Environmental Problems, Their Causes, and Sustainability 1

water waste by about 84% while irrigating 44% moreland. Israel now treats and reuses 30% of its municipalsewage water for crop production and plans to increasethis to 80% by 2025. The government also graduallyremoved most government water subsidies toraise the price of irrigation water to one of the highestin the world. Israelis also import most of their wheatand meat and concentrate on growing fruits, vegetables,and flowers that need less water. Researchershave also found that farmers can often sustain grainyields by using one fourth less irrigation water as longas crops receive enough water during their criticalstages of growth.Many of the world’s poor farmers cannot afford touse most of the modern technological methods for increasingirrigation and its efficiency. Instead they usesmall-scale and low-cost traditional technologies.Some (in Bangladesh, for example) use pedalpoweredtreadle pumps to move water through irrigationditches. Others use buckets or small tanks withholes for drip irrigation.How Can We Waste Less Water in Industry,Homes, and Businesses? Copy Nature, RaisePrices, Improve EfficiencyWe can save water by using yard plants that needlittle water, using drip irrigation, raising water prices,fixing leaks, and using water-saving toilets and otherappliances.Figure 15-22 lists ways to use water more efficiently inindustries, homes, and businesses. Many homeownersand businesses in water-short areas are copying natureby replacing green lawns with vegetation adapted to adry climate (Figure 15-23). This win-win approach iscalled Xeriscaping (pronounced “ZEER-i-scaping”),and reduces water use by 30–85% and sharply reducesthe need for labor, fertilizer, and fuel. It also reducespolluted runoff, air pollution, and yard wastes. Somepeople in dry areas collect rainwater from gutters inlarge plastic barrels on wheels and use it to water theirflowers and gardens.About one-fifth of all U.S. public water systems donot have water meters and charge a single low rate foralmost unlimited use of high-quality water. Manyapartment dwellers have little incentive to conservewater because water use is included in their rent. InBoulder, Colorado, introducing water meters reducedwater use by more than one-third.Because of laws requiring water conservation, thedesert city of Tucson, Arizona, consumes half as muchwater per person as Las Vegas, a desert city with evenless rainfall and less emphasis on water conservation(Spotlight, p. 326).In the United States, flushing toilets with waterclean enough to drink is the single largest use ofSolutionsReducing Water Waste• Redesign manufacturing processes• Landscape yards with plants that requirelittle water• Use drip irrigation• Fix water leaks• Use water meters and charge for all municipalwater use• Raise water prices• Use waterless composting toilets• Require water conservation in water-short cities• Use water-saving toilets, showerheads, and frontloadingclothes washers• Collect and reuse household water to irrigatelawns and nonedible plants• Purify and reuse water for houses, apartments,and office buildingsFigure 15-22 Solutions: methods of reducing water waste inindustries, homes, and businesses. Which two of these solutionsdo you believe are the most important?Figure 15-23 Solutions: Xeriscaping. This technique can reducewater use by as much as 85% by landscaping with rocksand plants that need little water and are adapted to the growingconditions in arid and semiarid areas. The term Xeriscape ® wasfirst used in 1978 in Denver, Colorado, and means “water conservationthrough creative landscaping.”http://biology.brookscole.com/miller14325