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Dam wrong
Written by Stan Kahn
The Phnom Penh Post. Thursday, 27 November 2008
http://www.phnompenhpost.com/index.php/2008112722909/National-news/Dam-wrong.html
Dear Editor,
Many dams are under construction, in the pipeline or proposed for
rivers in Cambodia, Vietnam and Laos that will have a dramatic impact
on Cambodia. While a case can be made for the relatively cheap, carbon-
negative power they produce, they are ultimately a mixed bag when all
factors are considered. In fact, large numbers of dams are slated for
removal in America over the impact they had on wildlife, supported by
the Endangered Species Act.
For example, several dams will be removed from the Klamath River that
passes through southern Oregon and northern California on its way to
the Pacific Ocean. Four dams were built about half a century ago that
have blocked the passage of salmon to their former spawning grounds.
Salmon are anadromous fish that spend most of their three-year
lifespan in the ocean but start and end their lives in small rivers
and streams, sometimes hundreds of miles from the ocean.
In one of the most fascinating and mysterious phenomenons of the
natural world, after roaming vast stretches of ocean for three years,
they return to spawn on or very close to the exact spot where they
were hatched. They grow as large as 40 kilograms and are one of the
tastiest fish one can eat. A healthy salmon run is capable of feeding
large numbers of people and thus should not be easily discounted.
The dam builders knew their work would sharply reduce salmon runs but
considered progress, in the form of cheap electricity, more important.
As the dams on the Klamath came up for licence renewal, the Endangered
Species Act kicked in and the owners were told they needed to adapt
them for fish passage if they wanted to continue to use them. When the
numbers were crunched, however, the cost was too high and economics
dictated that the preferred action was removal.
Cambodia is about to trade its abundance of fish, the primary source
of protein for 80 percent of its population, for electricity.
Cambodia's 25 percent per year increase in demand for electricity can
mostly be attributed to powering the new air-conditioned economy. So
that's the trade off: millions of fish for urban air-con.
Worse yet, the Mekong River Commission, which ostensibly would have a
role in protecting the river's environment, is too weak to demand
ecological considerations. It is possible to build small dams that
would minimise disruption of fisheries, but these are not the type of
dams being built.
Dams on the Mekong mainstream and its tributaries may lead to the
reduction, even possibly the end, of flooding on the Tonle Sap lake
with catastrophic consequences for the many Cambodians whose lives
depend on fish that feed on the nutrients brought by flooding.
An additional factor that is not being adequately considered is the
shortfall of water during the hot season when the electricity is most
needed. As I understand it, under current plans, some dammed rivers
will dry up completely during the hot season, obviously not the best
conditions for fish or any wildlife that depend on the river.
Other negative effects include the loss of fertile riverside land and
displacement of people, but the loss of fisheries is the most serious
consequence of the dam building.
The push for dam construction is so strong that I have little
confidence environmental damage assessments will make an iota of
difference to the authorities. It is too bad Cambodia could not learn
from others' mistakes.
Stan Kahn
Phnom Penh |
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