Complexity Control
As water conservation managers strive to optimize irrigation scheduling, online system monitoring helps them manage increases in variables.
Achieving optimal irrigation efficiency in commercial applications is not a matter of simply implementing new technology. Two water conservation managers who recently discussed their use of optimization-enabling technologies with Water Efficiency indicated that high-tech tools do not replace sound management practices.
Scheduling irrigation according to evapotranspiration (ET) rate—the rate at which water is transferred from the earth to the atmosphere by combined evaporation of water and transpiration from plants—is becoming an increasingly common practice, and technology providers are making increasingly powerful tools available for this task. Foremost among these tools is the smart controller, which processes historical or real-time weather data variables and activates irrigation systems at the local level based on these data.
To the old axiom that information is power, however, one might add the corollary that a manager’s failure to process information variables can have a counterproductive effect. What is needed is a management tool to best manage information. An example of this is online monitoring of smart irrigation tools. This service allows water conservation managers to address operational exceptions and tweak irrigation schedules according to localized variables from one central location.
Labor Productivity Gets a Boost
Dave Blythe, recycled water coordinator with Moulton Niguel Water District in Orange County, CA, is concerned about conserving as much recycled water as possible. Local recycled water rules and regulations mandate the minimization of ponding and runoff. About four years ago, the district began utilizing Rain Master RME Eagle ET-capable controllers to help prevent waste on the roughly 80 properties that it owns and maintains. The controllers detect malfunctions in the field such as a broken head or pipe.
In 2005, the district added a significant amount of intelligence to its irrigation system by effectively networking the controllers using an iCentral control system from the same company. In the event of a malfunction in the field, the system sends a text message to Blythe’s cell phone and computer, as well as to those of his landscaping contractor.
In addition to handling these more catastrophic situations, the system helps Blythe regularly optimize recycled water use by making use of historical ET data. He could manually input these data for each controller from his computer but chooses to download the data, which are compiled on a zip code–by–zip code basis and use daily averages covering the past 30 years, from the hosted service’s Web site. In a district with varying terrain and climate like Blythe’s, these data are both powerful and beneficial.
“It’s based on zip codes and it seems to reflect the numbers that we would find throughout our district,” he says. “It’s a good happy medium to use because we’re in coastal hills, so we have a lot of microclimates. It can be foggy and drizzly toward the coast and it can be 60 degrees, and on the other side of the district, it can be 85 degrees and sunny all day—the data tend to reflect that very well.”
Blythe hopes to leverage even more powerful data by incorporating the latest weather conditions into the system starting next year. By installing the same company’s onsite weather stations near the controllers, the district will have the ability to replace historical data with real-time wind, rain, temperature, solar radiation, relative humidity, and ET data from each site.
As it is, Blythe says that the system helps him manage daily weather variables from one location and makes his manpower significantly more productive. “What I find from our landscape maintenance crews is that if they’re out working in an area, let’s say yesterday afternoon, and something goes wrong at about 3:00 in the afternoon—they’re normally off about 3:30—the supervisor gets a notification that there’s a problem somewhere,” Blythe says. “He can go over or have his crew go over before the end of the day, evaluate the situation, see what we’ve got, and if they have to stay late they can take care of the problem. Or, if it’s not a problem, it can wait until the next day—it saves them a ton of driving time, which means it’s going to get looked at immediately instead of 24 hours later.”
Also, management of Moulton Niguel Water District’s entire irrigation system makes more productive use of labor since the online monitoring capability was added. Blythe can make adjustments on all of Moulton Niguel’s controllers on any computer with Internet access after he enters a username and password. “Without iCentral, you’d have to do that out in the field,” he says. “The same with the alarms; the alarms would be stored with the controller in the field. With iCentral, we get them automatically.”
Blythe recalls when computer monitoring of controllers was available but not as flexible as it is today because the public did not have access to the Internet. “Now, a lot of manufacturers are heading this way and finding ways to give you more tools in the field, and from different computers,” he says. “It doesn’t have to be that dedicated computer—you can get onto the system at a Starbucks in San Francisco. I cannot physically visit each and every site every day. This helps me stay on top of the irrigation portion of things and reduces the call portion of the job. I still have to visit sites to do coverage tests and test plant materials, but this takes a big burden off.”
