Here’s a fun fact about water:Nothing on this planet lives without it; not plants, not animals, not bugs and certainly not us humans. We Homo sapiens can give up a lot of things — smoking, bacon burgers, gambling — but there’s no giving up water.
And the supply of water is something we just can’t take for granted anymore. All the experts say that clean, potable water is going to be in shorter supply in the future. We must find ways to use it more efficiently and recycle it as much as possible.
Clients of landscape and irrigation contractors often ask them for help in saving water. At the same time, clients also want their landscapes kept lush and green. The contractor must figure out just how much water can be cut without stressing the turf and the plants. In severe drought situations, this matter becomes much more serious.
There are many techniques and tools available to contractors to decrease water use without killing off every green thing in a landscape. Some of them you may already be using; others you may not have tried yet. Here are some of them.
Make sure you have good soil and mow high
For Mike Garcia, permaculture expert and landscape contractor and owner of Enviroscape LA, Redondo Beach, California, water conservation all starts with the soil. “If you have healthy soil, full of mycorrhizae and lots of good bugs like microbes and earthworms, you won’t need nearly as much water,” he says. If you’re putting a lot of synthetics or petroleum-based fertilizers on soil to make up for what it lacks, Wilson says you’ll only need a fraction of the water you’d normally use. If soil is deficient, adding compost or biochar will help build it up.
Just changing mowing height can save water, according to another permaculture expert, Bill Wilson, co-owner and lead teacher at Midwest Permaculture, Stelle, Illinois, a school that offers weeklong 72-hour intensives for landscape architects, contractors and anyone else who wants to learn about this approach to landscaping.
“If you use a variety of grass that looks good at 4 inches and keep it at that height, when it rains, less water runs off the property and more of it soaks in. Lawns become fresher and greener and require a lot less irrigation than if they’re kept at 2 inches.”
The water savings comes with an extra bonus: better soil. “Keeping grass longer builds a lawn’s topsoil and adds organic matter to it,” says Wilson. He says this happens even if you don’t mulch-mow, leaving the clippings in place — but if you do, even better.
Mulching also has a big role to play in saving water and protecting soil. “Putting down mulch serves a couple of different purposes,” says landscape designer Donna Dowson, owner of Dowson Design, Sacramento, California. “Besides making everything look clean, neat and finished, it protects the soil and helps reduce weeds. Bare soil loses a lot of water to evaporation, and mulch really slows that down.”
Her mulch of choice is wood chips. As they break down over time, they become organic material for the soil. And as Garcia also pointed out, the more organic your soil is, the more water it retains.
We can’t talk about saving water without mentioning permaculture, a growing movement within both landscaping and agriculture. While it includes aspects of organic landscaping, which eschews chemical inputs such as fertilizer, herbicides and pesticides, it goes way beyond that. Conservation of resources, especially water, is a big part of it.
What is permaculture? The definition differs slightly depending on which practitioner you talk to. “It’s seeing the world through the eyes of nature,” says permaculture expert and landscape contractor Mike Garcia, owner of Enviroscape LA, Redondo Beach, California. “It has three foundational principles: earth care, human care and future care, meaning that we leave the Earth a better place for our children.”
This is not just some West Coast trend. Bill and Becky Wilson own Midwest Permaculture in Stelle, Illinois, a school where landscape architects, contractors and all sorts of people from all over the country come to take weeklong 72-hour intensive training in the principles of permaculture.
“Permaculture is an umbrella word for all things sustainable; it’s shorthand for ‘permanent culture,’” explains Bill Wilson. “It’s looking at all the things we do and figuring out how we can do them in such a way that we can live a life that’s truly abundant.”
Techniques like soil conditioning, rainwater harvesting, turf replacement, digging rain gardens and planting natives are all permaculture practices. Growing edible landscapes is another big one.
Garcia mentions a recent visit he made to a client where he spotted a man’s big, healthy hydrangea plant. “Typically, those take a ton of water. I asked him how much he waters it, and he told me, ‘Almost never, it lives on rainwater.’ I said, ‘You’re kidding! You must be into permaculture.’ It turns out that he is, in a big way.”
As is Garcia. He believes so strongly in permaculture and water conservation that he filled in his own swimming pool and made a garden out of it. Of course, you don’t have to be as gung-ho as Garcia is to use some permaculture practices on the landscapes you tend. If you do, they’ll be better off for it.
Perform an irrigation audit
Doing a formal irrigation system performance audit, the procedure that involves laying out catch cans and doing mathematical calculations to determine a system’s distribution uniformity, will reveal a system’s inadequacies. One audit of a large condo development in Minnesota showed that out of the facility’s 7,800 total sprinkler heads, 28%, or 2,208 of them, were broken. When over a quarter of your sprinklers aren’t working right, it certainly can waste a lot of water, especially on such a large scale.
