By Dan Gregg
The economics behind water conservation are pushing cities to rely on architects and other landscape industry professionals to design spaces that are more energy efficient than ever before, to save not only natural resources, but also financial resources.
Against the backdrop of megadrought conditions in the Southwest United States, water management has become a priority for businesses — with even greater pressure in the landscape industry to reduce water use. With advanced technologies, heightened attention to design detail, further research into horticulture and a focus on education, professionals in the industry have more technology than ever before to create spaces that reduce water use, yet still are aesthetically pleasing.
Landscape architects are designing their projects to conserve water by using the topography of the land to create specific areas where water can be drained and then reused. Additionally, architects are sensitive to the types of plants and grasses that are used, ensuring those that require more water be kept to defined areas, so others are not over or underwatered in the process.
In geographies that lend themselves to hilly terrains, architects are using low areas to capture water. The water is then routed to waterbeds, which lets the plants wick water from underneath as needed. In the past, these beds were situated at the tops of hills and would strictly collect rainwater and not the runoff that is captured at the bottom of the hills.
Understanding the landscape and the uses for the space are key to creating an efficient plan. If the landscape space receives a lot of foot traffic, the design may have to account for more water to be used there. Previously, an architect would design landscapes for different activities, but it is now no longer just the function, but also the water used in the activities that are important considerations. The more foot traffic in a particular zone, like in areas of high activity, the greater the possibility of higher water uses. The focus on these areas has led to a better use of water in landscape design.
Using surface area runoff when excess water from rain flows over the land is a way to save energy and money for businesses that desire to keep water onsite. It’s becoming more common to install underground tanks to collect water and pump it out through the irrigation system. But where does that water come from?
One design tactic that is appearing more frequently is the use of permeable surfaces in spaces such as parking lots where grass grows both around and throughout the concrete surface in a grid pattern. This grid pattern enables water to seep in, collect and be reused instead of being diverted into storm drains, over burdening the drainage system.
Other areas where excess water gathers include the condensation of air conditioning units and the roof, which is the largest collector. Water collection from the roof is a growing practice among those seeking to be more water-conscious, though this is normally seen in commercial buildings rather than residential.
The technique of rainwater harvesting continues to grow in popularity, both for residential and commercial properties. The rainwater harvesting system collects rain from the roof or other nonpermeable surfaces in basins or tanks and recycles it for irrigation and other applications. Homeowners and businesses using this technique save money by avoiding the need to buy water from a municipality, and also contribute to water preservation efforts.
Rainwater harvesting is particularly useful in areas where there are restrictions on lawn watering. In these areas, the rainwater can be pumped through a hose or irrigation system and used on the landscape. The system usually follows an easy retrofit process, making it a simple solution for those seeking water-saving alternatives.
During the past 30 years irrigation technology has improved greatly, with the largest advancements in controllers. Older electro-mechanical units had no program flexibility, but newer digital units are highly customizable to meet any variety of water needs or fit local water conservation guidelines and personalized landscape designs.
Today’s controllers enable the user to separate certain areas of the landscape, like beds and turf, and use different watering levels for each. This ensures that each area remains watered to optimal levels, while conserving where possible. Larger, more advanced systems even use satellite weather data to provide the user with daily evapo-transpiration values to better manage water use.
Pump stations have also evolved. New software programs manage power and efficiency better than ever before with the use of variable frequency drives (VFD). VFD technology enables the control of the AC motor speed and torque by varying the input frequency and voltage to match the system demands. As demand increases, the VFD speeds up to match the needs of the irrigation system, which helps control efficiency.
Throughout the Southwest U.S., there is an increased push to educate the public about water conservation needs. Some municipalities have water conservation programs to encourage residents to take part in the effort by using techniques like rainwater harvesting.
For example, Fort Worth, Texas, sells rain barrels to homeowners so they can collect water for applications such as watering the lawn or garden. The city has also launched a marketing campaign to encourage residents to conserve water.
Water conservation will continue to be a hot topic among landscape industry professionals for the foreseeable future. The market is poised for an increase in measurement tools, such as flow sensors and moisture sensors. Reverse osmosis system use is on the rise across the U.S. in order to utilize all water resources available.
Landscape architects will continue to design spaces that are not only functional, but also help conserve water. By encouraging the use of water management systems and informing customers of these methods, the U.S. can continue to curb its water usage, saving not only this diminishing resource, but also money.
Dan Gregg is the central regional sales manager for Flowtronex Prepackaged Pump Stations, a Xylem Applied Water Systems brand. He is a registered landscape architect, Texas Licensed Irrigator and EPA Water Sense partner with more than 35 years of experience in landscape irrigation design, consultation and sales.