Experienced landscape irrigators share what works for them
Spring irrigation start-up is an ideal time to analyze a system for inefficiencies and to recommend repairs and upgrades to make irrigation more efficient.
Photo courtesy of Pacific Landscape Management.
With a greater awareness that water is a vital, non-renewable resource, water conservation has become increasingly important. Add to that the pressures of persistent drought conditions across much of the nation and escalating water costs. It’s no wonder irrigation professionals are recommending assessment of existing irrigation systems to determine if renovations can result in water and money savings for their clients.
Each geographic area and mix of clients brings its own unique challenges.
Reno Green Landscaping, Reno, Nev., works primarily with commercial accounts, with residential accounts are a small portion of their business.
“Our sites have a lot of turfgrass, from large open areas to those 6-foot-wide strips between sidewalks and streets,” says Mike Short, CLIA (certified landscape irrigation auditor). “Brown spots in the turf are not acceptable for our clients. That’s a prime consideration for whatever we do in system design or renovation.”
Reno is in a drought crisis, with a multi-year drought pattern and now the two driest winters on record.
Short says, “Water requirements in our area are almost as much as in the Phoenix high desert. Our elevation range is between 4,500 feet to 6,500 feet. Soil radiation is intense. Humidity levels are extremely low, around 10 percent, but often in the single digits, and we’re fairly windy. There’s a huge variation within our microclimates; we may have pouring rain at one site, not a drop at another. Temperature swings can be extreme, too, with freezing or close to it in early June then reaching record highs that last for several weeks.”
Corey Petersen, CLIA, is sustainability coordinator for Pacific Landscape Management, Hillsboro, Ore., which serves commercial clients with a mix of irrigation areas similar to Reno Greens.
“Despite the Northwest’s rainy reputation, our region is actually one of the driest in the country during the summer,” says Petersen.
Elliott Moore, owner of Moore’s Irrigation and Landscape Lighting, Omaha, Neb., says the company fills the role of irrigation services provider for some local full-service maintenance companies, as well as working directly with their own clients. Moore says, “Our client mix is mostly residential, with a wide range in property size and types of areas irrigated.”
Ryco Landscaping, a design/build and maintenance company in Lake of the Hills, Ill., offers “complete care” to residential and commercial clients, which includes design, installation and maintenance of irrigation systems.
Dana Voyles, CLT, serves as an account manager, with her own block of residential clients, as well as manager for the irrigation department. Voyles says, “Most of our irrigation clients are residential.”
These Midwestern regions are notorious for erratic climate, with brutal summers, wide temperature fluctuations, and flood to drought precipitation swings.
All these regional climatic challenges result in hefty water requirements for turfgrass, the top consumer of water.
The upgrade markets
“Many of our upgrades involve expansions to existing turf-only systems to cover plant beds when people get tired of dragging hoses. Those are basic, just adding a zone or zones,” says Voyles.
“More problematic are the renovations for those who have an existing system that hasn’t been operated for a year or more. Many people didn’t irrigate during last year’s drought, assuming the grass would go dormant and snap back in the fall. Much of it didn’t. So they started the spring with a major turf renovation and wanted their systems up and running to keep it going. If it isn’t one of our installations, we usually have no as-built data on it, so it’s like solving a puzzle just to uncover what’s in place and analyze its performance.”
A lot depends on the placement of the catch cans for a properly conducted irrigation audit. The higher the DU, the more efficient the irrigation.
Photos courtesy of Reno Green Landscaping, unless otherwise noted.
Moore adds, “We do a lot revamps. Some are 15- or 20-year-old systems that aren’t operating well. Others involve a re-landscape or a hardscape or swimming pool addition that makes the old system obsolete. Others focus on correcting inefficiencies.”
Petersen says, “We do offer a full audit service. More often the focus is on a specific trouble area. We go through a complete assessment of that segment of the system, including a pressure check at the heads and determine how best to raise the efficiency.”
“Smart controllers don’t fix dumb irrigation,” says Short. “The average system uniformity for any sprinkler system coast to coast is 48 percent. I’ve audited some that were into the 30 percent range. With any percentage lower than that, the client would generally be better served by replacing the system, rather than attempting to renovate it.”
A water audit pinpoints dry and wet spots on a landscape and provides a snapshot of distribution uniformity (DU) that can suggest system adjustments.
Correct problems first. Fix leaks, replace broken heads, reset sunken heads, straighten tilted sprinklers, reposition misaligned part circle spray heads, reset or replace with greater pop-up height for sprinklers blocked by vegetation. Resolve pressure problems.
Short says, “We’re still finding systems that mix spray heads with rotors on the same valve. There’s a huge difference in what each puts out in water over the same time period.” Rotors from different suppliers can also be mismatched, if the precipitation rates vary. “The nozzle trajectory needs to match, along with the gallons per minute (GPM) output and the rotation speed,” says Short.
Keep it Going
“One of the most important things is to have properly trained irrigation technicians that are subject to continual training,” says Mike Short, CLIA. “It’s a new age. Technicians need to evolve to a new level of technology. They’re the water managers, proactively monitoring the systems for maximum efficiency. By doing all this, we save water, save money and see huge improvements in our plant health and turf quality.”
