By Bryce Carnehl
From the June 2023 Issue
Whether your clients’ water is sourced from a well, pond, municipal system, or rooftop, it’s crucial to understand the responsibility of managing such a valuable resource. We are more concerned than ever about protecting our water supplies and ensuring they are used for only the most necessary of purposes. So is irrigation necessary?
To answer this question, imagine what life would be like in a city without green spaces. What if there was no Central Park in NY, no National Mall in DC, no Golden Gate Park in San Francisco? Irrigation is an essential part of the green spaces in which we live, work, and play.
Recent years have seen reinvigorated interest in both public and private outdoor spaces. To maintain those green spaces in our urban environments requires supplemental rainwater in the form of irrigation. Our green spaces provide us tangible benefits such as shade to cool, and oxygen and fresh air to breathe. They also supply carbon sequestration and stormwater filtration. Designing, sustaining, and irrigating them properly can create a healthy landscape, with deep roots and a structure that is more resilient to drought conditions.
Landscape Irrigation: A Balancing Act
How do we balance this need for supporting our vital greenspaces with the need to preserve our most precious natural substance, fresh water? We must ensure that as irrigation professionals we are treating the responsibility of using a scarce natural resource to the highest effectiveness possible. Or, as my grandmother always said, waste not, want not.
With outdoor watering in the crosshairs, the ALCC provides clients a way to be part of the solution, not part of the problem. Read more…
Using alternative water resources is one option, but even those resources can be limited. Having an efficient irrigation system is one part of responsible water use and helps to create a more drought resilient landscape.
Here are several steps you can take to ensure the most responsible use of our sacred green spaces and fresh waters:
1. Conduct regular irrigation audits.
The most basic maintenance can help prevent catastrophic losses. Ensuring that leaks and clogs, overspray, runoff, or broken parts are repaired or replaced as soon as possible reduces potential plant losses, water waste, and extensive system damage. Auditing the irrigation system seasonally, or as appropriate for your area, can alert you to potential issues and identify opportunities for upgrading equipment to more efficient components.
2. Know the pressure.
It’s well known in our Industry that operating pressure must be just right. Too high and you experience misting, water drift, and damaged components; too low and you could be over-irrigating to compensate for poor performance, causing flooding and runoff. The use of pressure regulated spray bodies is now required in 13 states and more are on the way.
Carry a pressure gauge and learn how and when to check the pressure of client systems. It changes over time and should be part of seasonal maintenance. Check valves go hand in hand with pressure regulated spray bodies, but can be used in other places in the system to prevent low head drainage. Low head drainage is not only responsible for water waste, but can also damage the landscape, cause localized flooding issues, and exacerbate other hydraulic problems in a system.
3. Use MTMS nozzles.
Multi trajectory multi stream nozzles mimic gentle rainfall, operate at lower flows, and provide greater coverage than standard spray nozzles. They revolutionized the industry when introduced as MP Rotators twenty years ago, and continue to dominate the market in high performance overhead irrigation. With a range of matched precipitation nozzles, they can retrofit almost any application, and simplify the design of new projects.
4. Convert to micro irrigation.
As the popularity of lawns give way to other types of plant material, overhead irrigation is not always the ideal way to provide water where the plant needs it most. Using micro irrigation applies water directly to the soil. In the case of subsurface irrigation, water is applied directly to the roots. This reduces atmospheric losses of water. Massive water savings can be achieved, while simultaneously improving plant health, reducing weed pressure, and minimizing green waste.
5. Choose the right plants for the right place.
Obviously, growing papaya in Alaska, or blueberries in Arizona presents several challenges. While we may be willing to jump through hoops for food crops, we need more sustainable options for our green spaces. As many know, climate adapted plants require fewer inputs and accommodations. They have greater pest resistance, require less soil amendments, and generally survive local weather conditions. They also need less supplemental water.
6. Use hydrozones.
It’s not just about picking the right types of plants, as stated above, but also grouping them together by their needs. Avoid planting oaks in turfgrass, or ceanothus in a bog collection. By planting species together by water needs, or hydrozone, irrigation systems are better able to water just what is needed, where it is needed. Hydrozones eliminate over-irrigating drier plants to provide for thirsty plants.
7. Conform to local restrictions.
There are increasing regulations and restrictions on outdoor watering. Often, these can actually be healthy for a well-maintained landscape. For instance, watering during nighttime hours can help with disease resistance and reduce water loss to evaporation. Watering only a few days a week means deep and less frequent water cycles which encourages deep root growth and greater drought resistance in many plants. Many areas that have watering restrictions also have rebate programs to install efficient irrigation systems, so be sure to check with the local agency for available funding to incentivize clients.
8. Use the latest in controller technology.
Be smart and use smart controllers. The weather changes nearly every day along with the water requirements of a landscape, so should irrigation schedules. When paired with efficient irrigation application devices, smart controllers can help conserve a tremendous amount of water by adjusting irrigation schedules based on environmental data inputs. Cool, overcast, and damp; irrigate less. Warm, sunny, and dry; irrigate more.
Weather-based smart controllers use on-site sensors or data from nearby weather stations to modify irrigation schedules based on atmospheric conditions. Soil-based smart controllers employ sensors to measure soil-moisture content to modify schedules helping to ensure overwatering does not occur.
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Always consider including an on-site rain shut off device with any smart controller to ensure watering is not occurring when it is actually raining. In addition, flow sensors and flow management can detect system leaks, prevent catastrophic failures, and even create reports on water consumption. Combine these tools, grow your service offerings, and give your customers the confidence that their landscape irrigation is indeed smart.
Preserving Landscapes & Water
Remember, when irrigation is working perfectly, it’s invisible. We rarely look at a beautifully maintained and healthy landscape and reflect, “wow, what a great irrigation system.” In that sense, irrigation managers are the invisible heroes of the landscape industry, and with that comes great responsibility.
Managing a scarce resource to sustain landscapes, supporting biodiversity in built environments, and creating moments and memories for people in outdoor spaces is no small task. Use the tools mentioned here as they match your irrigation projects and site conditions, while understanding the needs of your customer. Take the opportunity to find the balance between supporting green spaces while preserving our most precious resource.
Carnehl, specification marketing manager with Hunter Industries, has been in the landscape industry for over 20 years working in construction, landscape architecture, sales, corporate social responsibility, and marketing. Throughout these years he has dedicated himself to promoting the value of green spaces. Every project begins with a plan, and better planning leads to project success. Carnehl now works to create business opportunities for landscape partners through design, planning, and specification efforts. He believes that together we can build business prosperity, increase the value of landscapes, and ensure healthy communities in which we all live, work, and play.
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