The irrigation system for the master-planned community of Harlan Ranch makes water conservation its top priority.
With beautiful, lush, green landscapes stretching across this master-planned community, Harlan Ranch encompasses the true meaning of a neighborhood coupled with an exquisite style of living.
Located on the northeastern part of Clovis, CA, Harlan Ranch is a 400-acre master-planned community currently being developed by premier homebuilders Wathen-Castanos Homes and Wilson Homes. With 1,800 homes, 14 parks, an elementary school, a recreation center, and local commercial businesses, Harlan Ranch bills itself as the ideal place to call home. It is the first master-planned community to be built in the city of Clovis, which is just outside of Fresno.
Landscape architecture firm Broussard Associates of Clovis designed Harlan Ranch’s green spaces hoping to create a community that promotes an inviting atmosphere and gives residents a restored sense of community. When Broussard Associates began designing the irrigation system for this master-planned community, water conservation was top priority.
“Going into this project, we wanted to be proactive and be ahead of the game,” explains Terry Broussard, principal of Broussard Associates. “We learned that lawn care accounts for a large percentage of outdoor water use and that up to 60% of that water is wasted. By installing water-efficient irrigation products at Harlan Ranch, we’ll be setting an example for others to follow and raise awareness for the importance of water conservation.” Broussard Associates knew there were challenges going into the project. From a landscape irrigation perspective they were dealing with poor soil quality, much of it comprising heavy clay and sandy loam, that doesn’t allow for sufficient water absorption.
Because of the low water pressure in the Central Valley, Broussard Associates developed a master pump system that allows the firm to water large landscaped areas through specific water windows. Broussard Associates selected variable frequency drive (VFD) irrigation pumps, which were common on golf courses a decade ago but have become more economical to use in commercial applications. The VFD pumps save power as well as water costs because they will ramp up to supply water to designated outlets rather than totally powering on as would the old-style centrifugal-style pumps.
“With new technologies, with computers at the helm, we don’t need that motor to run at 100% no matter what,” states Glenn Bowlin, CID, CIC, CLIA, CGIA, the irrigation manager at Broussard Associates. “We only need it to handle what we’re doing, and that is a savings in itself.”
The initial expenditure for a VFD pump station may be up to 35% more, but according to Bowlin, that expenditure is usually paid off with three to five years of power costs alone. In terms of long-term maintenance and integrity, the part of the system that requires the most attention is the pump station electronics and the central control station computer. Even at that, the actual maintenance period for the pumps lasts five to 10 years with normal usage.
By using one meter and one pump that takes the place of perhaps half a dozen meters, backflow preventers, and 30% to 40% additional valves, it allows the community to water large areas more efficiently. It also provides steady water pressure to the spray heads, which are equipped with pressure-regulating stems, at a preset level of 30 psi.
All together, Harlan Ranch has 80,000 570Z-PRX-COM-E spray heads; 300 TR-50-4-COM-E rotors (featuring X-Flow shutoff feature and TruJectory adjustment from 5 to 25 degrees, thus eliminating overspray); 2,000 P-220-26-RW60 Toro valves; and 50 Sentinel field satellites with the Toro central control system with a dedicated Davis weather station. The heavy-duty P-220 valves are designed for commercial applications with pressures up to 220 psi but also have the ability to pressure regulate the flow through the valve anywhere from 5 to 100 psi.
In addition, each of the 2,500 trees in the common areas has its own underground bubbler so that it is watered at the root level.
To keep water from pooling up, each sprinkler on the site is equipped with a check valve whose purpose is to shut down all of the sprinkler heads, no matter what amount of water is in the piping system, as soon as the valve shuts off, thus saving the remaining water rather than having it trickle out.
“All of our sprinklers and rotors are pressure regulated, and with the PRX-COM spray heads, we do not anticipate a waste of water onsite,” Bowlin says, adding that while the PRX line may cost two to three times more than a typical spray head with a pressure regulator or stop valve, there is a significant payoff when it comes to performance and water savings. “The HOA [homeowners’ association] areas are watered with reclaimed water, and we felt that the Toro product will do a great job with this type of water.”