Although performing an irrigation system audit is invaluable, a simple irrigation inspection can also be revealing. You can pick up a lot of clues by simply turning on a system and walking the site scanning for obvious issues — things like clogged, broken or misting heads; wet walls and walkways; and water running into the street.
Change out old components and add new ones
You can dramatically decrease the amount of water used in a landscape by adding smart controllers and soil moisture and rain sensors.
You can also choose different components to deliver water through the system. Simply substituting more efficient Environmental Protection Agency WaterSense-rated nozzles for older or conventional sprays and rotors can cut water use by 30% or more.
Toro says its Precision series of nozzles can save 16,000 gallons of water per zone per year.
Rotary nozzles like Hunter’s MP Rotator and other similar rotary sprinklers made by different manufacturers deliver multiple, distinct streams of water. “The way a rotator works, with multiple streams of water coming out in bigger droplets, is all the water that comes out of it ends up on the landscape instead of in the air,” says Kelsey Jacquard, senior product manager, Hunter Industries, San Marcos, California. These sprinklers also have low precipitation rates.
All of the major sprinkler manufacturers have branded water-conservation nozzles. “In the industry, generally speaking, a water-conserving nozzle is one with a precipitation rate of 1 inch per hour or less,” says Chris Davey, product marketing manager, residential and commercial irrigation at The Toro Company’s irrigation division, Riverside, California. Some put down even less than that, one-half inch per hour.
Drip and low-volume microsprays and bubblers irrigate in terms of gallons per hour, where conventional sprays and rotors do it in gallons per minute. Drip and point-source irrigation deposits water directly to a plant’s roots, with little lost to evaporation. This type of irrigation is ideal for planter beds.
Use pressure-regulating sprinklers and check valves
If you’ve ever visited a county fair or a theme park on a hot day, you’ve probably seen the “misting stations” set up to keep visitors cool. But a sprinkler system that produces mist is just wasting water. “As pressure increases, so does an irrigation system’s flow rate,” says David L. White, channel marketing manager for Rain Bird, Azusa, California. “Visibly, high-pressure flows look like misted water and clouds of overspray that blow out of the irrigation zone with the wind. The results are wasted water, higher water bills and damaged system components.”
There’s a simple solution to this. “To get the largest amount of water savings with sprays and rotors, use the ones that are pressure-regulated,” says Davey.
In California, this will soon be a requirement. Starting next year, any new sprinkler nozzles sold in the state must, by law, incorporate pressure regulators. The Natural Resources Defense Council says that this alone could save over 400 million gallons of water per day in 10 years. Colorado, Hawaii, Vermont and Washington state have adopted similar regulations.
Davey says the second-largest savings would come from using some sort of a check device (also called a check valve), whether it’s an internal one built into the spray head itself or added on as an ancillary item. If it’s not already built into a nozzle, a check device can be threaded onto it. All the major manufacturers provide check device options in most of their pop-up spray or rotor lines.
Find turf’s happy medium
When a drought hits, municipalities and water purveyors start offering monetary incentives to home and business owners for replacing their lawns with artificial turf or plants such as succulents or natives.
Turf replacement is a controversial topic in landscape and irrigation circles, and understandably so. Landscape, landscape maintenance and lawn care contractors don’t like to hear people being encouraged to tear out grass lawns, as mowing, trimming, fertilizing, aerating and applying weed and pest control to that grass are their livelihood.
And grass has benefits. It produces oxygen, reduces soil erosion and reduces the urban heat island effect. Most of all, it produces beauty and provides human enjoyment and serenity.
The key is to find a happy medium, and that’s to water turf more efficiently. You can start doing this right away, without even changing out any of the sprinkler heads, by resetting the controller to “cycle and soak.” If the controller doesn’t have a cycle-and-soak setting, change the schedule so that the system stays on long enough to water down to a 6-inch depth. Then, the lawn should be allowed to dry out almost completely before the controller lets the system water again.
Deep, infrequent watering gets down to the grass’ roots and prevents saturation and runoff. Individual grass plants send roots deeper into the ground, resulting in healthier lawns — and a healthy lawn needs much less water overall.
Plant xeriscapes and natives
You can also exchange thirsty ornamentals for drought-tolerant plants such as cacti and succulents, plant natives, or use a combination of both.
Xeriscapes are popular in Arizona, and Andy Avots, co-owner of Agave Landscape, Gilbert, Arizona, installs plenty of them. Avots says xeriscape plants still need some water, just not as much. He cautions that every yard has a hot spot, and some plants, even xeriscape plants, can’t tolerate being planted there.
