A stretch of the Chalakudy river that will be submerged; the rare Myristica swamps that will be completely submerged by the dam
What will be the loss due to this dam?
1. Loss of a unique ecosystem: The riparian vegetation (special vegetation along rivers) along the Chalakudy river system offers a unique ecosystem that there is no such ecosystem with such composition any where else in Kerala and even in the country. Further, it serves as a link between the varied habitats at lower and higher elevations.
2. Loss of several endemic species: The Athirappilly area has not yet been subject to any intensive studies and hence, the bio-diversity of the area is not completely documented. However, the occasional studies conducted by various agencies indicate a very high proportion of endemic species in the area. Even the short, inadequate Environmental Impact Assessment (EIA) conducted by WAPCOS (refer comments on EIA), shows that a large number of endemic species of plants(21.5%), butterflies(14%), fishes(23%), amphibians(53%), reptiles(21%), birds(12%), and mammals(14%) occur in the area. The report does not cover several species including those which are nocturnal. Even the endemic and threatened species such as the Travancore Flying Squirrel, Petinomys fuscocapillus fuscocapillus occurring in the area is not recorded.
3. Loss of high fish diversity and connectivity: The area is so rich in fish diversity, including endemic and endangered species, that the National Bureau of Fish Genetic Resources has recommended the area to be declared as a Fish Sanctuary. Five new species and 18 critically endangered species were recorded. Population of one species of fish found only in the Chalakudy River has reduced 99% during the last two decades. Construction of the dam prevents both upstream and downstream migration of some of the fishes which is a vital activity for their survival.
4. Unique area for bird conservation: i) All the four species of hornbills found in Kerala, namely Malabar Grey Hornbill, Grey Hornbill, Malabar Pied Hornbill, and Great Indian Hornbill occur in the Athirappilly – Vazhachal area; a very rare phenomenon. ii) 12 of the 16 species (75%) of the endemic species of birds seen in the Western Ghats are present in the Athirappilly - Vazhachal area. Recognising the high diversity in birds, BirdLife International (based in Cambridge), in a process of identifying important areas for bird conservation all over the world in 1995, identified the Vazhachal - Sholayar area as an Important Bird Area (IBA).
5. Loss of overall biodiversity: According to the Biodiversity Conservation Strategy and Action Plan for Kerala prepared by French Institute, Pondicherry, the conservation value of the Vazhachal (project area) is as high as 75%, (one of the highest!) which itself justifies the importance of the area for conservation. The total loss (both quantum and quality) of biodiversity in terms of species and population in the project and its impact area is not shown in the current EIA. Hence it is incomplete, especially keeping in view the Convention on Biological Diversity and The Biodiversity Act.
6. Loss of ecological functions and characters of the river system: Construction of the dam will completely alter the ecology of the river system, both upstream and downstream of the proposed dam site (from the dynamic and vital ecosystem to merely a physical water transporting system devoid of various ecological functions). One of the vital reasons for the high species richness and endemism of the area is the total volume of water flow and the fluctuation in it from a minimum of 7.26 cumec in May to 229.97 cumec in August (average of 50 years). Regulation of the flow to 6.2 cumec, as specified in the project proposal, will destroy the original ecosystem characteristics.
7. Impact on drinking water and agriculture downstream: (i) The 130 km Chalakudy river already has six dams. Four of them divert at least 40% flow to Tamil Nadu as part of the Inter State Parambikulam Aliyar Treaty. Water scarcity is already experienced in the downstream panchayats, and salinity intrusion is reported up to 20 km from the coast. Impacts of construction of an additional dam on these vital issues are not adequately analysed in the EIA report, as it confined its studies only up to 7 km from the project site. Its remarks on the impacts of the dam on downstream water uses, favouring the project, appear to be quite unscientific and superfluous. (ii) Impacts of the changes in the daily water flow consequent to the construction of dam on the biota and the hydrology itself; especially the latter related to drinking water are not brought out convincingly.
8. Impact on tribal population: The project will affect 22 tribal (Kadar) families living in Vazhachal settlement, just at the border of the submergible area and, the Tribal Cooperative Society, and Tribal Residential LP school, all within just 400 m downstream of the dam site.
Other Issues
Authenticity of the hydrological data used for the preparation of the project: One of the serious questions raised at the first public hearing held in 2002, was the authenticity of the hydrological data used by the KSEB in preparing the DPR (Detailed Project Report) which they had submitted to the honourable High Court. The WAPCOS while relying on the same data did not even try to clear these apprehensions.
Fallacy of conventional economic valuation
A unique biodiversity area is being sacrificed just for 163 MW of power to cope with the deficit in the peak loading period between 6 pm and 10 pm. Whether the economic returns from 163 MW of power after spending Rs. 385 crores (now revised to Rs. 650 crores) for constructing the dam, would commensurate the ecosystem services being rendered to us both by the forest in the project area and the Chalakudy river system? Traditional economic valuation followed by decision makers seems to show a logic deficit. The ecosystem services from this area would be in the order of Rs. 500 crores per year (Calculated as 3.5 times the global average of 145 crores per year (Nature Vol. 137)). In other words, if we do not disturb the ecosystem and allow them to remain as it is, we get services worth Rs. 500 crores in various forms such as water regulation, waste treatment, water supply, erosion control, raw material, food production and genetic resources. This should also be weighed with the average life span of the dam, which according to the KSEB is only 35 years.
Do we still need the Dam?
It may also be noted that while the proposal for the Athirappilly project, to generate 163 MW of power to cope with the deficit during peak loading from 6 pm to 10 pm, was framed sometime in 1995, Kerala had as many as 16 hydroelectric projects under different stages of construction; 14 of them started in the 1980s and, one each in 1976 and 1993. Nine of them have been completed since then yielding around 300 MW. More than what is expected off the Athirappilly project!
Can we mitigate the ecosystem loss/damages caused due to this project?
The sum total of the ecological impacts and consequences that may follow the construction of dam, creation of a reservoir, arresting the flow of water, submergence of a large tract of unique riparian vegetation is beyond our capability to mitigate. There is no technology for the same, leave aside the steps proposed in the project for mitigating the environment.