Scale of water resources development and sustainability: small is beautiful, large is great

Several aspects of water resources and their links with food and energy supply, as well as with natural hazards, have been obscured due to political aims and ideological influences. At the same time, the involvement of politics and ideology testifies to the high importance of water-related issues internationally, and reflects the intensifying unresolved problems related to water, food and energy adequacy, as well as protection from floods and droughts. In an attempt to separate, as much as possible, the essence of problems from the political and ideological influences, several facts and fallacies about water and interrelated issues are discussed, based on data (numbers) rather than on dominant ideological views. The domain of the discussion is generally the entire globe, but, as a particular case, Greece, whose water resources are only partly developed, is discussed in more detail. From a pragmatic point of view, the water infrastructure in developed countries appears to be irreplaceable, although its management is adaptable toward more environmentally-friendly operation. For developing countries, no alternative to large-scale water resources development by engineering means appears plausible. The recent pursuit of renewable energy makes imperative the utilization of the existing and, where possible, the building of new, large hydropower plants, as only these can provide efficient energy storage, which is necessary for the renewable energy provided by nature in highly varying patterns. © 2011 IAHS Press.