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Presenter: Patrick McCully, International Rivers, USA.Temacapulín, Mexico - October 2, 2010
Citation preview
Bringing an End to the
Big Dam Era
Patrick McCully
Temacapulín
October 2010
The Damming of the World
Rate of Large Dam Construction
0
1000
2000
3000
4000
5000
6000
<1900 1910s 1930s 1950s 1970s 1990s
Number of Dams
Source: ICOLD World Register of Dams 1998 (Includes only “registered dams”;excludes most dams in China)
Status of rivers• 50,000 large dams/diversions
moderately/severely impact 60% rivers
• > 500,000 km altered for navigation
• 90% sewage in developing countries untreated
• Half world’s wetlands destroyed
• Watershed degradation, climate change disrupting flows
Status of freshwater biodiversity
• Rivers, floodplains, lakes & wetlands impacted more than any other ecosystem type
• Freshwater species populations halved 1970-2000
• 20% freshwater fish species threatened, endangered or extinct
• N. America: 123 species of fish, molluscs, crayfish, amphibians extinct during 20th century
Social impacts• 40-80 million people physically displaced• 472 million suffer livelihood losses
downstream• Spread of waterborne disease• Induced flooding, earthquakes• Repression of opponents
Unmet needs• >1.1 billion without access to
adequate, clean water– 2.4 billion without access to
sanitation– Waterborne diseases kill 14-
30,000 people/day• 1 billion people
undernourished• 60 million people suffer from
damaging floods• 2 billion people lack access
to modern energy
Justifications• Power and water to the
unserved• Increasing food
production• Alleviating poverty,
promoting development
• Reducing greenhouse gas emissions
• Climate change adaptation
Big dams irrelevant to the unserved and hungry
• 80% of unserved, and hungry, in rural areas• Key to meeting unserved are decentralized,
community-based, low-cost options e.g. water harvesting, low/no-water sanitation, small-scale renewables
Hydro vs New Renewables
05
10152025303540
1997199819992000200120022003200420052006200720082009
GW
Large HydroSmall hydroWindSolar(PV/CSP)
Dams & Climate Change• Emissions of greenhouse gases • Hydro emissions vs. fossil fuels:
– Run-of-river hydro very low– Temperate reservoirs low– Large tropical reservoirs high
• Reduced generation: drought and evaporation– Hydro ≥50% supply in 63 countries
• Safety threatened by extreme floods • Faster sedimentation• Worsen climate change biodiversity
impacts
Current trends• Increased funding for clean energy, retrofitting existing projects,
river restoration, rainwater harvesting• New “enlightened” generation of water “experts”• Declining importance of ‘traditional’ dam funders• Continuing strong movement for water justice
BUT• Emergence of China as major global dam funder• Brazil, India gaining in importance• Continued World Bank promotion of big dams/diversions• Governments promoting new water megaprojects
– Megahydro in NE India, SW China, Amazon, Congo– Megadiversions in India, China, Brazil
Slide from presentation by John Briscoe, World Bank Senior Water Advisor, 2005
20th Century Water Ethos• Forecast ever increasing
demand, build new supply • Water flowing to sea is wasted• Water should be moved from
surplus to deficit areas• Floods should be eradicated• Engineering is excellent,
bigger is better, costlier is cooler
21st Century Water Ethos?• Respect natural cycles and limits• Manage demand, minimize withdrawals• Democratic planning • Recognize vital role of
rainwater• Promote small,
decentralized technologies• Prioritize equity,
sustainability• No-regrets planning for
climate change adaptation
The End/El Fin
www.internationalrivers.org