Water for people.pdf - WHO Thailand Digital Repository

D E V E L O P I N G E N E R G Y T O M E E T D E V E L O P M E N T N E E D S / 2 5 9Proposed large-scale hydropower projects often face pressurefrom environment and human-rights groups as the resulting floodingof large areas of land often leads to the displacement of people livingin this area, e.g. in the 18.2 GW Three Gorges dam project in China.The south-eastern Anatolia project (see box 10.3) shows a newand integrated approach for large-scale hydropower projects.Small-scale hydropowerGrid system/local supplyIt can often be shown that decentralized systems such as hydropowerare competitive with grid power at low consumption levels, but are notcompetitive at higher levels. This is because once the capital costs ofgrid extension have been met, any increases in consumption affectonly the generation costs, while the costs of distribution per unit ofconsumption actually fall. In contrast, with a decentralized system eachincrement of energy use, or power, requires additional supply capacity.Advantages/disadvantages of small-scale hydropowerSmall hydropower plants and especially mini- and micro-hydropowerplants normally do not imply huge dam constructions. Therefore theadverse health effects and the impact on the environment can bedescribed as low (see box 10.4).EnvironmentIt has been estimated that a 1 MW small-scale hydro plant, producing6,000 MWh in a typical year, avoids the emission of 4,000 tons ofcarbon dioxide and 275 tons of sulphur dioxide, compared with a coalfiredplant of equivalent output, while supplying the needs of 1,500families. The present installed capacity of small hydro in the EuropeanUnion (EU) avoids annual emissions of 36 million tons of carbon dioxide.The Italian Small Hydro Association, APEI, uses similar figures as apromotional slogan, which also states that, based on carbon dioxideabsorption figures for woodlands, the non-construction of a 1 MWhydro plant is equivalent in terms of atmospheric carbon dioxideincrease to the destruction of a 500-hectare wood. It can therefore besaid that small hydropower technology involves low environmentalimpacts and is a key technology for sustainable development. This isdemonstrated by the successful deployment and manufacture of smallhydro equipment in such underdeveloped countries as Nepal and Peru.There are several aspects of water flow that have to be takeninto consideration.■ A minimum flow has to be maintained in the river to ensurethe life and reproduction of fish, and the free passage ofmigratory fish.■ The determination of an acceptable minimum flow is a key issuein determining the economic viability of a scheme.■ Run-of-river hydropower schemes have minimal visual impact.■ The principal, permanent impacts are on the depleted stretch ofthe watercourse, where mitigating measures need to be taken tosustain the river ecology and fisheries.■ Some types of turbines also provide increased oxygenation ofthe tailrace water, leading to improved water quality.Box 10.3: GAP – a paradigm shift in water resources developmentThe south-eastern Anatolia Project (GAP) has been conceivedand implemented as a means of integrating water resourcesdevelopment (twenty-two storage dams and nineteenhydropower plants on the Euphrates and Tigris river systems)with overall human development in the poorest and mostunderdeveloped region of Turkey. Sustainability (social,spatial, environmental and economic), participation (of allstakeholders) and intersectoral coordination and integrationare the hallmarks of this new approach. The strategyimplements special programmes and projects concerned withbasic social services (education, health, housing), genderequity, urban management, participatory irrigationmanagement, agricultural extension, environmentalprotection, institutional and community capacity-building, andpublic empowerment, under the overall coordination umbrellaof a special purpose vehicle known as the GAP RegionalDevelopment Agency. Initial results of instituting irrigation inthe Harran plains are positive. The ratio of landless farmershas dropped from 40 percent to around 23 percent and theratio of share croppers increased from 27 percent to 57 percent;migration from these areas dropped from 70 percent to 12percent and in some areas in-migration started. Despite theexistence of certain problems that need to be tackled,outcomes indicate that GAP shows promise, not only as a toolfor achieving progress in hydraulic engineering, but also asan instrument for social change.Source: Prepared for the World Water Assessment Programme (WWAP) by the southeasternAnatolia Project (GAP), 2002.