ET Lands at Harlan Ranch
From the outset, Broussard Associates made it a goal to install a highly user-friendly and reliable irrigation system at Harlan Ranch since the homeowners’ association would eventually be taking over maintenance chores. Each of the custom-built homes will also be equipped with a Toro Intelli-Sense controller that uses two technological advances to increase irrigation convenience and save water.
First, it incorporates WeatherTRAK scheduling software, developed by HydroPoint Data Systems Inc. of Petaluma, CA, to automatically calculate the optimum irrigation schedule based on a series of self-prompting questions answered upon installation. Variables include sprinkler type, precipitation rate, efficiency rate, soil type, plant type, root depth, microclimate, and slope factor.
Next, Intelli-Sense controllers receive daily weather updates gathered from weather stations. WeatherTRAK accesses more than 18,000 professionally maintained weather stations across the country that are relied upon by the National Oceanic and Atmospheric Administration’s national weather service. The information is analyzed and converted into location-specific evapotranspiration (ET) data (accurate to 1-square-kilometer grids) and transmitted to the WeatherTRAK wireless network.
The WeatherTRAK scheduling engine utilizes a simple and recognized approach to developing an accurate watering schedule. The software automatically generates station-specific programs for unique combinations of plant, soil, slope, and microclimate. Programs include water days, watering duration, and multiple soak and run cycles to ensure that plants get the water they need when they need it.
The scheduling engine first walks the installer through a series of questions about the landscape. Built-in sprinkler, soil, and plant databases make programming easy. Based on the answers provided, the scheduling engine then automatically calculates an irrigation schedule for each landscape zone. Users may also customize any settings including water days and times to meet city regulations and customer requirements.
“These controllers are light years ahead of what we used to use. With each and every station, you program in the type of plants, turf, and soil whether or not there is a slope and the exposures,” Bowlin says. “You’re ready to go as long as you trust the technology.
“Instead of turning on all the zones for 20 minutes and just letting them water, this system is actually doing the thinking for you based off of weather. You may walk through the backyard and think, ‘Man, this is dry,’ but really it’s only dry today because the system is going to water that night based off sun exposures, wind conditions, et cetera. It’s a leap of faith.”
The data so far have been more than reassuring. The Intelli-Sense controller scored 100% in irrigation adequacy with no excess during Smart Water Application Technologies performance analysis administered by the Center for Irrigation Technology at California State University–Fresno.
What Is ET?
Evapotranspiration, also called ET, is the amount of water used by a particular plant species (through transpiration) plus the amount of water evaporated from the surface of the soil under measured weather conditions. These amounts are typically accumulated for short time periods, such as a day or a week, and then expressed as an amount of water that would be needed to replace the amount used.
According to the California Regional Water Quality Control Board, the average evapotranspiration rate for the Central Valley region is approximately 48 inches annually.
“We’re trying to get people to understand that ET is something other than what they saw in the movies,” jokes Chris Steele, senior specifications sales manager with Toro, the company that installed the Harlan Ranch system.
“Just as the cost of gas has made people go out and buy hybrids and reduce the size of their cars, the cost of water is going to demand people to start paying attention to conservation.
“Because everybody in this area uses fescue grass lawns, we have 100-plus-degree weather in the summertime, and a lot of the soils are heavy clays with some amount of slope, everybody tries to dump the water into three days,” he adds. “The majority of what they’re doing, with spray heads especially, is running long cycles of 30 minutes or more, and after the first few minutes it’s all running down the gutter.”
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Photo: Broussard Associates |
| High-tech controllers blend into new housing developments. |
Steele estimates that in the city of Fresno, for instance, where single-family residences are used to paying a flat rate for an unlimited amount of water, most homeowners are watering 400% to 500% over ET.
Landscape professionals, however, recognize that overwatering is expensive, unnecessary, and harmful to landscapes. Unfortunately, few current technologies provide solutions to help customers avoid overwatering.
One of the biggest questions was whether home developers would buy into the new technology and install the high-tech controllers from the beginning of the project and not just make them an option. Smart controllers have been around for a decade or so, but what’s new is that prices are becoming more affordable.