When it comes to making current weather-based adjustments to a system designed to operate based on historical data, the district yields greater water savings and labor productivity not just once but twice. “Let’s say we get into spring and it’s starting to warm up,” Blythe says. “The controllers are all on and they’re ready to irrigate. If we get a minor rain event, to get the [landscaping] contractor out there to change the settings or turn them off realistically isn’t going to happen at all 80 sites. And then to have them go back there and turn them back on [is challenging], whereas both he and I can do it from our desk or look at the weather report in the morning and say, ‘We really are going to get some moisture and let’s just go ahead and turn the system off.’ That’s a five-minute task, whereas it would take us all day to do it manually and then we’d have to go back out and do the same thing.”
Online monitoring capability is augmenting Blythe’s ability to troubleshoot system problems with the same manufacturer’s RME Eagle controller, which the district began using about five years ago. In addition to robust scheduling and ET features, one of the controller’s most useful tools is flow monitoring. Mindful that a malfunction sometimes occurs in obscure locations and can continue for days over a holiday weekend, Blythe cites the advantage of flow monitoring as a systemwide troubleshooting tool.
“We can set parameters within the controller for maximum flows,” he notes. “For example, if you don’t want the flow in that main line to exceed 100 gallons per minute, you can set that parameter within the controller. You can measure flows through the controller; it automatically learns each station” as it test runs for a couple of minutes. “If that flow for that particular valve exceeds that set point, it will turn off that valve and that valve only. It could be a broken head or a broken line, but it will turn that valve off until you clear the controller, which means you’ve gone out and investigated it and effected the repair. Then you can re-energize the system and clear the alarm and it goes back to standard operating procedure. That gives us a lot of protection and a lot of capability onsite; it saves a ton of water and a ton of property damage.”
The combination of Moulton Niguel Water District’s smart controllers and online monitoring capability is reducing the district’s water usage, Blythe claims. “I’d say it has saved us about 25%-plus,” he says. “The water saved by this system turning the controller off when there are problems goes into hundreds of thousands of gallons.”
Managing Special Conditions
Karen Guz, director of the San Antonio Water System (SAWS) Conservation Department, faces some unique and amplified challenges as a result of managing two sites with the aid of online system monitoring capability. These include drought-necessitated watering restrictions, the need to reuse onsite recycled water in numerous irrigation zones, highly variable local weather, and SAWS’s public image in setting an example for water conservation.
SAWS owns two buildings, including a main building on a large campus purchased from an energy company in 2005. This 300,000-square-foot building features a system designed to reclaim water from the air-conditioning system and store it in large holding tanks. SAWS is using this water for the entire irrigation of more than 30 landscape zones on the property while in the midst of a two-year drought.
San Antonio residents have been restricted to outside watering via the city aquifer to one day per week throughout the year on an alternating, address-based basis. For its part, SAWS has been able to conserve water by alternately irrigating the numerous zones on its main building’s property using a combination of the reclaimed water, perched groundwater, and stormwater from the property every two days.
“We had so much water in our aquifer the first summer that we didn’t have restrictions, and then this last summer, we went into restrictions and we still haven’t come out, unless they have some rain,” says Guz. “We’re heading into our second summer of restrictions; there might be more restrictions than last summer. Our rules are designed to get everybody to cut back and they’re designed to reduce outdoor watering.”
The restrictions are requiring the district to sacrifice much more on its own building sites than residents do, says Guz. “If you’re a homeowner, you can easily water an acre too much during that watering window. Our campus is big enough that we can’t water to 100% of ET on one day between 10:00 a.m. and 8:00 p.m. We can manage, but we can’t keep everything lush on that allocation of time to water.”
The best way to conserve water and make use of the recycled water on the site is to rotate irrigation of the 30-plus zones roughly in groups of 10. SAWS is using smart controllers and ETwater Manager—a subscription-based online monitoring service from ETwater LLC—to keep track of all of these zones and so many irrigation variables. The utility enters its landscape variables on a computer screen, and the service provider collects climatologic data from a weather station located near the buildings and continuously adjusts the irrigation schedule for each zone accordingly. Guz particularly likes being able to manage so many variables from one location. “So far, it’s been working pretty well for us,” she says. “It’s awfully nice because it is more intuitive to most people to see a table with all of their zones and a little description of the landscape, what it is, and the location. You can open up the screen and you can see that Zone 1 is full sun and grass and the slope is whatever. You can open that and see that all at a glance instead of standing there with, hopefully, an as-built zone map and toggling though zone by zone.”
