In fact, 97 percent of the world’s water lies in the oceans and seas and 2 percent is locked up as glacial ice, leaving only 1 percent available for human use. Human demand for water has risen at remarkable rates as a result of increasing population and water use, while at the same time that remaining 1 percent of useable water is being spoiled by pollution from industrial, commercial, agricultural and residential sources, thus reducing its availability for our consumption. The Futurist reported in a 1999 forecast that as a result “water scarcity could threaten 1 billion people by 2025.”
Why do water shortages happen? Besides pollution, often it’s because development outpaces infrastructure. Local water service can’t keep up with the demands of new homes and commercial structures because of lack of supply, treatment capacity or quantity of pipe and pumping stations. Environmental concerns, regulations or legal decisions can restrict the amount of water that can be used to serve an area’s population, and increases in water use require greater stream inflows of clean water. As previously mentioned, weather also can create water shortages when drought or insufficient snowfall accumulation fails to replenish reservoirs or when flooding contaminates the water supply.
Mechanical or structural shortcomings, such as leakage through broken pipes, can also cause water shortages. In older systems, 50 percent or more of treated water can be lost through major leaks, and having 10 to 15 percent of all treated water “unaccounted for” is considered an acceptable loss by suppliers.
These examples underscore the importance of responsible water use by everyone concerned with plants and irrigation systems. Xeriscape, a concept that was developed in 1981, is quality landscaping that conserves water and protects the environment. Xeriscape applies to all regions of the world, and through its principles, promotes quality design that balances the lawn area, shrub and flower plantings and the hardscape. The mission of Xeriscape is to change the attitudes and irrigation habits of professional and amateur landscape managers because proper water management provides the greatest opportunity for water conservation in the landscape. Properly applied, Xeriscape justifies the slogan, “Plants and irrigation systems don’t waste water, people do.”
Xeriscape has seven basic principles: planning and design; soil improvement; appropriate plant selection; practical turf areas; efficient irrigation; mulching; and appropriate maintenance. Of these principles, the guidelines for practical turf areas have received most of the attention.
The original idea incorporated into Xeriscape about turfgrass was “limited turf use.” Today’s Xeriscape movement incorporates a more holistic approach that recognizes that the human factor and landscape water management have as much effect on water consumption as the type of plants used. The Xeriscape movement focuses on turfgrass because of the tremendous potential for irrigation water abuse in the name of maintaining green turfgrass.
In contrast to the initial perspective on turfgrass outlined in early Xeriscape principles, Dr. J.B. Beard and Dr. R.L. Green conducted a study called "The Role of Turfgrasses in Environmental Protection and Their Benefits to Humans," which was published in the Journal of Environmental Quality. The study provides strong evidence of the benefits provided by turfgrass.
In addressing the issue of water conservation, Beard and Green wrote:
- Trees and shrubs can use more water than turfgrass
- Drought-resistant plants are not necessarily low water users
- Adjacent trees and shrubs reap benefits of turfgrass watering
- Turfgrass’ brown color during drought periods is entirely normal
- Water conservation can be achieved with low water-use turfgrasses
The author is executive director, International Turf Producers Foundation, Rolling Meadows, Ill.
See Lawn & Landscape Online next Tuesday, April 9, for the second installment of "Conserving Water With Turfgrass."