This industry consists of establishments primarily engaged in operating water supply systems for the purpose of irrigation. Establishments primarily engaged in operating irrigation systems for others, but do not themselves provide water, are classified in SIC 0721: Crop Planting, Cultivating, and Protecting.
221310 (Water Supply and Irrigation Systems)
As environmentalists, scientists, health officials, and policy analysts looked ahead to the most pressing problems facing the twenty-first century, the balance of demand and availability of fresh water was near the top of the list of concerns. With population figures booming through much of the world, particularly in developing countries, coupled with skyrocketing demand for clean water and delicate and imperiled ecosystems depending on ever more precarious water supplies, it was believed that innovative irrigation systems were required to stave of environmental and social catastrophe.
According to the United Nations Food & Agricultural Organization's report, "Unlocking the Potential of Agriculture," by 2030 world food production will need to increase about 60 percent to adequately feed the 2 billion more people expected to populate the planet. Agriculture consumes about 70 percent of all water withdrawals, according to Appropriate Technology, and the water required to yield an average person's adequate diet
exceeds the quantity that person drinks by a factor of about one thousand. As a result, irrigation systems will require dramatic innovation to avoid potentially serious social conflict stemming from increased competition for scarce water resources.
In the United States, there were some 1,385 establishments engaged primarily in operating water irrigation systems in 2003, with total annual sales of $783.3 million and employing nearly 11,000. The early and mid-2000s saw many of these establishments partnering with scientists to implement new technologies designed to boost irrigation efficiency.
The Center for Irrigation Technology at the California State University described irrigation as the artificial application of water to crops to ensure adequate moisture for growth. Irrigation systems ship water from its source to where it is needed. In the United States in the early 2000s, approximately 64.1 percent of withdrawn ground water was used for irrigation.
Water supply systems primarily utilized for irrigation purposes are in operation all over the world. Generally, water for irrigation falls under the responsibility of a water management district. These entities can be local, state, or federally operated public agencies or mutual associations, private agencies, or co-ops. Some are forprofit organizations, but most fall in the category of nonprofit.
Many technological advances during the twentieth century resulted in the expansion of irrigated agriculture and of the construction of dams and reservoirs to regulate the distribution of water resources. There are actually four sources of water available for irrigation purposes: ground water, surface water, atmospheric water, and ocean water. The most widely used of these is surface water, which comes in the form of rivers, streams, lakes, and oceans. Ocean water is the least utilized of these for irrigation purposes, except in arid areas such as the Middle East where desalination projects brought new technology to agricultural development.
Irrigation water supply systems are structured differently in different parts of the United States. Large irrigation systems are prevalent mainly in the western United States, while other areas of the country generally experience enough rainfall to satisfy agricultural requirements. However, irrigation projects of some kind dot the whole country. Water supply systems in the western United States fell off in total surface irrigated acreage in the closing decades of the twentieth century, while the eastern areas of the country showed an increased use of irrigation systems, despite the rainfall advantages they enjoy. Nonetheless, approximately 75 percent or more of harvested cropland in several Western states is irrigated, and the greatest volume of irrigated water use remains in the western and southeastern states.
As of 2004, there were four basic irrigation systems in use. Those systems were: surface systems that employ wild flood, border, basin, and furrow methods; sprinkler systems that use hand-moved and mechanically-moved aluminum pipe, plastic hose, and solid set arrangements; drip systems that are placed above or below the ground; and sub-surface systems that encourage a high water table to rise in the root zone of the plant.
Attaining irrigation efficiency for the user is a top goal of the districts and water resource departments that monitor the water supply systems. Every effort is made to schedule the release of water to most effectively meet the crops' water needs. Water is expensive, so it benefits the supplier as well as the user to make optimum use of it.
Water pricing systems for irrigation vary throughout the country. Water from surface storage facilities is less expensive than water from state water projects (SWP). In California alone, there are approximately 385 water districts. These include commercial water service agencies and mutual associations that sell water at cost for agriculture within the district service area. Some of the organizations are nonprofit. Each water supplier provides the water within a structure that allows it to set the cost and objectives according to its own policies. The result is that there are many water pricing systems in use. In the early 2000s, the water price range for agricultural water varied from $1 to $300 per acre-foot, which often dictated the type of crops that a grower could afford to irrigate.
The severity of the world water outlook was such that the Worldwatch Institute called for a so-called blue revolution to radically reduce water depletion. Such a wholesale restructuring of the world's handling of water supplies called for major technological overhauls alongside management policy changes. In the early 2000s, many analysts looked to desalination as the most hopeful avenue for addressing the world's impending water shortages. But as a means of providing water for agriculture, desalination was not yet realistic, given the huge quantities of energy consumed in the process.
One of the most promising efforts was in developing "drip irrigation" systems, which could decrease water use by as much as 70 percent. First developed in the 1960s, drip irrigation utilized low-cost plastic pipes that feed filtered water directly into the soil via tiny holes punctured in the tubing. This method conserves water, prevents run-off of nutrients from overly-flushed soil, and uses less energy than traditional irrigation techniques.
Micro irrigation was increasingly utilized by commercial farmers in arid regions of developed countries, particularly the United States, to supply water directly to the soil at intermittent intervals. Running through pipes along or just under the surface of arid soil, micro irrigation avoids the waste that accompanies channel irrigation and wild flooding irrigation, where large amounts of water run over the soil, only some of it actually absorbed into the soil. Micro irrigation systems were, in the early 2000s, fairly expensive, thus limiting their employment primarily to large commercial farmers, whereas farmers and planners in water-scarce third world regions most in need of efficient irrigation systems were reluctant to introduce micro irrigation due to the hefty initial investment in the equipment involved.
On the management side of the equation, many U.S. communities began conducting regular water audits to ensure that the area's irrigation systems were running at optimal efficiency, judged in terms of water leakage, coverage area, and water pressure as measured against the community's historical water needs. Increasingly, water audits were a central component of community planning and an element in the determination of water permits for operators of irrigation systems. Digital orthophotographic technology, meanwhile, was developed for use in assessing a broad geographical area's landscape, plant types, and other measures to assure the land and residents allocated their water supply efficiently and sustainably.
Clarke, Rory. "Water Crisis?" The OECD Observer, March 2003.
Meeks, Phillip. "How Does Your Garden Grow?" Planning, May 2002.
"Micro Irrigation." Appropriate Technology, June 2003.
"More Crop per Drop." Appropriate Technology, June 2003.
"Survey: Irrigate and Die." The Economist, 19 June 2003.
"Water Use Is Unsustainable." Appropriate Technology, June 2003.