48
Rossing
Water Scarcity, Glacial Melt, and Local Governance Responses in Bolivia By 2020 climate change is likely to affect the water supply and overall livelihood of up to 77 million people who live in river basins supplied by glacial melt or snowmelt in the Andes region (IPCC 2007b). The projected disappearance of tropical glaciers will cause severe water shortages in the arid and semiarid Andes regions of Bolivia, Colombia, Ecuador, and Peru (Kaser 1999). We use the case of glacial melt in Bolivia to highlight some of the resulting water stress dynamics. Bolivia has one of the largest concentrations of poverty and social and economic inequality in Latin America, and glacial melt threatens not just to diminish water availability but to exacerbate existing inequalities in the country. A promising move is the current decentralization of water resources management, under the policy framework known as Agua para Todos (Water for Everybody). Glacial melt has been occurring in the Andes for centuries, but so slowly that the retreat of the glaciers was not widely noted. Within the last century, however, melting has accelerated and has been documented with photographs showing glacier coverage declining year after year. This acceleration in the disappearance of glaciers can be linked to higher summer temperatures and declining precipitation. If the glaciers were stable, that is, if they released no more water than they received in the form of precipitation, their net overall effect on the annual water supply would be zero. Their effect would be restricted to flow regulation: during the summer, which is the wet season, they would absorb precipitation thereby reducing runoff and stream flows. During the winter, which is the dry season, that accumulation would gradually melt, contributing to stream flow, which would otherwise be low during the dry season. In other words, a stable glacier would help even out the flow of water over the year but would not affect the total volume of water available. A melting glacier, on the other hand, does increase water supply while it is melting, but of course, once it has disappeared completely it will no longer add to the flow or affect the timing of water flow. The current situation, with melting glaciers, has helped accommodate increasing water demand and has ensured a continuing flow of water during the dry season. However, the melting has accelerated, causing the volume of glacial lakes to increase to levels at which glacial lake outbursts probably now present a real threat to people’s lives and property. When the glaciers have disappeared completely, not only will the people of the Andes no longer receive the boost to water supply they have come to rely on, but they will also lose the regulatory function that the glaciers perform. Thus