Large Dams And Climate Crisis
By Countercurrents.org
22 September, 2012
Countercurrents.org
Climate crisis is creating uncertainties, in many areas, especially to the world of water. No continent will be harder hit by climate crisis than Africa.
Citing the Intergovernmental Panel on Climate Change Lori Pottinger in the article “A Risky Climate for Big Dams in Africa” [1] writes: African river basins will be especially affected by climate change. There will be worse droughts and more extreme floods.
Lori Pottinger mentions a bitter fact: “[A]cross the continent, large dams are being planned with no understanding of how a changing climate will affect them - and little attention to the related problem of how dams will hurt river-based communities' ability to adapt to climatic changes. Governments and dam-lenders aren't taking the lead on these critically important issues.”
The article says:
To fill this gap, International Rivers commissioned an eminent hydrologist to examine the risks to dams in Africa's fourth largest river basin, which is slated for dozens of new large hydropower dams. His study warns that new and proposed dams on the Zambezi River are ill-prepared to withstand the shocks of a changing climate. The result could be uneconomic dams that under-perform in the face of more extreme drought, and more dangerous dams that have not been designed to handle increasingly damaging floods.
Dr. Richard Beilfuss, a hydrologist with 20 years' experience on the Zambezi River, evaluated the hydrological risks to hydropower dams in the basin.
Quoting Dr. Beilfuss the article says:
The Zambezi River will experience worse droughts and more extreme floods. Dams being proposed and built now will be negatively affected, yet energy planning in the basin is not addressing these huge hydrological uncertainties.
The report's key findings, as the article mentions, include:
• The basin is likely to experience significant reductions in rainfall, and higher evaporation rates in the next century. Because large reservoirs evaporate more water than natural rivers, big dams could worsen local water shortages (and reduce water available for hydropower).
• The designs for two of the most advanced dam projects are based on the now-outdated historical hydrological record, and have not been evaluated for hydrological risks. Under future climate scenarios, they are unlikely to deliver the expected services over their lifetimes, resulting in wasted investments.
• The occurrence of more frequent extreme floods threatens the stability and safe operation of large dams. If dams are "under-designed" for larger floods, the result could be serious safety risks to millions of people living in the basin.
• The Zambezi is already heavily dammed, and these projects have caused profound harm to livelihoods and biodiversity. The ecological goods and services provided by the river, which are key to helping societies adapt to climate change, are not being properly valued in planning for large dams in the basin.
"Ensuring energy and water security for the future will require new ways of thinking about river basin development," notes Dr. Beilfuss. "We must avoid investing billions of dollars into projects that could become white elephants."
Dr Beilfuss’ recommendations include incorporating climate change scenarios into dam design, to avoid the hazards of over- or under-designed infrastructure; big-picture for energy planning. "Planners need to carefully consider dams in the context of how climate change will shape water supply, and how future river flows must meet competing demands for power, conservation, and water for domestic use, agriculture, industry, and other services. A strategy aimed at empowering people to adapt to climate change must be central to these planning efforts." The report also recommends more diversified investments in energy supply projects to "avoid putting all eggs into one basket" in a time of increasing hydrological uncertainty – an especially critical step for Africa's most hydropower-dependent nations.
Dr Beilfuss calls for a full accounting of the values of ecosystem services supported by river flows, and changing dam design and operation to allow more natural flows to help restore ecosystem services on dammed rivers.
Lori Pottinger’s article says:
The situation on the Zambezi is hardly unique. On nearly every continent, […] large dams are at risk of becoming white elephants due to drought, and weapons of mass destruction during extreme floods.
The article concludes:
Africa cannot afford to take a head-in-the-sand approach to the climate risks of large dams. The time is now to prioritize climate-smart investments that explicitly factor in economic risk and the values of river systems.
Source:
[1] HuffPost, Sept. 21, 2012, http://www.huffingtonpost.com/lori-pottinger/a-risky-climate-for-big-d_b_1901065.html?utm_hp_ref=green
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