, headquartered in Mill Valley, California. It produces a system whereby a user would input the different aspects of his landscape on the Web, using a graphical user interface (GUI), an easy, visually-oriented type of computer program. Once the details of the landscape are put in, ET Water uses weather stations in the user’s area to track the weather, so that the watering schedules are changed automatically. Users would replace existing controllers with similar ones made by ET Water, for use with the system. Bruce Cardinal, president of ET Water, maintains that the ease of use with the computer program makes for more reliable data being entered.
“The use of a GUI that provides pictures and help,” he says, “is essential, because, like any system, if you put garbage in, you get garbage out. So, all the user has to do is be able to reasonably describe their landscape.”
A more sensitive approach Not all of the new, water-saving technologies available today require ET information. Several companies, such as Miller’s Baseline, use moisture sensors, instead, to determine when the water should be applied to the ground. Miller says that this technology has been around for decades, but to this point, the equipment required to do it has been faulty and expensive. To use Baseline’s system, the user will measure moisture thresholds. “There are two thresholds with regard to plants,” says Miller.
“One is where it can’t get enough water and dies (called the wilt point) and the other is where it can’t hold any more water (the field saturation point). Plants must live somewhere in between.”
That area is called the field capacity. When the sensor determines that depletion of water in the ground goes to below 50%, it ensures the water gets replaced. In addition to
Baseline, there are a number of moisture sensing device companies marketing to the irrigation industry. One of the oldest soil moisture sensor companies, Irrometer Company, Riverside, California, has been around since 1951. Their sensor devices work in conjunction with conventional controllers to override the controller when irrigation is not necessary.
For more complex landscapes, the company offers software that calculates the irrigation schedule and recommends the moisture level, based on general information about the site that the user selects. Other companies offering moisture sensing devices include H2O Strategies, Inc., Manhattan Beach, California and Dynamax, Inc., Houston, Texas. Regardless of the technology and how easily and automatically it may make adjustments, each manufacturer recommends that the user keep track of what is going on with the landscape to determine whether adjustments need to be made. “Periodically, you must evaluate the results yourself,” says Miller.
“You have to ask yourself, ‘Is this system doing what it needs to do? In other words, is my landscape too dry or too wet?’ Then adjust the system appropriately.” The wonderful thing about these technologies is that, even though there may be some differences in the water savings, the mere attention to scheduling the watering appropriately will save water, and a great deal of it. Just paying attention to, and altering, the watering schedule at all will save water. “I can show someone how to save 20% of their water just by changing the watering schedule four times a year, according to the seasons (once in spring, once in mid-summer, and twice in the fall). Adjust it every week and the savings can go up to 70%,” Miller maintains. Paying off in different ways While saving water certainly benefits humankind, the savings can quickly translate into real money, especially where water is expensive.
McLeroy claims that, in California, for example, a customer may pay nearly $1,000 per month for the wet stuff. Changing to one of these technologies has some other monetary benefits, too. Many municipal water agencies offer rebates and incentives to property owners who use these new technologies. However, some agencies and regions of the country value certain technologies more than others, so you had best check with the one in your area. On the opposite side of the equation, if you don’t manage water wisely, you could get in trouble with municipalities, McLeroy points out. “A potential risk of overwatering,” he warns, “is that clients may be fined if pesticides, nitrates and other material, are washed into the storm sewer drains. The fines can be stiff for property owners, and the landscaper ends up being the bad guy.” Technology is marching forward, but public awareness, knowledge and acceptance are still lagging behind. The key to this equation is you, the contractor. You need to take a little time and really find out if ET can work for you. It may take the eventual scarcity of water to push the marketplace to finally gain “Water Wisdom.”
By BRUCE BLAU