The drought and resulting water restrictions do result in some extra programming, Guz adds. “Watering to ET is reasonable in San Antonio; if everybody did that, we’re OK,” she says. “We normally would [water to ET] and we normally would ask everyone to water to ET, but we’re going to a bit of deficit irrigation to try to set a good example.” Guz customizes irrigation time per zone based on the address rotation or, in the case of the building property irrigated with recycled water, grouping the zones. When a zone is programmed for deficit irrigation, the system alerts Guz that the watering time is below ET replenishment level and requires a confirmation. “It’ll do what I want; it won’t override me, but I can override it,” she says.
One variable that a “smart” irrigation system must account for in maintaining an appropriate irrigation schedule is crop coefficient in a given zone. Crop coefficient essentially means a plant’s own ET variability. SAWS’s system does account for local crop coefficients that, Guz points out, are largely allowing the San Antonio area to withstand the drought. “The idea is that we put in the basic parameters,” says Guz.
“Once I agree that that [crop coefficient] assumption in their programming is one that I agree with, then all I have to do is tell the controller this zone is established shrubs and I tell it the slope. The controller should be smart enough to set the cycle and soak mode so we don’t have runoff and automatically, based on real-time weather, adjust up or down. So it’s built in so that when it waters, it’s going to turn on and off enough times that we don’t have runoff, and we just got rain, so it’s not going to need to be watered for whatever length of time—that’s got to automatically happen if it’s going to be a product that I’m going to be happy with in the long run. I would say to the consumer, ‘You’ve got to ask all of these things; don’t assume what the thing called the smart controller does or doesn’t do—ask.’
“The other thing that people want to ask is, what are the assumptions in this controller about those crop coefficients?” Guz continues. “In California, maybe trees have a crop coefficient of 0.8; appropriate trees for Texas wouldn’t live here if they had a higher crop coefficient than grass—they have a 0.3 or lower crop coefficient. The other question people might ask is, how do I deal with a highly stressful situation like trees that are growing on a parking lot island on 6 inches of soil surrounded by asphalt? Don’t assume that the smart controller knows that; you might have to program for that. You’ve got to be able to factor in all of those things.”
It seems as though Guz could not imagine managing all of these variables without the ability to view the status of each zone from the central location of a computer screen. “We’d be going outside a lot; every time there was a problem, someone would have to go downstairs, walk out there, look at the controller, toggle through to the zone, and change the setting,” she says.
Besides needing the ability to adjust settings for drought conditions, Guz notes that weather in the San Antonio area is inherently more variable during the spring and fall, which makes the real-time data that are available through her smart system particularly valuable. “We know summer’s going to be hot,” she says. “The rainfall is variable here all the time and in the spring and fall, we can have 90-degree-plus days continue into October, or October can be in the 70s. Same with the spring: On the first day of spring, we can have a 90-plus day where it’s incredibly hot, or it can be lovely and in the 70s.
“In order to get the full benefit of a smart controller, we need something that uses what’s going on right now, one way or the other, whether it’s soil moisture, whether it’s a full weather station or partial weather monitoring. To cut back when it’s cooler and wetter, we need it to be watching what’s happening right now and not what it’s historically doing in March or October.”
Yet another reason why online monitoring of the SAWS property irrigation is practically essential is that the utility must maintain a good public image regarding its own environmental stewardship in an area where water conservation is paramount.
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“I can’t afford to ever violate our own rules,” Guz says. “We absolutely cannot be hypocrites, so if I hear that there’s a breakup in the front area or something, I need to immediately go online and shut that zone off. What we’re trying to do is fairly complex. Between trying to follow our rules—and that means we can only water between 10:00 a.m. and 8:00 p.m., and that’s a hard and fast rule—again, heaven forbid we at the water company would break our own rules.”
Smart irrigation and online monitoring is not only helping SAWS avoid breaking its own rules—Guz estimates that these powerful tools are saving the utility 200,000 gallons of water from the city aquifer a month, or 2.4 million gallons a year, on its own properties.
