Conserving water saves energy and money and preserves fresh water habitat. Much energy goes into transporting water to your residence, and then more is used to heat water for bathroom and kitchen uses. By conserving water it is possible to prevent some of the pollution caused by excessive energy use, such as global warming and acid rain.
Many of the problems relating to water use can be attributed to development in areas where there is an insufficient water supply. For example, although the Southwest has only six percent of the country's fresh water, 31 percent of our water is used to meet the demands of heavy farming and urbanization in this area. As a result, increasing amounts of water are diverted from the Colorado River, and now only a limited amount of water heavy with pesticides and fertilizers reaches the sea.
Water diversion often leads to the destruction of wildlife. When rivers shrink, fish can no longer follow their normal paths of migration to spawn and may fail to reproduce. Diverting water also has a heavy impact on our diminishing wetlands, destroying animal habitat. In California, huge amounts of water are being diverted from Mono Lake's tributaries to be used in Los Angeles County. Mono Lake's water is naturally very salty, but as increased amounts of fresh water are diverted, the salt content has risen. Soon levels may be too high for brine shrimp to survive. If this happens, the food supply for the millions of birds that use Mono Lake as a stopover in their migration routes will be destroyed.
Much of the water we consume comes from underground reserves. If this water is used faster than it is replenished, it can cause land to sink, a process called subsidence. In Florida a few years ago, houses and cars were swallowed by sink holes. Once subsidence occurs, the underground aquifers where water was stored cannot be reformed. According to the U.S. Geological Survey, 35 states are pumping groundwater faster than it is being replenished.
Amory Lovins, Director of Research, Rocky Mountain Institute suggests that "by installing a few simple water-saving devices, costing less than $50, the average household can save more than 30,000 gallons of water and over $60 in water and energy costs each year." He also said that "if every American made this investment as an Earth Day project, enough water could be saved to cover a football field 1,500 miles high, energy equivalent to 7 huge power plants, and over $1.3 billion per year."
STS Actions.
• Show students a glass of water. Ask them to draw a diagram showing where the water originated in their community, what happened to it along the way until it was drawn from the tap. Use the students' ideas to identify misconceptions about water.
• Have students find out what is the source of drinking water in their community. Have then contact the water department to find out their drinking water is purified. Students should prepare maps to show the sources of water in their community, and charts to describe how water is purified.
• Take the students to a waste treatment or water purifying plant. Students can investigate the physical, biological and chemical processes used to purify the water.
• Have students investigate how water is used (conserved) in their school. Have them inspect faucets, toilets, and water usage in the kitchen. Have them draw up a list of recommendations for the school to carry out a water conservation program. Challenge them with coming up with an implementation plan.