An alternative to irrigating with potable water
|Photos by Robert Rivera with Aqua Irrigation Systems.|
|Aqua Irrigation Systems installed three Norwesco 1,700-gallon cistern tanks using supplied lifting lugs. The Atlantahomeowners wanted a rainwater harvesting system that could connect to their existing irrigation, says Dan Young,vice president of Aqua Irrigation Systems. After making the connection, workers converted the system to a highlyefficient one using drip irrigation on all the homeowners’ plant material and using sprays on the turf.|
Dan Young is an entrepreneur who recognizes opportunity. As vice president and a partner in Aqua Irrigation Systems, Inc. (www.aquairrigation.org) in Marietta, Ga., Young saw the growing demand for water use to irrigate yards and gardens. “Under the current watering restrictions, you cannot irrigate with a conventional irrigation system using domestic potable water,” he says. “You must have an alternative source.”
Developing an approach
Young researched the use of capturing rainwater, and with the help of various manufacturers of rainwater harvesting products, he and his colleagues came up with a comprehensive approach and design.
Aqua Irrigation Systems, owned primarily by Russell Gold, uses a patented vortex filter to clean the water before introducing it into a cistern or aboveground tank. The system, known as a first-flush device, removes all the larger debris that would enter into a storage vessel, and in addition, oxygenates the water; any finer debris that may enter into the vessel becomes an aerobic layer enzyme that eats bacteria that may be present. A floating filter inside the vessel pumps from the water surface, so it is always using the cleanest water.
“It’s the most responsible way to irrigate, as this is a soft water without all the chlorination, fluorination, etc., found in potable water,” Young says. The system also helps to reduce nonpoint sources of pollution.
Challenges and benefits
Rainwater harvesting isn’t without its drawbacks. Young sees the biggest challenge as cost-effectiveness. “It is rare that a rainwater system will pay for itself in direct cost savings versus buying water, due to the low cost of water,” he says. “However, when there is no water to be purchased its value escalates.”
Whether the benefits of collecting rainwater offset the setup cost depends on the particular site and its demand for water, says Adrienne LaBranche Tucker,
irrigation consultant with Rainwater Management Solutions (www.rainwatermanagement.com) in Salem, Va. When deciding whether to install a rainwater system, she advises that landscapers and irrigation specialists first look at the customer’s supply and demand balance. The demand is the amount of water used, and the supply is how the need for water is fulfilled. Questions to ask include: Can the client rely on that water supply in the future? Is dry weather draining that resource? Will it be available in the future?
Figure out the system to meet your demand, Tucker advises, and keep in mind that what works best for each homeowner will be different. “Unfortunately, it’s not one plug-in-play type of system,” she says. “It really does have to be custom-designed for the site.”
In addition, you must determine the feasibility of installing a rainwater system and calculate whether the environmental payoffs will have benefits in the short and long term.
Young says convincing a client that bigger is better when it comes to water storage size can be a challenge. “Using a rain barrel is great, but you can only get so much water from a rain barrel,” he says.
Tucker agrees. “You can do a lot more with a larger storage system because you will still have several other downspouts that may be running off causing stormwater runoff; whereas, if you collected all of your downspout areas, then you really are having much more of an impact and collecting more water for your plant needs.”
That is another advantage to installing rainwater systems—it prevents stormwater runoff.
“It’s reducing stormwater runoff on-site,” she says, “so you’re really being more environmentally friendly by collecting that water.”
For most residential sites of about a quarter of an acre, Rainwater Management Solutions has installed 1,700 to 5,000-gallon tanks.
Tucker cautions that a 1-acre lawn requires a lot more water; she says 27,154 gallons of water is needed to apply 1 inch of water over 1 acre. “Normally, we try to tell people to scale it down a little bit and do more drought-tolerant plants rather than irrigating that whole area, because your collection tank will be significant,” she says.
An inground irrigation unit will need more storage capacity and a more sophisticated system with a pump big enough to meet the irrigation demand, Tucker says.
A smaller challenge Aqua Irrigation Systems faces is determining the correct elevations from the downspouts to the cistern. Young says all the piping must gravity-feed into the tank. If it doesn’t, the installer must improvise with a series of pumps that pump from one tank to another, then into the irrigation system.
|Workers with Aqua Irrigation Systems dig a hole before installing cistern tanks at anAtlanta, Ga., home, and level the ground using a laser level.|
Making the sale
When talking to a client about rainwater harvesting, Aqua Irrigation Systems dispatches a salesman to review the property and meet with the client to determine his needs and budget. “Then, we come up with a design and cost estimate,” Young says. “Depending on the site conditions, the actual cost may differ as there are circumstances that are unknown until you start to excavate.”
Tamim Younos, associate director of the Virginia Water Resources Research Center (www.vwrrc.vt.edu) on the campus of Virginia Tech in Blacksburg, Va., suggests that the benefit of capturing rooftop water, and collecting and storing it in underground or aboveground storage tanks, is great. He says during persistent and prolonged droughts, a rainwater system can switch back to public water supplies or well water.
He adds that the investment can help eliminate paying more for water supplies as costs increase. “An indirect advantage would be energy savings. Conventional and centralized systems, particularly pipe and pump-water distribution, are energy-intensive,” Younos says. “Our limited research shows that rainwater harvesting systems use less energy in the long term.”
Tucker recommends that landscapers add rainwater harvesting to their mix of services, saying people like the system because it frees them up from the water restrictions they may be under. If they are collecting their own rainwater on-site, homeowners are not utilizing the city’s potable water supply when municipalities are looking to protect that potable water source for drinking water.
In most cases, Rainwater Management Solutions recommends a municipal water source or well water as a backup system to the rainwater collection, which is especially important if a drought occurs and not enough rainwater is collected.
|Rainwater Management Solutionsprovided this 10,000-gallon abovegroundstorage system in Salem, Va. The water iscollected from a residential indoor tenniscourt and is used for landscape irrigationand pool refilling.|
This technique of collecting water is gaining popularity in America. “The research behind it in the United States is still trying to catch up to the demand for rainwater,” Tucker says. “We have a lot of landscapers who are looking to get more into the rainwater business because they go hand-in-hand. You’ll have a water supply on-site and can use that water supply for promoting plant growth.”
Currently, she says no national regulation standards exist in the United States for rainwater harvesting, but acknowledges that a few localities may have established some regulations concerning rainwater harvesting for irrigation.
As the demand for water grows, landscapers and irrigation specialists such as Young have noticed the importance of offering options to clients. “Offering rainwater systems was a natural addition to our range of services to increase our customer base as well as increase the satisfaction of our existing customers,” he says. “We feel that it sets us apart from the average contractor by offering various related specialized services.”
Established in 1988, Aqua Irrigation Systems primarily installs landscape irrigation systems, but has expanded its services to include low-voltage lighting systems, architectural fountains, pumping stations and rainwater harvesting.
Based in Danville, Va., Rocky Womack has written about agriculture and business for more than 25 years and currently serves as a contributing writer and correspondent for agriculture and business magazines, domestically and internationally. He has won numerous awards for his interviewing, writing and in-depth reporting.