May-June 2007
Complexity Control
As water conservation managers strive to optimize irrigation scheduling, online system monitoring helps them manage increases in variables.
Achieving optimal irrigation efficiency in commercial applications is not a matter of simply implementing new technology. Two water conservation managers who recently discussed their use of optimization-enabling technologies with
Water Efficiency indicated that high-tech tools do not replace sound management practices.
Scheduling irrigation according to evapotranspiration (ET) rate—the rate at which water is transferred from the earth to the atmosphere by combined evaporation of water and transpiration from plants—is becoming an increasingly common practice, and technology providers are making increasingly powerful tools available for this task. Foremost among these tools is the smart controller, which processes historical or real-time weather data variables and activates irrigation systems at the local level based on these data.
To the old axiom that information is power, however, one might add the corollary that a manager’s failure to process information variables can have a counterproductive effect. What is needed is a management tool to best manage information. An example of this is online monitoring of smart irrigation tools. This service allows water conservation managers to address operational exceptions and tweak irrigation schedules according to localized variables from one central location.
Labor Productivity Gets a Boost
Dave Blythe, recycled water coordinator with Moulton Niguel Water District in Orange County, CA, is concerned about conserving as much recycled water as possible. Local recycled water rules and regulations mandate the minimization of ponding and runoff. About four years ago, the district began utilizing Rain Master RME Eagle ET-capable controllers to help prevent waste on the roughly 80 properties that it owns and maintains. The controllers detect malfunctions in the field such as a broken head or pipe.
In 2005, the district added a significant amount of intelligence to its irrigation system by effectively networking the controllers using an iCentral control system from the same company. In the event of a malfunction in the field, the system sends a text message to Blythe’s cell phone and computer, as well as to those of his landscaping contractor.
In addition to handling these more catastrophic situations, the system helps Blythe regularly optimize recycled water use by making use of historical ET data. He could manually input these data for each controller from his computer but chooses to download the data, which are compiled on a zip code–by–zip code basis and use daily averages covering the past 30 years, from the hosted service’s Web site. In a district with varying terrain and climate like Blythe’s, these data are both powerful and beneficial.
“It’s based on zip codes and it seems to reflect the numbers that we would find throughout our district,” he says. “It’s a good happy medium to use because we’re in coastal hills, so we have a lot of microclimates. It can be foggy and drizzly toward the coast and it can be 60 degrees, and on the other side of the district, it can be 85 degrees and sunny all day—the data tend to reflect that very well.”
Blythe hopes to leverage even more powerful data by incorporating the latest weather conditions into the system starting next year. By installing the same company’s onsite weather stations near the controllers, the district will have the ability to replace historical data with real-time wind, rain, temperature, solar radiation, relative humidity, and ET data from each site.
As it is, Blythe says that the system helps him manage daily weather variables from one location and makes his manpower significantly more productive. “What I find from our landscape maintenance crews is that if they’re out working in an area, let’s say yesterday afternoon, and something goes wrong at about 3:00 in the afternoon—they’re normally off about 3:30—the supervisor gets a notification that there’s a problem somewhere,” Blythe says. “He can go over or have his crew go over before the end of the day, evaluate the situation, see what we’ve got, and if they have to stay late they can take care of the problem. Or, if it’s not a problem, it can wait until the next day—it saves them a ton of driving time, which means it’s going to get looked at immediately instead of 24 hours later.”
Also, management of Moulton Niguel Water District’s entire irrigation system makes more productive use of labor since the online monitoring capability was added. Blythe can make adjustments on all of Moulton Niguel’s controllers on any computer with Internet access after he enters a username and password. “Without iCentral, you’d have to do that out in the field,” he says. “The same with the alarms; the alarms would be stored with the controller in the field. With iCentral, we get them automatically.”
Blythe recalls when computer monitoring of controllers was available but not as flexible as it is today because the public did not have access to the Internet. “Now, a lot of manufacturers are heading this way and finding ways to give you more tools in the field, and from different computers,” he says. “It doesn’t have to be that dedicated computer—you can get onto the system at a Starbucks in San Francisco. I cannot physically visit each and every site every day. This helps me stay on top of the irrigation portion of things and reduces the call portion of the job. I still have to visit sites to do coverage tests and test plant materials, but this takes a big burden off.”
