Chilean hydrology – thirst for power

Dr James Bathurst, of the School of Civil Engineering and Geosciences at Newcastle University, has been on sabbatical at the Universidad Austral de Chile at Valdivia during April-August 2013, researching the impact of forest plantation on soil erosion. In this second of a 3 part series, he discusses hydropower and Chilean politics. This series is based on an article published in the British Hydrological Society’s newsletter Circulation, issue 118, August 2013.

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Chile - Jeinimeni National Reserve

Chile – Jeinimeni National Reserve

Hydropower is at the centre of energy politics. Chile is long on renewable energy resources but short on conventional hydrocarbon resources and has to import, expensively, these latter fuels. A senior energy executive was recently quoted as saying that “Water is Chile’s oil” and indeed hydropower accounts for around 40% of Chile’s electricity generating capacity. Energy demand has greatly increased during Chile’s recent economic boom and its drive to become a fully developed nation by the end of the decade (it is the only South American nation in the OECD). However, the reduced HEP availability due to the drought and expensive fuel imports have driven up energy prices to the detriment of the country’s international competitiveness.

The direct relationship between water and energy costs was illustrated by a fascinating calculation in the leading daily newspaper, El Mercurio, following the first heavy winter rains in May. The rainfall was translated into a runoff input to the reservoirs, which in turn was quantified as a HEP resource of 180 MW, which in its turn allowed a reduction in marginal energy costs (by replacing supply from the hydrocarbon plants) from US$ 310 / MWh to US$250 / MWh.

A proposed hydroelectric scheme is also the cause of one of Chile’s biggest environmental disputes. The HidroAysén scheme in Chilean Patagonia proposes five dams on two rivers to generate 2750 MW at a construction cost (including the transmission line) of over US$ 10 billion. On the one hand the scheme would generate much-needed and environmentally clean power and would provide job opportunities and support development in a remote part of the country. On the other, it would devastate two of the world’s last few big pristine rivers, flood large areas (including part of a national park) and, most controversially, require a 2000-km transmission line driven through some spectacular countryside to carry the electricity to the central and northern regions, presumably with significant losses along the way and open to disruption by a range of geohazards.

Critics also contend that Chile’s needs can be met by a range of alternative renewable energy schemes, less environmentally disruptive and more broadly based (implying a less vulnerable electricity supply). The scheme received government approval in 2011 but a well-organized and somewhat unexpected opposition has delayed implementation. It is likely to feature in the campaigns for the November 2013 presidential election.

Following a loss of momentum in recent decades, Chile once again has an active reservoir building programme. In March 2013 the government launched its National Water Resources Strategy with the aim of ensuring that water shortages should not be an obstacle to the country’s development.

Sixteen reservoirs have been proposed for construction by 2021, to increase the national water storage by 30% and secure 170 000 ha of irrigation. As an indication of the growing demand for reliable water supply for agriculture, they include the first two irrigation reservoirs in the southern rainy regions of The Lakes and The Rivers. The Strategy also includes the development of new water sources such as aquifer recharge. Many of the aquifers are drying up through over exploitation and, apparently, reduced infiltration consequent upon soil erosion (so more surface and less subsurface flow) and increasing urbanization (so more impermeable surface).

Sources and acknowledgements

Most of the above information was taken from Wikipedia and El Mercurio, which regularly discusses water-related issues and which endeared itself to me by once publishing a special supplement containing Manning’s flow resistance equation. I thank Andrés Iroumé (Universidad Austral de Chile), Alejandro Dussaillant (University of Greenwich and Centro de Investigaciones en Ecosistemas de la Patagonia) and Claudio Meier (Universidad de Concepción) for additional information and for checking what I have written but I remain responsible for any misrepresentation. I also thank Andrés as my host at the Universidad Austral de Chile, Chile’s Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) (MEC contract 80120037) as my financial sponsor and my colleagues at Newcastle University (who took on my duties) for enabling me to undertake such a fascinating and enriching sabbatical.

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