Water for people.pdf - WHO Thailand Digital Repository

3 3 0 / M A N A G E M E N T C H A L L E N G E S : S T E W A R D S H I P A N D G O V E R N A N C ERecognizing and Valuing the Many Faces of WaterValue functionsThe economics of water resources rarely influence waterpolicy, even in water-short regions. As a result, theprincipal asset of the water resource base remains highlyundervalued and readily used without much concern forits value to others, the structural role of water in theeconomy and its in situ value as an environmental asset(UNDESA, 1998).Water functions and values can be described from various points ofview. Water contributes to a complex system of services and resourcesand each of these has an economic benefit, although it may not alwaysbe easy to estimate its value. Water benefits are not all the same: someare the result of economic activities; others have an indirect link witheconomic activities, while there are also benefits that do not come fromeconomic activities. Defining water’s different benefits or values is notonly difficult but often also contentious. Protagonists of productivewater use and those of water’s nature values often engage in disputesover water use. However, valuing water is a means of providinginformation for participatory decision-making about water use. Thevalue of water depends to a large extent on where it is available. Itsvalue is site-specific and, because of this, it is also time-bound: watercaptured by a dam or in a lake can be used as and when required,while water in a river is only available when there is a flow.As discussed above, water represents many values to society, andunderstanding the complex totality of these values is an importantelement in integrated water resources management. An assessmentreport completed by the Water Supply and Sanitation CollaborativeCouncil (WSSCC), the World Health Organization (WHO) and theUnited Nations Children’s Fund (UNICEF) in 2000 (WHO/UNICEF, 2000)found that water resources have traditionally been managed on thebasis of water availability and historic demands, whereby prioritieswere set to serve one subsector before another. In about 50 percentof the countries, drinking water and sanitation have been givenhighest priority above other subsectors of water utilization.Not surprisingly, the perceived value of water for domesticpurposes is usually much higher than its value for irrigation. Animportant finding (similar to that emerging from the irrigation data) isthat people, and notably poor people of developing countries, value areliable supply much more than the intermittent, unpredictable supplycommonly experienced (World Bank, 1993). In terms of opportunitycost, the short-term water value in hydropower in industrializedcountries is typically quite low, often no higher than the value inirrigated agriculture (Gibbons, 1986). Long-term values are evenlower. Whether or not hydropower is an economic propositiondepends greatly on particulars – of the economy, of the power sectorand of the water sector. In developing countries the demand forpower is growing very rapidly. It has been put forth (Goodland, 1995)that the high environmental cost of alternative sources of powerexplains why hydropower is a particularly attractive option in manydeveloping countries. It is generally stated that hydropower is a nonconsumptiveuse and therefore does not impose costs on others. Bymodifying flow regimes and the timing of water to downstream users,however, hydropower installations can impose major costs on otherusers (see chapter 10 for more details on water and energy). The keyissue is not consumptive or non-consumptive use, but the costsimposed on others by a particular use of a resource.Surface water bodies and aquifers are generally hydraulically linkedto aquatic ecosystems and they provide, usually on a seasonal basis,base flows that permit the good functioning of the ecosystems (e.g.the Lake Chad in West Africa or the Okavango Delta in Botswana). Inreturn, water resources systems benefit from aquatic ecosystems thatcan play a role of buffer and filter (e.g. the Niger Delta in Mali, theSud region on the Nile basin). Exchanges between water resourcessystems and aquatic ecosystems are usually intrinsically complex interms of valuing water and insufficiently understood due to lack ofmonitoring. The multiple roles of the aquatic ecosystems confer avalue to water and to humanity that may exceed the one derived frommost other sources such as irrigation or hydropower. Costanza et al.(1997) valued the ecosystem services of different freshwaterecosystem types based on the Ramsar Convention on Wetlands andTable 13.1: Value of aquatic ecosystem water servicesEcosystem types Total value per hectare (US$ per year) Total global flow value (US$ billion/ year)Tidal marsh/mangroves 6,075 375Swamps/floodplains 9,990 1,648Lakes/rivers 19,580 3,231Total 5,254Global and per hectare values of ecosystems have been calculated based on the estimation of the indirect values of the aquatic ecosystems in flood control, groundwater recharge, shorelinestabilization and shore protection, nutrition cycling and retentions, water purification, preservation of biodiversity, and recreation and tourism.Source: Costanza et al., 1997.