and environmental impact of raising the water level
The Kerala Government has obtained an expert committee
report on the ecological impact of raising the water level in the
Mullaperiyar dam above 136 feet. Ecological
Impact Assessment of Water Level Increase at Mullapperiyar Dam,
Kerala is aimed at buttressing the argument of the State
Government against raising of the reservoir level beyond 136 feet
as demanded by Tamil Nadu. But it may prove counter productive for
The Supreme Court has already rejected the argument of the State
that the raising of the water level would cause much environmental
harm to the Periyar Tiger Reserve. The study, on its part, does
present additional data to further the argument. However,
sufficient material is lacking in support several of the
conclusions of the study. Some are erroneous.
The irony is that the conclusions could go against the State’s own
proposal for construction of a new dam—the work on a new dam would
be causing much more disturbances to the environment than raising
the water level. Pursuance of the environmental angle against
raising of the water level to the extreme by the State may also
give the impression that its main argument-- that the dam is weak
and unsafe, is somehow not strong. Loss of life and property
should be of bigger concern than limited environmental impact of
raising the water level.
The expert Committee that did the study was headed by Dr.
Dhrubajyoti Ghosh, Regional Vice Chairman (South Asia), Commission
on Ecosystem Management, IUCN and senior Fellow (Development
Studies) of Centre for Studies in Social Sciences, Calcutta.
The members were Dr. H. S. A. Yahya, Professor, Department of
Wildlife Sciences, Aligarh Muslim University and Mr. Saroj Kumar
Patnaik, former Additional Principal Conservator of Forests,
The Committee itself admits that it did not get enough time for a
detailed assessment. Naturally, some of its recommendations sound
The committee states, in its first recommendation, that the
ecological impact of a dam failure will be catastrophic. But, it
marshals no supporting material. Of course, the reservoir itself
will be lost and it can be assumed that the otters in it would
lose their habitat! (The loss of human lives and economic loss to
both in Tamil Nadu and Kerala will be very high. However, that is
not strictly within the purview of the assessment).
The study says that the increase in water level will hit the
critical grasslands of the Periyar ecosystem and could severely
endanger the food chain of the endangered tiger. The grasslands
referred to here are the ones that came up following lowering of
the reservoir level in 1979, and so, that part of the ecosystem is
only about three decades old.
Tigers and deers have existed here for centuries and there is
little to prove that the deer, which is a rainforest species, is
dependent on the grasslands.
The Committee draws attention to the signs of distress and fear
visible amongst the tribes and children of settlers on the banks
of the reservoir. It seems to have confused between the signs of
distress and fear reported from among the people living downstream
of the spillway over possible dam failure and concerns of those
who have encroached upon the banks. The latter are legally
evictable settlers as Government policy only supports
regularisation of pre-1977 settlements. However, as the committee
points out, there is the risk that the evictees would go back into
the forest and exploit the ecosystem.
The committee also recommends that all engineering efforts to
raise the water level should be put on hold. It appears that the
committee is under the impression that engineering works,
requiring movement of men and machinery, are needed to increase
the water level. All that is required now at Mullapperiyar to
raise the water level is the lowering of the spillway shutters.
The committee points out that raising of the water level and
diversion of additional quantities of water out of the Periyar
Wildlife Sanctuary would require permission of the Chief Wildlife
Warden following notification of the new rules under Wildlife Act
in 1993. However, the moot question is whether the rights granted
to Tamil Nadu as per the Periyar lease deed on waters falling in
8000 acres had been extinguished at the time of notification of
the sanctuary. Tamil Nadu is not seeking any additional quantities
of water than granted to it under the more than a century old