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Using Water Wisely: Southwest Data Shows the Promise of Efficiency 2008-08-05 Using-Water-Wisely.pdf

Executive Summary

Water is a precious commodity in the Southwest, yet the rate of water consumption outstrips natural supply. Rapid population growth, excessive water consumption, water pollution, and years of drought have depleted the Southwest’s natural water reserves and put the region at greater risk of a water crisis.

Without a dramatic change from business as usual, the Southwest’s water scarcity problem will only get worse. The population in Arizona, Colorado, Nevada, New Mexico, Texas, and Utah grew by 2.3 percent between 2006 and 2007. At that rate, there would be twice as many people in the region by 2040. Scientists predict that global warming will decrease rainfall and increase temperatures in the Southwest, further exacerbating the problem.

By using existing water efficiency technologies and adopting effective programs to conserve water region-wide, six states in the Southwest could save as much as 5.7 million acre-feet of water per year.

Water Efficiency Could Save up to 5.7 Million Acre-Feet of Water Each Year in the Southwest

Agriculture: Agriculture is responsible for about 70 percent of all water consumption in six Southwestern states (Arizona, Colorado, Nevada, New Mexico, Texas and Utah). Better water efficiency in agriculture could save up to 2.9 million acre-feet of water for the region every year.

• The irrigation techniques used most frequently in the Southwest waste significant amounts of water. For example, the vast majority of all farmland in the Southwest is irrigated with either sprinklers or surface irrigation, which partially floods fields. Both of these common techniques lose significant amounts of water to evaporation, whereas microirrigation, in which water is applied directly to the plants, dramatically reduces evaporation losses.

• Switching fields to microirrigation could reduce water consumption by as much as 0.4 million acre-feet each year in Arizona, 0.9 million acre-feet in Colorado, 0.2 million acre-feet in Nevada, 0.2 million acre-feet in New Mexico, 0.8 million acre-feet in Texas, and 0.3 million acre-feet in Utah.

• Microirrigation has been around for decades and is especially popular in dry areas around the globe, such as Israel, where it is used on 70 percent of all irrigated lands.

Homes: Homes are responsible for about 15 percent of all water consumption in the Southwest. In the residential sector, large water savings can come from cutting down unnecessary water use outdoors. Xeriscape – landscaping designed and maintained in ways that use water efficiently – is generally easier to maintain than a typical yard and is compatible with a wide diversity of flowers, grasses and shrubs.

• Southwestern homeowners consume more water for outdoor use than for all indoor uses combined.

• A five-year study by the Southern Nevada Water Authority found that Xeriscaping reduced total home water consumption by a third.

• Encouraging homeowners to implement Xeriscaping could save 2.7 million acre-feet of water a year. If all new homes built in the Southwest were designed to implement Xeriscaping techniques, it could save another 0.4 million acre-feet of water every year by 2020.

Electricity: Electricity generation is responsible for about 2 percent of all water consumption in the six Southwestern states. Reducing electricity generation from traditional fossil fuel power plants by just 20 percent through greater use of energy efficiency and renewable energy could cut water withdrawals by 140,000 acre-feet every year.

·   Typical ‘once through’ power plants withdraw about 448,000 acre-feet of water a year, depending on the size of the plant. After being used for cooling, the water in such systems is returned to the source along with contaminants and heat from the plant.

·   Developing energy efficiency and renewable electricity sources, such as solar and wind power, would reduce the need for water in power plants.

Business: Businesses are responsible for about 3 percent of all water consumption in the Southwest. Some cities have already found that financial incentives can spur businesses to find new ways to save water. Reducing water consumption in industry by another 2 percent would save the Southwest 25,000 acre-feet every year.

• A program run by Denver Water is expected to save an average of 4,650 acre-feet of water annually by paying businesses to adopt water-saving technologies. This type of broad incentive can encourage innovation in water efficient technologies.

• Several Southwestern cities, including Denver, also give rebates to businesses that install water-efficient versions of common devices, such as high efficiency toilets and urinals.

Southwestern states should use appropriate public policy tools to promote more efficient use of water resources and alleviate the region’s water scarcity problems. Specifically:

• Any new development or heavy water user should have to demonstrate that they have acquired a sustainable water supply, as is the case in Arizona. Farmers should be allowed to sell or lease water saved through efficiency improvements to others, increasing the use of microirrigation and other water-saving techniques.

• States should decrease the amount of electricity generated by coal, natural gas and nuclear power plants, which use large amounts of water. States should meet more of their electricity needs with ultra-low water use generation – primarily energy efficiency and renewable energy sources such as wind and solar power.

• States should cap the water use of new houses to ensure water responsibility and encourage Xeriscape in early stages of development. Additionally, all homeowners should receive incentives for increasing water efficiency and pay higher prices for water use beyond a certain threshold.

• States should develop commercial incentive programs like Denver Water’s program to encourage better use of water-saving technologies and programs in businesses.