Water-Efficient Landscape Design - New Jersey Green Building Manual
GREEN BUILDING MANUAL NEW RESIDENTIAL UPDATED 2-MAY -11Water-Efficient Landscape DesignWhat is Water-Efficient Landscape Design?Water-efficient landscaping has many different terms associated with it but most rely on thesame basic principles. Xeriscape landscaping, for example, is defined as “quality landscapingthat conserves water and protects the environment.” Most water efficient landscaping approachesincorporate the following suggestions: 1 o Group plants according to their water needs o Use native and adapted plants (see Native and Adapted Plants strategy) o Limit turf areas to those needed for practical uses o Use efficient irrigation systems o Schedule irrigation wisely o Make sure soil is healthy o Remember to mulch o Provide regular maintenance Figure 1 - Non-Xeriscaping (left) and Xeriscaping (right) (Source: US EPA – Water-Efficient Landscaping)1 US EPA. Water-Efficient Landscaping: Preventing Pollution & Using Resources Wisely.http://www.epa.gov/watersense/docs/water-efficient_landscaping_508.pdf (accessed April 15, 2010). Denver Waterwelcomes the use of the term Xeriscape in books, articles, and speeches promoting water-conserving landscape.Rutgers Center for Green Building is using this term with permission from Denver Water. For permission to use“Xeriscape” in your publications, call Denver Water at 303 628-6330.
GREEN BUILDING MANUAL NEW RESIDENTIAL UPDATED 2-MAY -11Water-efficient landscaping reduces water consumption and protects water quality. The US EPAestimates that the average family of four uses about 400 gallons of water per day, 30 percent ofwhich is dedicated to outdoor use. Landscape irrigation accounts for more than one third of allresidential water use nationwide. Water use is dependent on location and climate but in someareas, up to 50 percent of water used to irrigate may be lost to evaporation, wind, and impropersystem design or overwatering. 2 Minimizing or eliminating the use of potable water for irrigationcan conserve clean water for the benefit of the environment and the community.How to Implement Water-Efficient LandscapesNatural rainfall is the best source of water for plants in the landscape and one way to conservewater is to design landscapes that need only natural rainfall to survive. These landscapesgenerally only require supplemental irrigation during the plants’ initial establishment period.Climate-based controllers for irrigation systems can also decrease water used for irrigation.Consider using non-potable water for irrigation (see Rain Barrels and Cisterns and On SiteGreywater Treatment strategies).3For more extensive information on water efficient landscaping, refer toUS EPA’s Water-Efficient Landscaping: Preventing Pollution & Using Resources WiselyVoluntary programs, like US EPA’s Greenscapes Alliance, help guide the implementation ofmore eco-friendly landscapes, including water efficient landscaping.BenefitsEconomic: o Lowers water bills – careful design and choice of appropriate plants can reduce outdoor water use by 20 to 50 percent 4 o Increases home values – attractive, water-efficient landscaping may increase property values o Saves money spent on landscape maintenance because many water-efficient plants require less care o Reduces tax burden because water resource infrastructure is less burdened2 US EPA. Outdoor Water Use in the United States. http://www.epa.gov/WaterSense/pubs/outdoor.html (accessedDecember 10, 2010).3 Sustainable Sites Initiative. Hydrology. http://www.sustainablesites.org/hydrology/ (accessed November 20, 2010).4 US EPA. Outdoor Water Use in the United States. http://www.epa.gov/WaterSense/pubs/outdoor.html (accessedOctober 20, 2010).
GREEN BUILDING MANUAL NEW RESIDENTIAL UPDATED 2-MAY -11Environmental: o Conserves natural resources o Protects habitat and biodiversity when existing habitats are preserved and/or new native plant communities introduced o Lowers energy use due to less pumping and treatment of water o Reduces stormwater and irrigation runoff that carry top soils and pollutants into waterwaysPersonal Wellness: o Saves time spent on landscapingCostsThe cost of water efficient landscaping does not exceed the cost of conventional landscaping.The cost and cost-savings of water efficient landscaping will vary depending on the local cost ofwater. Converting irrigated turf lawns to ground covers or mulched areas can result inconsiderable cost savings. Changing watering schedule and landscape management withoutmaking any physical changes in the landscape may save water. A study by the NC CooperativeExtensive Service notes that converting 1,000 square feet of irrigated area to a non-irrigated areamay save up homeowners up to $60 per year.5Incentives for homeowners may be available through the US EPA’s WaterSense program. Theprogram assists homeowners in improving water efficiency and reducing costs by promotingefficient irrigation technologies such as weather-based irrigation controllers and soil moisturesensors.ResourcesUS EPA Water-Efficient Landscaping: Preventing Pollution & Using Resources Wiselyhttp://www.epa.gov/watersense/docs/water-efficient_landscaping_508.pdfNJ DEP Creating Sustainable Communities – A Guide for Developers and Communitieshttp://www.state.nj.us/dep/opsc/docs/Sustainable_Landscape.pdf5 NC Cooperative Extension. How to Plan & Design a Wise-Water-Use Landscapehttp://www.bae.ncsu.edu/programs/extension/publicat/wqwm/ag508_2.html (accessed November 20, 2010).
GREEN BUILDING MANUAL NEW RESIDENTIAL UPDATED 2-MAY -11Rutgers Cooperative Extension. Landscaping for Water Conservation: A Guide for New Jersey.http://njaes.rutgers.edu/pubs/publication.asp?pid=E080Rutgers NJ Agricultural Experiment Station – Low Water Use Landscapinghttp://njaes.rutgers.edu/pubs/publication.asp?pid=fs595Sustainable Sites Initiativehttp://www.sustainablesites.org/Delaware River Basin Commissionhttp://www.state.nj.us/drbc/drbc.htmNJ Drought Information: Ideas for saving waterhttp://www.njdrought.org/ideas.html