Water Management and Treatment

Water Management

Water management is usually supervised by governments through designated governmental agencies. Their main task is to ensure an adequate quantity and quality of water for the use of people, society, and the economy. In many countries, the institutions that are set up to supervise water management also deal with the protection of water against pollution and the protection of a country's territory against floods. Because the issues of water management are of vital global importance, many have broader implications and must be dealt with at the international level. For example, European Union member states act collectively under the “Water Framework Directive” or the “Flood Directive.” International cooperation in this field is also carried out by the United Nations Educational, Scientific and Cultural Organization (UNESCO). Specialized nongovernmental organizations have also been playing a vital role recently in influencing the decisions taken in the field of water management.

Water Resources

Water belongs to the category of “depletable natural resources”; at the same time, it is also considered one of the “renewable resources.” There are three basic groups of resources for meeting water needs (Table 1):

• Atmospheric precipitation and deposits
• Underground waters at deep water-bearing layers (with no direct recharge of surface waters)
• Surface waters (river runoff comprising surface and shallow ground runoff)

Water Needs

Water needs are determined by the quantity of water necessary for the human population and for the functioning of those sectors of the economy that are active in a given area (region, country, continent): agriculture and forestry, industry, electrical power generation (especially hydroelectric power generation), municipal economy, and inland ship and cargo transport.

Table 1 Renewable water resources and water availability by continents

Sources: Water resources data are from World Water Resources and Their Use (a joint State Hydrological Institute/UNESCO product). Retrieved December 1, 2009, from http://webworld.unesco.org/water/ihp/db/shiklomanov. Population data are from Population Reference Bureau's 2007 World Population Data Sheet. Retrieved December 1, 2009, from http://www.prb.org/pdf07/07WPDS_Eng.pdf. Potential water availability per capita calculation is by the author.

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Figure 1 Total renewable freshwater resources per capita (cubic meters per person): long-term annual average

Sources: Data from EUROSTAT (Statistical Office of the European Communities), FAO (Food and Agriculture Organization), OECD (Organisation for Economic Cooperation and Development), and UNSD (United Nations Statistics Division). Map from UNSD Environmental Indicators, “Water Resources: Long-Term Annual Average.” Retrieved December 8, 2009, from http://unstats.un.org/unsd/environment/waterresources.htm.

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