When it comes to making current weather-based adjustments to a system designed to operate based on historical data, the district yields greater water savings and labor productivity not just once but twice. “Let’s say we get into spring and it’s starting to warm up,” Blythe says. “The controllers are all on and they’re ready to irrigate. If we get a minor rain event, to get the [landscaping] contractor out there to change the settings or turn them off realistically isn’t going to happen at all 80 sites. And then to have them go back there and turn them back on [is challenging], whereas both he and I can do it from our desk or look at the weather report in the morning and say, ‘We really are going to get some moisture and let’s just go ahead and turn the system off.’ That’s a five-minute task, whereas it would take us all day to do it manually and then we’d have to go back out and do the same thing.”
Online monitoring capability is augmenting Blythe’s ability to troubleshoot system problems with the same manufacturer’s RME Eagle controller, which the district began using about five years ago. In addition to robust scheduling and ET features, one of the controller’s most useful tools is flow monitoring. Mindful that a malfunction sometimes occurs in obscure locations and can continue for days over a holiday weekend, Blythe cites the advantage of flow monitoring as a systemwide troubleshooting tool.
“We can set parameters within the controller for maximum flows,” he notes. “For example, if you don’t want the flow in that main line to exceed 100 gallons per minute, you can set that parameter within the controller. You can measure flows through the controller; it automatically learns each station” as it test runs for a couple of minutes. “If that flow for that particular valve exceeds that set point, it will turn off that valve and that valve only. It could be a broken head or a broken line, but it will turn that valve off until you clear the controller, which means you’ve gone out and investigated it and effected the repair. Then you can re-energize the system and clear the alarm and it goes back to standard operating procedure. That gives us a lot of protection and a lot of capability onsite; it saves a ton of water and a ton of property damage.”
The combination of Moulton Niguel Water District’s smart controllers and online monitoring capability is reducing the district’s water usage, Blythe claims. “I’d say it has saved us about 25%-plus,” he says. “The water saved by this system turning the controller off when there are problems goes into hundreds of thousands of gallons.”
Managing Special Conditions
Karen Guz, director of the San Antonio Water System (SAWS) Conservation Department, faces some unique and amplified challenges as a result of managing two sites with the aid of online system monitoring capability. These include drought-necessitated watering restrictions, the need to reuse onsite recycled water in numerous irrigation zones, highly variable local weather, and SAWS’s public image in setting an example for water conservation.
SAWS owns two buildings, including a main building on a large campus purchased from an energy company in 2005. This 300,000-square-foot building features a system designed to reclaim water from the air-conditioning system and store it in large holding tanks. SAWS is using this water for the entire irrigation of more than 30 landscape zones on the property while in the midst of a two-year drought.
San Antonio residents have been restricted to outside watering via the city aquifer to one day per week throughout the year on an alternating, address-based basis. For its part, SAWS has been able to conserve water by alternately irrigating the numerous zones on its main building’s property using a combination of the reclaimed water, perched groundwater, and stormwater from the property every two days.
“We had so much water in our aquifer the first summer that we didn’t have restrictions, and then this last summer, we went into restrictions and we still haven’t come out, unless they have some rain,” says Guz. “We’re heading into our second summer of restrictions; there might be more restrictions than last summer. Our rules are designed to get everybody to cut back and they’re designed to reduce outdoor watering.”
The restrictions are requiring the district to sacrifice much more on its own building sites than residents do, says Guz. “If you’re a homeowner, you can easily water an acre too much during that watering window. Our campus is big enough that we can’t water to 100% of ET on one day between 10:00 a.m. and 8:00 p.m. We can manage, but we can’t keep everything lush on that allocation of time to water.”
The best way to conserve water and make use of the recycled water on the site is to rotate irrigation of the 30-plus zones roughly in groups of 10. SAWS is using smart controllers and ETwater Manager—a subscription-based online monitoring service from ETwater LLC—to keep track of all of these zones and so many irrigation variables. The utility enters its landscape variables on a computer screen, and the service provider collects climatologic data from a weather station located near the buildings and continuously adjusts the irrigation schedule for each zone accordingly. Guz particularly likes being able to manage so many variables from one location. “So far, it’s been working pretty well for us,” she says. “It’s awfully nice because it is more intuitive to most people to see a table with all of their zones and a little description of the landscape, what it is, and the location. You can open up the screen and you can see that Zone 1 is full sun and grass and the slope is whatever. You can open that and see that all at a glance instead of standing there with, hopefully, an as-built zone map and toggling though zone by zone.”
