BMP #4 - Water-Efficient Landscaping
Background
In most locations, traditional landscapes require supplemental water to thrive. For example, Kentucky bluegrass is native to regions that receive in excess of 40 inches per year of precipitation, but it is commonly planted in areas across the country that receive much less precipitation. To make up the difference between a plant's water requirement and the natural precipitation in your area, additional water must usually be added in the form of irrigation. Depending on your climate, water applied outdoors may be a substantial portion of your total water use. If your facility includes any irrigated landscape, then exterior water use should be an important part of your overall water efficiency program. These principles apply to traditional landscapes, as well as cemeteries, golf courses, or other nontraditional landscapes.
There are two facets of outdoor water use efficiency
- Designing a landscape that requires minimal supplemental water; and
- Designing, installing, and maintaining an irrigation system that applies the appropriate amount of supplemental water in an efficient manner (see BMP #5).
Water-efficient landscapes using native and other "climate appropriate" landscape materials can reduce irrigation water use by more than 50 percent, stand up better to drought, reduce drought loss or damage, and require less time to maintain, lowering maintenance costs. Reduced turf and other irrigated areas can also significantly reduce time and money spent mowing, fertilizing, removing green wastes and maintaining landscapes.
For more information on this and other FEMP Water Efficiency Best Management Practices (BMPs), please see the resources section.
Operation and Maintenance Options
- Periodically review all landscape service and maintenance agreements to incorporate a high priority for water, chemicals, and energy efficiency.
- Consider hiring landscape contractors that focus on water-efficient or climate appropriate landscaping. Recommend existing contractors attend courses or seminars to learn these techniques.
- Encourage landscape contractors to report and/or fix problems. Many landscape contractors not only install and maintain the plants in your landscape, but also install and maintain the irrigation system. They can help identify and report leaks or other inefficiencies in the landscape.
- Add mulch to plant beds. Mulch decreases the water lost from the soil by evaporation and also helps reduce weed growth.
- Maintain a sufficient quantity of good topsoil of 4 to 6 inches to capture the storm water as it falls and not let it run off and to release the moisture back to the plant material over time which may reduce irrigation requirements.
- Recirculate water in decorative fountains, ponds and waterfalls and shut off when possible to reduce evaporation losses. Check water recirculation systems annually for leaks and other damage. Consider using non-potable water in these systems.
- Alternate your turf mowing height between low and high levels. This encourages roots to grow deeply and helps allow plants to go longer between watering sessions.
- Keep the irrigated landscape weed free so that valuable water is consumed only by decorative landscape.
- Stop using water to clean sidewalks, driveways, parking lots, tennis courts, pool deck, and other hardscapes.
Retrofit Options
- Select drought tolerant or climate appropriate turf, trees, shrubs and ground cover when replanting landscaped areas.
- Consider reducing the area of turf in your landscape. Most turf requires substantially more water than planted beds, especially if the plants are climate appropriate and covered with mulch.
- Eliminate "strip grass" to the greatest extent possible. Small strips of grass, common in parking islands and between sidewalks and the roadway are hard to maintain and difficult to efficiently water. Use bushes, mulch, or permeable hardscape, instead.
- Implement low-impact development techniques such as making parking lot islands depressions instead of raised curb areas to capture and retain moisture.
Replacement Options
- Replace or install the entire landscape with climate appropriate, water-efficient plant material. You may be able to design a landscape that doesn't require the use of supplemental water.
- Design the landscape so plants with similar water needs are grouped together (i.e., hydrozoning). This allows for more efficient irrigation.
- Ensure the landscape is properly designed from the start. Hire a licensed landscape architect or a qualified site planner/designer. Those who design with water efficiency in mind limit the clearing of each lot allowing native vegetation to remain. This increases recharge and limits surface runoff, thereby limiting the size of the stormwater pond(s).
- Check to ensure the soil does not need improvement before installing a landscape. Depending on the soil type, it may need to be amended to ensure water is delivered to the plant in an efficient manner (i.e., good absorption and water holding capacity).
- Use turf only where it is needed, avoiding long narrow areas that cannot be irrigated effectively.
- Ensure trees are planted at the appropriate depth.
- When designing the new landscape, avoid the use of ornamental water features.
Water-Efficient Landscaping Resources
Some of the following documents are available as Adobe Acrobat PDFs. Download Adobe Reader.
Air Force Civil Engineer Support Agency. Air Force Water Conservation Guidebook, May 2002.
American Society for Landscape Architects.
Arizona Municipal Water Users Association. Facility Manager's Guide to Water Management, Version 2.3 March 2003.
Denver Water. Principles of Xeriscape.
EPA's GreenScapes Program.
EPA's Water Efficient Landscaping: Preventing Pollution and Using Resources Wisely. (PDF 1.7 MB).
Federal Highway Administration, Roadside Use of Native Plants.
General Services Administration. Water Management: A Comprehensive Approach for Facility Managers.
Military Handbook: Water Conservation. MIL-HDBK-1165. April 1997. (PDF 572 KB).
New Mexico Office of the State Engineer. A Water Conservation Guide for Commercial, Institutional, and Industrial Users, July 1999. (PDF 2.2 MB).
North Carolina Department of Environment and Natural Resources. North Carolina Water Efficiency Manual for Commercial, Industrial, and Institutional Facilities, 1998. (PDF 2.0 MB).
US Department of Agriculture PLANTS Database, Links Page: http://plants.nrcs.usda.gov/links.html.
U.S. Department of Energy. FEMP Focus: Fort Meade Saves Resources, Energy, and Money by Reusing Water, January/February 2002.
Vickers, Amy. Handbook of Water Use and Conservation. WaterPlow Press. Amherst. 2001.
Check with your local water utility for resources on regional water-efficient landscaping.