Climate change is likely to be the one phenomenon that will have the most serious implications for dams in theHimalayas.
Most dams are designed based on historical data of river flows, with the assumption that the pattern of flows, have effectively been destroyed this assumption.Extreme precipitation events like glaciers and other phenomenon can lead to large floods.The safety of dams in view of the increased flows/floods is a major cause of concern.Even if a dam is able to survive higher flows, bigger floods are likely to lead to higher backwaters, increasing the areas affected by submergence.
One of the Example is Dig Tsho Glacial Lake Outburst Flood, Nepal.
In 2007, the Affected Citizens of Teesta staged a relay hunger strike against the projects for more than 500 days. Photo: Affected Citizens of Teesta (ACT)
All of these things point to the need for a comprehensivereview of the dam building program in each of the riverbasins in the Himalayas.
THE HIMALAYAN REGION
REVIEW OF REPORT ON DAM
BUILDING IN THE HIMALAYAN
• The Himalayas are the mountain ranges that separate
the Indian sub-continent from the Tibetan Plateau.
• It includes the Karakoram, the Hindu Kush, and a host
of minor ranges extending from the Pamir Knot.1
• The Himalayas range from the Indus River Valley to the
Brahmaputra River Valley, they form an arc 2,400
kilometres long, which varies in width from 400 km in
the western Kashmir-Xinjiang region to 150 km in the
eastern Tibet-Arunachal Pradesh region.
• The Himalayas stretch across six countries:
Bhutan, Nepal, India, Pakistan, China and Afghanistan.
• It is the source of some of the largest rivers in Asia –
the Indus, Ganga, Brahmaputra, and Irrawaddy. Glacial
and snow melt is an important source of the flows of
• The rivers provide sustenance, livelihoods and
prosperity to millions of people living in a vast area
that stretches from the Indus Basin plains of Pakistan in
the west to Bangladesh in the east.
• Himalayan rivers have large potential to generate
hydroelectric power. Eg- the Bhakra Nangal project in
India and the Tarbela project in Pakistan.
Social and Environmental
• ECOLOGICAL IMPACTS
The Himalayas are recognized not only as a hotspot of biodiversity
but also for their fragility. Conservation International96 lists the
Himalayas among the biodiversity hotspots of the world and says
that Conservation International also says that of the estimated
10,000 species of plants in the Himalayas, about 3,160 are
endemic, as are 71 genera. Furthermore, five plant families are
endemic to the region.98 About 300 mammal species have been
recorded in the Himalayas, including a dozen that are endemic
GREEN HOUSE GAS EMISSION
Hydropower is often portrayed as an important weapon
in the fight against climate change, claiming that it
produces very small amounts of greenhouse gas (GHG)
• Brazil’s National Institute for Space Research (INPE)
• show that the methane emissions from Indian big
• contribute 18.7% of the total GHG emissions in
Implications of climatic change on dams
• An increase in the intensity of precipitation, leading to
higher flows and floods
• An increase in glacial and snow melt leading to an initial
increase in river flows and floods
• Subsequent disappearance or significant depletion of glaciers
and snow leading to depleted flows
• Change in the seasonal distribution of total flows
Implications of Climate Change for Dam Safety
• Most dams are designed based on historical data of river
flows have effectively been destroyed.
• Extreme precipitation events like glaciers can lead to large
• The safety of dams in view of the increased flows/floods is a
major cause of concern.
• Bigger floods are likely to lead to higher backwaters if a dam
is survived, increasing the areas affected by submergence.
• Another cause for concern is the potential increase in
the sedimentation in the rivers due to climate change.
Responses of Civil Society and
Affected People’s Groups
Protest against the Teesta Dams in Sikkim, India, 2007
• Combinations of demand-side management
• Efficiency in generation, supply, transmission and energy use
• Renewable sources of energy are at the core of most of these
Meeting to discuss the potential impacts of the planned West Seti
Hydropower Project, in Nepal, 2007. It is estimated that 15,000
people will be adversely affected by this project. Photo: Yuki
• The Himalayas store vast amounts of water, and with their high
slopes, the fast-moving rivers present huge potential for
• Projects are likely to have huge social, environmental and cultural
impacts, impacts that will be especially harsh on locals, tribal
people, farmers and others living in the remote valleys of the
• These projects threaten not only livelihoods but often the very
identity and culture of these people.
• The downstream impacts of the proposed projects will also be
• India, Pakistan, Nepal and Bhutan have initiated massive plans to
build several hundred dams to realize this potential.