“Water has become expensive, and it will be even more expensive in the
future, which will make it the ‘blue gold’ of the 21st century”. Ricardo Petrella,
“For every claim to virtue made by the proponents of big dams, there is
a clear-cut, factual and demonstrable refutation”. Elmer Peterson, Big Dam Foolishness,
“In my view, nature is awful and what you do is cure it”. Camille Dagenais,
Canadian dam engineering firm SNC, 1985
To The Friends of The Mekong
and VN2020 Mekong Group
FOREWORD: This is the last of a three-article series entitled “Mekong -
A Look into the Next Half Century” dealing with the future of the Mekong Delta.
The first article sketched a general overview of the issue and offered
these observations: hydroelectricity still remains the least costly source of
power to meet the needs of economic development. Consequently, the exploitation
of hydro-power on the Mekong is an irreversible process that will move ahead
regardless of oppositions that may be raised along the way. What is needed now
is a macroscopic plan to neutralize the cumulative impacts caused by climate
change and the hydroelectric dams built upstream.
The second article entitled “The Multi-purpose Sea Dyke / MSD” proposed
a bold project primarily geared to prevent seawater from intruding into the
basin and save the Mekong Delta from being submerged should the sea level rise
by 1 meter in the wake of global warming in a not-so-far future. Other added
benefits to be derived from this project included: water reservoirs, land reclamation,
improvement of the transportation networks, and higher standards of living for
the basin’s inhabitants. (3)
This third article advocates the construction of fresh water reservoirs
in the natural depressions of the Đồng Tháp Mười and Cà Mau swamplands in order
to store the annual rainfall as well as the water coming down from upstream
the rivers. By doing so, we will no longer watch all that water flow wastefully
through the estuaries into the East Sea. On the other hand, we can use the water
thus saved to meet the immediate drinking water, cultivation and industrial
needs of the 20 million inhabitants of the Mekong Delta. More importantly, we
will be able to preserve the underground aquifers so that they can continue
to wash away the alum that causes the acidification of the entire farm lands
in the region.
All the three above articles in the trilogy named “Mekong- A Look into
the Next Half Century” are conceptual in nature. They offer a tentative picture
of a future several decades down the road and the readers are encouraged to
look at them as a collection of open-ended information that will be complemented
and updated by interested parties as Mother Nature and humankind evolve with
time. At the moment of this writing, in 2011, it is beyond the ability of the
writer to fully visualize what that future would hold for us.
A case in point: in the first article, it was mentioned that should the
sea level rise by 1 meter, 90% of the Mekong Delta’s area would be covered by
seawater (2). However, Mr. Trần Thức, the Director of Vietnam’s Institute of
Climatology, Hydrology, and Environment predicted that “In the event the sea
level registers a one-meter increase then the entire Mekong Delta – that is
100% of it – will be submerged”. On the other hand, based on their own research
on the topography of the region, MM Ngô Minh Triết and Phạm Phan Long suggested
a more conservative estimate: “Should the sea level rise by one meter, 50% of
the Mekong Delta would go under the water and an additional 25% would turn into
storm surge zone”.
To conserve the Mekong Delta requires that we embark on a protracted journey.
The works done by this writer can be compared to a “drop of water” in the open
sea, a small contribution to the intellectual wealth of our people. To survive
on this land of destiny, our people have to constantly struggle against the
threat of invasion from the North and the increasingly unforgiving elements
from Mother Nature.
THE GEOGRAPHY AND DEMOGRAPHY OF THE MEKONG DELTA
Out of the seventeen estuaries of the Mekong, seven of them are tributaries
of the Tiền and Hậu Rivers. It is through these very waterways that seawater
intrudes into the basin. In 2010, it reached as far as 128 kilometers inland.
According to an estimate by the Institute for Hydrological Planning in the South
[Vietnam], the basin’s fields are covered by as much as 1.5 billion cubic meters
of seawater during the dry season per day. This figure can grow to more than
25% higher during the rising tide (7).
After 1975, dikes were built around the estuaries to ward off salinization.
Unfortunately, they proved to be only temporary measures because once the sea
level starts on a sustained rise, both the areas bordering the river mouths
and the entire basin will become inundated by seawater. Therefore, a mega project
to construct a multi-purpose sea dyke must embody a strategic approach offering
long-term solutions to the problems.
It is interesting to recall an anecdote that took place between Peter White,
the reporter of the National Geographic, and the Vietnamese Minister of Information,
Mr. Tôn Thất Thiện in 1968. Let us read what Mr. White had to say about it:
“First I studied the maps. Then a U.S. Army plane carried me high and low
over all the likely place, where muddy beaches and mangroves swamps meet the
South China Sea. I did my best, but I could only find eight dragons. Yet how
could that be, when the Vietnamese call the Mekong River the Cửu Long Giang
– the River of the Nine Dragons?... I consulted my friend Tôn Thất Thiện, long
a mentor on matters Vietnamese. Now he was Minister of Information in Saigon.
He smiled. “There really are only eight,” he said. “But eight is not a lucky
number. It has to be seven or nine. So we had to find another one, and we did.
But it is very small, very narrow, and less than 10 miles long. I hope you are
not too unhappy to have missed it.” (8)
THE TWO DEPRESSIONS IN THE ĐỒNG THÁP MƯỜI AND CÀ MAU PLAINS
In addition to the water reservoirs to be built along the future 600-kilometer
long Multi-Purpose Sea Dyke (MSD) (3), there are two natural depressions in
the Mekong Delta that are presently serving as natural reservoirs storing the
rain water of the Rainy Season. The Tonle Sap is the only river in Cambodia
that cyclically reverses its course depending on the Dry or Rainy Season. For
that very reason, the Tonle Sap’s area can undergo drastic changes during the
year: In the Dry Season, it measures about 2,500 km2. Nevertheless, when the
Rainy Season comes (from May to September), the water level in the Mekong surges
dramatically creating tremendous pressure forcing the Tonle Sap River to reverse
its course and flow into the Tonle Sap Lake. As a result, the water in the lake
rises from 8 to 10 meters and overflows its bank causing its area to grow fivefold
to about 12,000 km2. The forests around the Tonle Sap Lake become flooded and
are turned into a giant breeding ground for the fish population that accounts
for approximately 60% of Cambodia’s fish supply. At the end of the Rainy Season,
around November, the Tonle Sap reverts to its normal course and it is the time
to celebrate the Water
Figure 1: Salinity intrusion 1996-2010
Festival or Bon Om Tuk. At the Quatre Bras, the meeting place of four river
tributaries, the fish migrating down from the Tonle Sap Lake will either follow
the Lower Mekong to go into in the Tiền River or stay their course on the Bassac
River to enter the Hậu River. In both cases, those migratory fish end up into
either the ĐồngTháp Mười or Cà Mau natural depressions. There, they multiply
rapidly providing a plentiful supply of food source to the inhabitants of the
While the offshore construction of the MSD does not necessitate a costly outlay
to pay for land acquisition, it is a different story with the building of the
two fresh water reservoirs in the basin. The need to displace then relocate
the local people would prove a challenging hurdle at first. Hopefully, if they
are treated fairly and remunerated equitably for their losses, it would be possible
to obtain their consent and cooperation. It is all for the good of the Mekong
Delta and the future generations.
We need a policy marked with transparency and aimed to serve the common good.
Once that condition is met, it would not be too hard to convince the inhabitants
of the Mekong Delta who nurture a deep love for their land to make the needed
sacrifice to ensure a stable future for all.