Natural water resources include lakes, rivers, streams, ice pack, groundwater, precipitation and oceans. As global climate change begins to affect the distribution of water resources in the United States, water use in all sectors is coming under increasing scrutiny. Residential, commercial and industrial users often compete with agricultural irrigation, hydropower production and navigation for water resources. (See References 1)
Residential, Commercial and Industrial Use
Residential water use includes drinking, cleaning, personal hygiene, lawn care and car washing. Americans get water from public water systems and from private supplies such as wells (see References 2). In the commercial and industrial sectors, most water is used for processing products, with cooling coming in second. Water is also used for laundry, sanitation and landscaping. In 2000, industrial users consumed 5 percent of the available water in the United States (see References 3).
Hydroelectric facilities use the power of flowing water to turn turbines that produce electricity. According to the Department of Energy, the U.S. produces 95,000 megawatts of hydropower per year -- enough to power 28 million households or replace 500 million barrels of oil. Hydropower has come under scrutiny from environmentalists, but new technologies promise to increase the efficiency of power generation while simultaneously decreasing the impact of hydroelectricity on the environment (see References 4).
Only 15 percent of cropland in the United States is irrigated, but that still totals about 55 million acres, including land in highly productive areas such as California. Water for irrigation comes from either groundwater or surface water, raising concerns that heavy use could deplete water supplies in a region to the extent that nonagricultural users are negatively affected. Irrigation has also been linked to increased soil salinity and contamination of groundwater with fertilizers and chemicals through runoff (see References 5).
Navigable waterways are defined as watercourses that have been or may be used for transport of interstate or foreign commerce. Agricultural and commercial goods are moved on water on a large scale in the United States, making navigation an important economic concern. Federal regulations control construction, excavation and disposal in and around navigable waters. Navigation interests may come into direct conflict with other interests, including hydropower and wildlife conservation. (See References 6)
- U.S. Global Change Research Program: Water Resources Sector
- U.S. Geological Survey: Domestic Water Use
- U.S. Geological Survey: Industrial Water Use
- Department of Energy: Hydropower
- Department of Agriculture: The Census of Agriculture, 2007
- Federal Transit Administration: Navigable Waterways and Coastal Zones
Based in central Missouri, Rachel Steffan has been writing since 2005. She has contributed to several online publications, specializing in sustainable agriculture, food, health and nutrition. Steffan holds a Bachelor of Science in agriculture from Truman State University.
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