Elements of a national, intersectoral water policy can include plans for construction and operation of multi-sectoral water facilities, definition of the legal and regulatory framework for water rights, procedures for surveillance of water use and conflict resolution, incentives frameworks, definition of the role of the private sector in water supply and management, and environmental regulations and flood control provisions, among other considerations.
A basic requirement of a national water policy, and therefore of an irrigation strategy, is a national water assessment. Before proceeding with the design of irrigation projects, a prior decision has to be taken as to how much supplies of irrigation water can be expanded, or whether they can be expanded at all, in light of projected water balances by watershed and nationwide. Only after such a decision has been reached is it appropriate to investigate how to make additional irrigation viable in technical, economic and institutional terms.
A water assessment has to take into account all sources of water, including both groundwater and surface water and non-conventional sources such as desalinized and treated waste water, and all water uses, current and projected. Where there are competing uses, it is necessary to estimate the economic value of water in each category of use and the possibilities of water conservation in existing uses. An assessment also evaluates the waste-assimilation capacities of the water systems in light of the likely loads of waste materials that will be discharged into fresh water, and the economic costs and public health risks associated with poor water quality. As well as direct dumping of wastes into water, considerable amounts of pollution occur via seepage of wastes from cesspools and landfills and runoff of agricultural chemicals. Groundwater is particularly vulnerable to such pollution because natural cleansing mechanisms are practically nonexistent and its contaminants disappear only extremely slowly, if at all. Aquifers in coastal areas are particularly vulnerable to saltwater intrusion as they are pumped down. Rivers are also vulnerable because pollution increases the costs of utilizing water to downstream users, and pollution may make rivers completely unsuitable for some uses. In addition, river-borne pollutants often flow into lakes, estuaries and coastal seabeds where they create other problems.
The case for water assessments has been made in the following way by the World Bank:
Specific options for investment and development must consider the interrelations among different sources of water. Surface and ground-water resources are physically linked, so their management and development should also be linked. Land and water management activities as well as issues of quantity and quality need to be integrated within basins or watersheds, so that upstream and downstream linkages are recognized and activities in one part of the river basin take into account their impact on other parts. Investments in infrastructure may displace people and disturb ecosystems. Thus, water resource assessments need to consider these cross-sectoral implications.43
The possibilities of augmenting year-round access to water supplies through the construction of dams may be included in some water assessments. Dams have a history as long as large-scale irrigation systems, and between 1950 and the late 1980s approximately 35000 large dams were constructed throughout the world.44 However, there is now greater awareness of the difficult environmental and social issues that large dams often pose, and an international dialog is underway on developing new planning procedures for such dams and new criteria for their evaluation. (See
44. Tony Dorcey, Achim Steiner, Michael Acreman and Brett Orlando, Large Dams: Learning from the Past, Looking at the Future, IUCN - The World Conservation Union, IUCN, Gland, Switzerland and Cambridge, UK and The World Bank, Washington, DC, USA, 1997, p. 4.
the referenced IUCN - World Bank paper by Dorcey et al. on large dams (especially pp. 4-13, 19-20 and appendices A1 and A2) for a preliminary statement of planning issues and evaluation criteria.) Future projects for the construction of dams will face more demanding criteria for acceptance but some of them can be feasible if designed conscientiously with these criteria in mind. It is important for designers of dams to keep up to date with the ongoing international dialog on that subject.
In situations of water scarcity, the possibilities of recycling treated waste water and desalinization of sea water need to be examined in a water assessment. For many areas of the Middle East and North Africa it has been decided that recycling waste water, under proper controls, can contribute both to expanding the water supply and improving the environment. A substantial amount of irrigating with waste water is already camed out in several countries of that region, such as Israel, Jordan and Saudi Arabia.45 In the western hemisphere, Mexico has been a leader in the use of treated waste water for irrigation, in its central plateau where competition for water is especially acute. There still are concerns about the quality of waste water and research is underway on efficient ways to improve it. Research in Burkina Faso has found that putting waste water in holding ponds in which water lettuce (Pistia stratiotes) grows can improve the water quality to a level where it can be used to irrigate market gardens.46
A full water assessment will indicate, among other things, the possibilities of developing new water supplies and their approximate costs, the trends in water demands, the possibilities for water conservation in each kind of use and options for improving the efficiency of existing irrigation systems, trends in water quality and classes of measures needed to maintain acceptable quality, and the likely direction and magnitudes of intersectoral water transfers in the future. It should also identify agronomic constraints on irrigation, environmental issues in addition to water quality (e.g. soil deterioration and degradation of natural habitats) and social issues that can accompany water development and water quality issues (e.g. public health concerns, resettlement of populations as a result of both dam construction and the opening of newly irrigated lands). It is only within this kind of framework that irrigation planning should go forward.
Given the increasing importance of policies for water management, the FAO has made a case for complementing a water assessment with a water policy review as well as an assessment. This organization considers that such a review should take place if any of a number of problems emerge, including difficulties in balancing water supplies with demands, deficiencies in the standards of service in supplying water, degradation of water quality, serious inefficiencies in water systems (including irrigation), financial shortfalls in the water sector, inadequacies in the institutions charged with managing water, and symptoms of conflict among water users.47 The guidelines for developing such reviews are provided in the 1995 FAO publication.
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