The relatively high cost of treating and delivering water has led many world governments to subsidize water for agriculture and household use. For example, some U.S. farmers pay as little as 1¢ to 5¢/1000 liters they use in irrigation, while the public pays from 30¢ to 80¢ per 1000 liters of treated water for personal use. Farmers in the Imperial Irrigation District of California pay $15.50 in delivery fees for 1.2 million liters of water. Some investigators suggest that if U.S. farmers paid the full cost of water, they would have to conserve and manage irrigation water more effectively.
The construction cost subsidy for federally-subsidized western U.S. irrigated cropland amounts to about $5,000 per hectare, and represents an annual construction cost subsidy of about $440 per ha/yr over the life of the project. The total annual government subsidy is estimated to range from $2.5 billion to $4.4 billion for the 4.5 million hectares of irrigated land in the western United States. Worldwide, from f94 to 1998 governmental water subsidies totaled $45 billion per year for non-Organization for Economic Cooperation and Development (OECD) countries and $15 billion for OECD counties. During the same period, agricultural subsidies per year total $65 billion for non-OECD and $355 billion for OECD countries.
Fair Water Pricing
The objectives of fair water pricing are: to seek revenue to pay for the operations and maintenance of water availability; improve water-use efficiency; and recover the full costs of water pumping and treatment. However, in general there appear to be problems with some private, for profit companies operating water systems for communities and regions. Often the companies operate as monopolies which can lead to unfair pricing practices.
If U.S. prices of gasoline and diesel energy increase to approximately $10 per gallon, it follows that irrigation costs will continue to escalate from the current $2.9 billion per year. Since vegetable and fruit crops return more per dollar invested in irrigation water than field crops, farmers may have to reassess the crops they grow. For example, in Israel 1000 liters of water from irrigation produces 79¢ worth of groundnuts and 57¢ worth of tomatoes, but only 13¢ worth of corn grain and 12¢ worth of wheat.
Conflicts over Water Use
The rapid rise in withdrawal of freshwater for agricultural irrigation and for other uses that have accompanied population growth has spurred serious conflicts over water resources both within and between countries. In part the conflicts over fresh water is due to the sharing of fresh water by countries and regions. Currently there are 263 transboundary river basins sharing water resources. Worldwide such conflicts have increased from an average of 5 per year in the 1980s to 22 in 2000. In 23 countries where data are available, conflicts related to agricultural use of water cost an estimated $55 billion between 1990 and 1997.
At least 20 nations obtain more than half their water from rivers that cross national boundaries, and 14 countries receive 70% or more of their surface water resources from rivers that are outside their borders. For example, Egypt obtains 97% of its freshwater from the Nile River, the second longest in the world, which is also shared by the Sudan, Ethiopia, Egypt, Burundi, Kenya, Rwanda, Tanzania, Zaire, Eritrea, and Uganda. Indeed, the Nile River is so overused that during parts of the year little or no freshwater reaches the Mediterranean Sea.
Conflicts over Water
Historically, the Middle East region has had the most conflicts over water, largely because it has less available water per capital than most other regions, and every major river crosses international borders. Furthermore, the human populations in these countries are increasing rapidly, some having doubled in the last 20 to 25 years, placing additional stress on the difficult political climate.
River Water Sources
The distribution of river water also creates conflicts between several U.S. states as well as problems between the U.S. and Mexico. California, Nevada, Colorado, New Mexico, Utah, Arizona, and Mexico all depend on Colorado River water. In a normal year, little water reaches Mexico, and little or no water reaches the Gulf of California.
Conserving Water Resources
Conserving world water must be a priority of individuals, communities, and countries. An important approach is to find ways to facilitate the percolation of rainfall into the soil instead of allowing it to runoff into streams and rivers. For example, the increased use of trees and shrubs make it possible to catch and slow water runoff by 10% to 20%, thereby conserving water before it reaches streams, rivers, and lakes. This approach also reduces flooding.
Maintaining crop, livestock, and forest production requires conserving all water resources available, including rainfall. Some practical strategies that support water conservation for crop production include: monitoring soil water content; adjusting water application needs to specific crops; applying organic mulches to prevent water loss and improve water peculation, through reduced water runoff and evaporation; using crop rotations that reduce water runoff; preventing the removal of biomass from land; increasing use of trees and shrubs to slow water runoff; and employing precision irrigation in water delivery systems, such as drip irrigation, that will result in efficient crop watering.
In forest areas, it will be necessary to avoid clear cutting and humans should employ sound forest management. Trees also benefit urban areas that have high rates of runoff. Since water runoff is rapid from roofs, driveways, roads, and parking lots, the water can be collected in cisterns and constructed ponds. Estimated runoff rates from urban area were 72% higher than areas with forest cover.
Given that many aquifers are being over drafted, government efforts are needed to limit the pumping to sustainable withdrawal levels or at the known recharge rate. Integrated water resource management programs offer many opportunities to conserve water resources for everyone, farmers and the public. By the way, i proud of support the best Drill Presses and the Best Woodworking books.