The drought and resulting water restrictions do result in some extra programming, Guz adds. “Watering to ET is reasonable in San Antonio; if everybody did that, we’re OK,” she says. “We normally would [water to ET] and we normally would ask everyone to water to ET, but we’re going to a bit of deficit irrigation to try to set a good example.” Guz customizes irrigation time per zone based on the address rotation or, in the case of the building property irrigated with recycled water, grouping the zones. When a zone is programmed for deficit irrigation, the system alerts Guz that the watering time is below ET replenishment level and requires a confirmation. “It’ll do what I want; it won’t override me, but I can override it,” she says.
One variable that a “smart” irrigation system must account for in maintaining an appropriate irrigation schedule is crop coefficient in a given zone. Crop coefficient essentially means a plant’s own ET variability. SAWS’s system does account for local crop coefficients that, Guz points out, are largely allowing the San Antonio area to withstand the drought. “The idea is that we put in the basic parameters,” says Guz.
“Once I agree that that [crop coefficient] assumption in their programming is one that I agree with, then all I have to do is tell the controller this zone is established shrubs and I tell it the slope. The controller should be smart enough to set the cycle and soak mode so we don’t have runoff and automatically, based on real-time weather, adjust up or down. So it’s built in so that when it waters, it’s going to turn on and off enough times that we don’t have runoff, and we just got rain, so it’s not going to need to be watered for whatever length of time—that’s got to automatically happen if it’s going to be a product that I’m going to be happy with in the long run. I would say to the consumer, ‘You’ve got to ask all of these things; don’t assume what the thing called the smart controller does or doesn’t do—ask.’
“The other thing that people want to ask is, what are the assumptions in this controller about those crop coefficients?” Guz continues. “In California, maybe trees have a crop coefficient of 0.8; appropriate trees for Texas wouldn’t live here if they had a higher crop coefficient than grass—they have a 0.3 or lower crop coefficient. The other question people might ask is, how do I deal with a highly stressful situation like trees that are growing on a parking lot island on 6 inches of soil surrounded by asphalt? Don’t assume that the smart controller knows that; you might have to program for that. You’ve got to be able to factor in all of those things.”
It seems as though Guz could not imagine managing all of these variables without the ability to view the status of each zone from the central location of a computer screen. “We’d be going outside a lot; every time there was a problem, someone would have to go downstairs, walk out there, look at the controller, toggle through to the zone, and change the setting,” she says.
Besides needing the ability to adjust settings for drought conditions, Guz notes that weather in the San Antonio area is inherently more variable during the spring and fall, which makes the real-time data that are available through her smart system particularly valuable. “We know summer’s going to be hot,” she says. “The rainfall is variable here all the time and in the spring and fall, we can have 90-degree-plus days continue into October, or October can be in the 70s. Same with the spring: On the first day of spring, we can have a 90-plus day where it’s incredibly hot, or it can be lovely and in the 70s.
“In order to get the full benefit of a smart controller, we need something that uses what’s going on right now, one way or the other, whether it’s soil moisture, whether it’s a full weather station or partial weather monitoring. To cut back when it’s cooler and wetter, we need it to be watching what’s happening right now and not what it’s historically doing in March or October.”
Yet another reason why online monitoring of the SAWS property irrigation is practically essential is that the utility must maintain a good public image regarding its own environmental stewardship in an area where water conservation is paramount.
“I can’t afford to ever violate our own rules,” Guz says. “We absolutely cannot be hypocrites, so if I hear that there’s a breakup in the front area or something, I need to immediately go online and shut that zone off. What we’re trying to do is fairly complex. Between trying to follow our rules—and that means we can only water between 10:00 a.m. and 8:00 p.m., and that’s a hard and fast rule—again, heaven forbid we at the water company would break our own rules.”
Smart irrigation and online monitoring is not only helping SAWS avoid breaking its own rules—Guz estimates that these powerful tools are saving the utility 200,000 gallons of water from the city aquifer a month, or 2.4 million gallons a year, on its own properties.