“Probably the most important thing for us is educating our customers as to what the proper watering requirements are for the different plants and microclimates their system covers,” says Voyles. “Managing the irrigation systems on more and more of the properties gives us a greater opportunity to impact overall landscape maintenance.” It takes the synergy of right plant; right place to the next level by adding the critical element of right water.
Selling the service
For the majority of Ryco’s clients, the focus is on making the systems as consistent as they can be with the components they have. Voyles says, “If they have nozzles or a controller not functioning properly, obviously we talk to them about upgrades, explaining the potential savings of the higher tech options. To date, we don’t have any residential clients on a smart controller or any type of ET-based system.”
Moore says, “No one is calling us looking for an upgrade to save water. We bring up the issue to the client. With older systems, we’ll lay out approximately what it could save them, though we can do an anticipated ROI if they ask for it. We’re using a lot of Rain Bird’s smart controllers at the client’s site. The models vary depending on the individual system. We’re switching to Rain Bird’s PRS pop-up spray heads with pressure regulating stems in a lot of upgrades. About 30 percent will convert with the approximate savings. The others will opt to do it later, when the system is not working very well.”
A key part of the annual system start up is making sure everything is functioning well. Petersen says, “That’s an ideal point to analyze the most inefficient parts of the system and try to tackle them within the client’s budget. For commercial clients, absolutely everything is about ROI. We want solutions that give them the most bang for the buck. That may be replacing turf with a more workable alternative, changing out a zone or stepping up to a smart controller.”
The irrigation service and renovation section on Pacific Landscape Management’s website (http://www.pacscape.com) contains a link to a weather-based irrigation document that provides a good overview of what to expect with a weather-based smart controller.
The audit of this area will also consider the impact of the degree of slope, potential wind issues and varying sun and shade patterns on system efficiency.
“That generates a lot of interest,” says Petersen. “We have case studies that list the actual investment, savings and ROI to back that up. We’ve worked a lot with Rain Bird’s ET managers. The options vary depending on the size of the site. We’re averaging 20 to 40 percent savings and an ROI of less than two years.
“For a large property, we can measure the total square footage devoted to turf and landscape features and multiple that by the average water usage in gallons for standard controllers compared to smart controllers to give an estimate of potential savings. Obviously the exact savings will vary per site and per season, but that method has worked out really well for us.”
“I ask them for their water bills,” says Short. “It’s all about return on investment. If renovation will make their system 20 percent more efficient, we can cut their water bills by 20 percent. As water costs rise, the ROI period gets shorter. Conservatively, we estimate the average savings with a smart controller is between 10 and 30 percent without redoing the entire system. But we’ve seen results in the 40 percent range, occasionally even hitting 50 percent especially for older systems.”
All of these pros work with “any and all” irrigation systems but, as Petersen says, “We’re continually evaluating new introductions.”
Often a lawn will get varying amounts of sun and shade during a day. This must be taken into account in an audit.
One model ET controller Short uses is HydroPoint’s WeatherTRAK. “The real time, ET-based information is great. They monitor the system 24/7 and we get automatic alerts if there’s a problem,” he says. “Rain Bird has some stand-alone controllers with their own onsite weather sensing that we’re using on smaller commercial properties and residential sites with good results. These all have to be programmed properly and audited. Otherwise it’s just guess work.”
Short works with multiple nozzle options, too. “The Hunter MP rotators with the multiple streams are one of the most efficient.” Hunter also offers the MPR40, a spray body with a specially calibrated spray regulator for consistent 40 PSI output. “Rain Bird’s 5000 MPR single stream rotor system nozzles deliver matched precipitation rate,” says Short. “Toro’s Precision series spray nozzles also perform well for us.”
During an irrigation audit, the auditor collects data, verifies that systems are working as designed and identifies opportunities to improve water efficiency. It’s the most precise way to evaluate a system.
Short says, “The two most important factors are the net precipitation rate and the distribution uniformity (DU). The gross precipitation rate is what leaves the nozzle. The net precipitation rate is what actually makes it to the plant roots. It’s the net precipitation rate that the ET controllers need to know. The formal term, IA standard, is known as low quarter distribution uniformity. Twenty-five percent of the heads will have lower precipitation rates because the pressure is less, the spacing is greater, or site factors vary. We need to make sure the system covers that low quarter distribution uniformity.”
Once those two factors are known, Short says, “We determine the soil types, slopes and plant types so we can program that into a smart controller. Then we have wonderful results and it works like it’s supposed to. It still needs babysitting and some fine-tuning as we track the system operation. We also need to calculate the seasonal percentage adjustments.”
After the retrofit is completed, system performance must be monitored and presented to the client on a regular basis.
High-tech programs provide a reading of water use over a specific period. A spreadsheet layout can show monthly water use for two or three years prior to the renovation, along with total usage for each year. Some pros suggest including the monthly and totally annual averages for those years. The post-renovation data is then recorded in the same format for comparison, with the percentage of water savings listed for each month, and the total for the year.
Petersen and Short recommend monitoring in the years after the renovation to show the client those savings are continuing.
Suz Trusty is a partner with her husband, Steve, in Trusty & Associates, Council Bluffs, Iowa. She has been involved in the green industry for more than 40 years. Contact her at firstname.lastname@example.org.