Do you have time to water your entire green space by hand?
Few FMs can answer yes to that question, hence the prevalence of irrigation to maintain lush commercial landscapes. Irrigation accounts for about 30% of the average facility's water use, a number that rises even higher in drier regions, explains Stephanie Tanner, lead engineer for the EPA's WaterSense program.
Add in other outdoor uses of water and it's easy to see how this volume offers many opportunities to use water more efficiently. To get started, consider these five tips.
1) Stop Wasting Runoff Water
Make sure your existing equipment works correctly, notes Kurt Elvert, programs director for water use consultancy WaterWise Consulting. Wet pavement is a red flag that indicates your system may be providing too much water or spraying where it shouldn't.
"Water runoff is the No. 1 problem," Elvert explains. "Not only is water wasted, but it could lead to safety hazards as well because you're creating a slick hardscape."
Sprinklers that overspray onto sidewalks, parking lots, and streets are the most common, Elvert explains. Broken sprinkler heads and pipes will release more water than you intended. Runoff may also be caused by improperly installed equipment.
"With irrigation systems, the problem can be hidden, so you wouldn't know you have a problem," explains Amber Lefstead, WaterSense's outdoor coordinator. "Put a meter on your system and see if it's leaking. You could have a pretty big one but not notice it."
2) Consider Spray Alternatives
Looking to upgrade your irrigation system? A sprinkler system is easier to retrofit, but a drip system is more water-efficient because it delivers moisture to the roots of plants, notes Brian Vinchesi, principal of Irrigation Consulting.
Overhead irrigation, which utilizes above-ground sprays and sprinklers, is most common on larger lawns, but some of the water will evaporate, Vinchesi says.
The evaporation issue means drip irrigation is about 10-15% more efficient than a spray, but the two systems also differ greatly in construction and how easy they are to retrofit.
An overhead system doesn't require you to dig up the ground as you would for a subsurface drip system, and the visibility of sprays means you'll know right away if one of the fixtures isn't working.
Drip irrigation, which is commonly installed below the surface, is typically used for trees and planted beds but can be utilized for a whole lawn too. Above-ground drip systems can be installed for roughly 25 cents per square foot but are less common in commercial settings, Elvert says.
A subsurface drip system is easier to retrofit during a landscape project because the ground must be dug up anyway, allowing necessary trenching for the drip system without disturbing additional ground.
"You can run a drip system longer because you don't have to expose it to the sun and wastewater, but you don't know if anything is wrong until plants die," Vinchesi notes. "It's also more delicate – it's easier to put a shovel through it or damage it while putting in flowers." PageBreak
3) Fine-Tune Irrigation with Accessories
You may not need to replace your irrigation system if it's still in good condition. For a temporary solution with low input costs, consider using add-on devices to reduce outdoor water consumption.
Hoses: Shutoff valves allow you to cut off the water flow at the nozzle instead of at the water source. If you're using a hose or pressure washer to rinse hard surfaces, consider adding a water broom, Elvert recommends. The tool resembles a push broom, but instead of bristles, it has small water jets that aim water only where you need it.
Irrigation: A weather-based irrigation controller adjusts the timing of water depending on the previous day's weather and can cost $600 to $1,500, Vinchesi says. Some can also factor in evapotranspiration, a value combining the rates of evaporation and transpiration (how quickly the plant is absorbing water).
Look for a certification from the EPA's WaterSense program to ensure you're purchasing a water-efficient model, Tanner recommends.
"Compared to a simple clock timer, a WaterSense-certified controller can save you about 8,000 gallons per year," Tanner explains. "If everyone in the U.S. who has in-ground irrigation properly installed a certified irrigation controller, it would save about $435 million in water costs and 120 billion gallons of water annually."
Smart sensors: Areas vulnerable to periodic rain year-round, such as the Midwest, may benefit from rain sensors that shut off irrigation when they sense measurable rainfall, Lefstead says.
Soil moisture dispensers, on the other hand, keep the irrigation system off until they sense that the soil needs water. Pair them with the weather-based controller for best results, and if needed, look for a controller that will accept more than one sensor, Elvert adds.
4) Fix Your Fountains
There are several ways to reduce the amount of potable water needed to fill outdoor water features. Fountains, artificial waterfalls, and similar installations can use recirculated water or alternative water sources.
For example, the National Mall in Washington, DC, uses some potable water in addition to stormwater runoff from the ground. Rainwater catchment systems can also be a good match for water features, Vinchesi notes.
5) Look Closer at Water Use
To set benchmarks or figure out which fixture to tackle first, it might be helpful to request a water audit. Auditors typically take meter readings, measure the flow or flush rates of all water-using fixtures, and look for damage, then create a customized report on how to reduce your property's water usage.
For everyday maintenance, make sure you're using a professional who is WaterSense certified – the designation indicates a practitioner who is knowledgeable about water efficiency.
"Look at your occupancy. See who's there and what's being used and identify the areas where you'll get the most bang for your buck," Elvert says. "Any time of year is fine for an audit, but the late winter or early spring is ideal because it's before you can turn on your irrigation system, which increases water use. Make sure you're managing and operating it efficiently."
Janelle Penny [email protected] is associate editor of BUILDINGS.