Planting natives is Avots’ choice when selecting water-saving plant alternatives. Natives need much less water because they’ve evolved in the region and are more likely to survive its conditions.
Recycle the rainwater
It is surprising that rainwater harvesting isn’t practiced more, since rain is one of the few things in life we get for free. And very few states have regulations controlling rainwater harvesting. If dollar bills or diamonds fell from the sky at regular intervals, everyone would have barrels out to catch them. It’s common in places like Africa, where rainfall isn’t taken for granted.
Interest in rainwater recapture systems peaks during periods of drought. During California’s last long dry spell, landscape and irrigation contractors who installed them had more work than they could handle. The market was driven by people’s fears of dead trees and landscapes in the face of draconian water restrictions and tiered rates. Now that the drought has been over for a while, the demand for these systems has cooled.
Systems range from a simple rain barrel or cistern that uses gravity to feed water into a drip irrigation system, to sophisticated setups with underground storage and filtration.
According to RainCatcher, a Tacoma, Washington-based nonprofit organization that works to provide clean water for children in the developing world through affordable and sustainable solutions, a 1,000-square-foot roof can capture as many as 625 gallons of clean water for every inch of rainfall.
Dig a rain garden
A rain garden is a bowl-shaped depression designed to collect runoff from a lawn, a roof or pavement and hold it temporarily until it percolates back down into the ground, keeping it out of storm drains. A rain garden can hold 200 gallons of water.
Wilson teaches his students how to construct them. They dig a 12-inch deep hole that is flat across the bottom with banked sides that slope about 45 degrees. “We put seeds and plant plugs in the bottom right away, and throw in some clover, as it pops up quickly and gives you a nice green look while all the other native plants and wildflowers are taking hold.”
Oftentimes, gravel is placed in the bottom to aid drainage. Wilson says that in the Midwest, it’s common to just have soil in the bottom of a rain garden; it depends on what type of soil an area has and how well it drains.
You’d think that a rain garden would be an ideal breeding spot for mosquitoes, but Wilson says it’s not. “When you first build one, water will sit in it for about three days; after a while, it’s lucky if it stays in there for one day. The breeding cycle of a mosquito is seven to 10 days. Unless it rains every three days or for 10 days straight, the larvae dry up.”
So, if we could design the ideal water-
efficient landscape, what would it look like? It would be irrigated completely or partially with collected rainwater, graywater or reclaimed water (partially treated sewage water is available in some places). Areas with grass would be fitted with precision spray nozzles or rotary sprinklers with matched precipitation rates; planting beds would have drip emitters, low-volume microsprays or bubblers. Then we’d add rain and soil moisture sensors and a smart controller to schedule everything.
On the landscaping side, we’d use a combination of native or drought-tolerant plantings, properly mulched, in good soil full of microbes and mycorrhizae with a rain garden or two thrown in.
Even if you do just one or two of these things for your clients, you will cut their water usage, and their bills, by a substantial amount. And they, and all the living things on this planet that can’t survive without water, will thank you for doing so.
The author is senior editor of Irrigation & Green Industry and can be reached at firstname.lastname@example.org.
The graywater that can keep landscapes green
It’s shocking to realize this, but every time we take a shower, wash our hands or launder our clothes, we’re wasting water — unless we’re recycling it back to a landscape somehow.
This wastewater, the effluent from bathroom sinks, tubs and clothes-washing machines, is called graywater. Some states classify kitchen sink discharge as graywater. Other states, because of its bacterial content, consider it “blackwater” along with toilet output and ban its reuse.
According the Water – Use It Wisely campaign, an Arizona water conservation effort, the installation of a graywater system can save a typical household around 40,000 gallons of water a year.
The easiest route is to build a simple laundry-to-landscape system. Plans for these are readily available on the internet, from nonprofit organizations like Greywater Action and others. More sophisticated systems are also available commercially; these would have a higher profit margin for an installing contractor.
Before you install anything, though, check your state and local laws to see what’s allowed in your area. Greywater Action began life as an underground effort, as recycling graywater was illegal in many states when they started promoting it.
There are some general rules that apply as well. Unlike rainwater, graywater can’t be stored longer than 24 hours because the organic matter in it decomposes and uses up the dissolved oxygen, making it smell bad among other things.
Because of what it contains, graywater can’t be channeled through conventional sprinkler systems; health authorities quite wisely don’t want the bacteria or viruses in graywater misting into the air. A properly filtered drip irrigation system is the main method for distributing gray-
water to landscapes.
Graywater comes with another plus for landscape plants and turf. The organic matter in it provides a kind of fertigation.