In an interview with the Fresno Bee newspaper, Kevin Castanos of Wathen-Castanos, one of the two developers of Harlan Ranch, says that if he’d been planning the development five years ago, he probably couldn’t have justified the cost of such a high-tech system.
What he likely would have otherwise put in would have been an average low-end controller that typically costs under $50, whereas the smart controller represents a substantially larger—around $200—investment.
Luckily, developers on the project were concerned about water conservation from the start as the Central Valley is an area where water conservation is becoming a high priority. A recently passed California law also calls for all new landscape irrigation controllers sold and installed by 2012 to be what the industry calls smart controllers.
“There was no budget restrictions, per se; it was a matter of doing things right and moving on,” says Bowlin, adding that through phase I and phase II of the Harlan Ranch project, the irrigation costs have totaled close to a couple of million dollars.
Castanos is quoted in the Fresno Bee as saying that he couldn’t make any hard predictions about how much water the new system will save: “I think the proof of that will be after we’ve been online for a year.” But he says he’s sure there will be long-term benefits—and not all can be measured in dollars.
“I’m not going to look to government to guide me,” he says of the new state law. “I wasn’t even aware of that regulation. Philosophically, I’m looking for sustainable issues.”
According to HydroPoint, multiyear studies consistently demonstrate WeatherTRAK’s ability to capture 85% 95% of the savings potential at any given site. This has yielded outdoor water savings of up to 59% for both commercial and residential properties. Studies have also shown that correctly using the technology can result in a 71% runoff reduction.
But there’s more to it than just plugging in the controllers and waiting for the water to come on. To make the smart controllers work correctly, the actual irrigation system itself has to be installed properly; sprinkler heads have to be adjusted accurately, and valves must be kept operational. It’s the contractor’s job to install the heads and piping system based on the landscaping that’s planned.
As Bowlin points out, “A sprinkler is a sprinkler, and a valve is a valve,” so for the most part the in-ground components of the irrigation system can be maintained by any knowledgeable landscape contractor. The developers are very open to supplying contractors with plans and specs because the irrigation systems have been engineered to apply water in an exacting pattern.
“Hopefully they’re following microclimates, such as watering the north side of the house separately from the south side, and making sure that shrubs are watered separate from the turf,” Bowlin says, adding that one benefit of the WeatherTRAK system is that no in-ground sensors or other special equipment is required.
As part of its deal with homeowners, Wathen-Castanos will cover the first year’s $48 service charge for HydroPoint’s weather tracking system. The clock does have the ability to run as a manual controller should the user wish to discontinue the ET feed. The development’s public facilities and greenbelts will stay connected regardless.
Sustainability Is the Key
Steele points out that if someone puts off-the-shelf irrigation devices in his or her home or yard that need to be maintained, whether it’s a mini weather station or a moisture-sensing apparatus, it’s a good bet that it won’t be working longer than a year.
“People don’t even change their controllers half the time, let alone maintain another device in the ground,” Steele states. “With the HydroPoint/WeatherTRAK system, you set the controller and fine-tune it, and then you pay for a service where you get true ET information 365 days a year.”
Other than having a full-blown professional-quality backyard weather station, which is impractical for homeowners, Steele says the WeatherTRAK technology is as accurate as it gets.
Toro, which incidentally was the first manufacturer to come to market with an ET-based controller, is in the process of releasing commercial versions of its Intelli-Sense controllers that are capable of handling up to 48 stations. The advanced units will also have flow-monitoring capability, and eventually the pager transmission technology will be two-way where users will be able to remotely monitor water flow.
While turning over control to an automatically programmed technology might sound like science fiction to some, Bowlin expects that after a short time it will become a fundamental part of homeowners’ lives.
“Remember how when everyone got VCRs and DVDs, they were a little intimidating because there were all these buttons and controls? Then along came TiVo, and it pretty much wiped out VHS and DVD because you program your TiVo, and it downloads the shows for you. It’s a mindset,” Bowlin says.
“We’re showing things that are going to be standard within five or six years. It’s not like this technology was invented last year and we’re doing it this year and, like the new Microsoft Windows, it’s going to crash on us; this is something that’s been around for at least a decade. We’re not trying to reinvent the wheel; we’re just trying to apply quality technology where an average person can benefit.”