By Dan Gregg
Nearly one in 10 watersheds in the United States is stressed with demand for clean water outweighing supply. According to a 2013 report by NOAA’s Cooperative Institute for Research in Environmental Sciences, this demand comes from the 313.9 million people living in the country and their needs, such as food, drink, cleaning, manufacturing and landscaping, to name a few.
With such pressure being put on water supply, businesses, governments and individuals must look for ways to curb water usage. Water conservation is as hot of a topic as ever due to this need to use resources efficiently, though it is also driven by economic factors.
Although water management should be a priority for most businesses, the landscape industry faces increased pressure to sustain water use. Fortunately, with advanced technologies, heightened attention to design detail, further research into horticulture and a focus on education, professionals in the industry are poised for success to contribute to water conservation.
The conversation surrounding water preservation generally focuses on the need for clean water supply for human consumption and use. That’s not the only reason this hot topic continues to be at the forefront. 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, while not only saving natural resources, but also financial resources.
While watersheds and other sources supply a limited amount of water, populations continue to grow, leading to two primary challenges for municipalities. First, fresh-water treatment facilities are beginning to top out, creating demand to build new plants. Second, cities must rid themselves of treated waste water, but can only let a limited amount into creeks and rivers. This leads to the need to strike a balance between how much to treat and how much to dispose.
Determining the amount of water to treat is at the core of both challenges. It is a delicate balance, since water is almost drinkable once it is treated, but only a certain amount per day is discharged. If too much is treated, then a city must dispose of it. If too little is treated, the city may need to build an additional facility. Of course, there are costs associated with the building, so methods for reusing water are explored before investing in additional infrastructure.
What does a city do if it has too much water? Some have started contracting with golf courses to install an effluent water supply pipe, so they can use the treated water to irrigate the golf course. The challenge here is that both sides must agree on how many gallons to use per day. If the golf course takes in too much water, it is wasted and the grass may be over watered, resulting in undesirable playing conditions on the course. Another challenge is the buildup of salts from the effluent water supply, which must be monitored very carefully.
Tools to manage water
Landscape architects have more tools, knowledge and technology than ever before to create spaces that reduce water usage, yet still are appealing to the eye.
Landscape architects are designing their projects to conserve water by using the lay of the land to create specific areas where water is drained and can then be reused. Additionally, architects are sensitive to the types of plants that are used, ensuring those that require more water be kept to a specific area, so others are not over watered in the process.
In geographies with hilly terrain, architects are using low areas to capture water. The water is then routed to waterbeds for reuse. In the past, these beds were situated at the top of hills and would strictly collect rainwater and not the runoff that is captured at the bottom of the hills.
Understanding the area and the uses for the space is key to creating an efficient plan. If the space receives a lot of foot traffic, the design might have to account for more water to be used there. In the past, an architect would design areas for specific activities, but it is now no longer just the function, but also the water used in the activity (the more activity in a particular zone, 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 or snow flows over the land, is a way to save energy and money for businesses, creating a need to keep water onsite. It is 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 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 where it overburdens the drainage system.
Other areas where excess water gathers include the condensation of air conditioning units and the roof, which is the largest collector. Although most of these methods are used in commercial buildings rather than residential, water collection from the roof is common for homes looking to be water conscious.
The technique of rainwater harvesting continues to grow in popularity, both in residential and commercial spaces. A rainwater harvesting system collects rain — from a roof or other non-permeable surface — 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 the city, and also contribute to water preservation efforts.
Rainwater harvesting is especially useful in areas of the country where there are restrictions to how frequently people can water their lawns. In these areas, 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 looking to conserve water.
During the past 30 years, irrigation technology has been enhanced greatly, with the largest improvement seen 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 municipalities’ water conservation guidelines. Today’s controllers enable the user to separate certain areas of the landscape, such as 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 (E.T.) values to better manage water use.
Pump stations have also evolved. The new software programs available 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 country, there is an increased push to educate the public about water conservation. Certain cities have started water conservation programs to encourage residents to take part in the effort by using techniques such as rainwater harvesting.
For example, for a reduced price, Fort Worth, Texas, provides homeowners a rain barrel they can use to collect water for applications such as watering lawns or gardens. The city also has enacted a marketing campaign to encourage residents to conserve water.
Water conservation will continue to be a hot topic among landscape industry professionals in 2014 and beyond. The market is poised for an increase in measurement tools, such as flow sensors and moisture sensors to better manage how much water is used. There will also be an increase in reverse osmosis (RO) systems for irrigation use. RO systems to remove salt are no longer only used on the coasts, but are now popping up inland due to salt appearing in lakes and streams in many places, such as western Texas.
Landscape architects can 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 United States can continue to curb its water usage — saving not only this resource, but also money.
Dan Gregg is the central regional sales manager of prepackaged pump stations for Flowtronex, a Xylem 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.