KOCHI: The Kerala State Electricity Board (KSEB) has submitted a proposal to the state government to construct a new dam at Peringalkuthu, located under Vazhachal forest division, which, according to the board, will save the Chalakudy river basin.
The water level in the Chalakudy river had risen by 16 ft on August 16, 2018, inundating most parts of Chalakudy town. Even two-storeyed houses on the banks of the river submerged following the release of water from Thunakadavu, Parambikulam, Upper Sholayar, Lower Sholayar and Peringalkuthu dams located upstream.
According to the KSEB, Peringalkuthu is a small dam with a storage capacity of only 32 million cubic metre (MCM), while the upstream dams are huge. The Upper Sholayar Dam located in Tamil Nadu has a storage capacity of 153 MCM, while Lower Sholayar also has a similar storage capacity. The Parambikkulam dam, constructed in 1967, has a storage capacity of 505 MCM, while the maximum storage of Thoonakkadavu is 15 MCM. If the flood gates of these four dams are opened, the Peringalkuthu dam will start overflowing within two hours.
“The situation is like trying to contain the water flowing from a big container with a teacup” KSEB chairman NS Pillai told ‘Express.
“The design of the dams upstream Peringalkuthu is unscientific. If there is heavy inflow from the upstream dams, Peringalkuthu will start overflowing within two hours and it will lead to a situation similar to the 2018 mid-August flood and Chalakudy will be inundated within three hours. The only way to ensure protection of life and property of people living in Chalakudy is to build a new dam,” said Pillai.
However, the task is easier said than done. It is sure the green activists will raise a hue and cry if the government approves the proposal as it will submerge more than 500 hectares of deciduous and evergreen forests, which is home to hornbills, elephants and over 200 animal species.
The KSEB, while constructing the Peringalkuthu dam, had plans to build a right bank dam with a capacity of 200 MCM. However, the project was shelved anticipating protest. To get sanction for the dam, the government will have to obtain clearance from the Forest Department and the Ministry of Environment and Forest, which will be a Herculean task. However, the board is trying to highlight the vulnerability of Chalakudy due to the presence of big dams located upstream.
The discharge capacity of Parambikulam is 1,639 cubic metre per second, while that of Sholayar dam is 1,739 cubic metre. Thoonakadavu has a discharge capacity of 456 cubic metre. If these three dams are opened, the quantity of water reaching Peringalkuthu will be 3,882 cubic metre per second. The discharge capacity of Peringalkuthu is only 2,265 cubic metre per second and the dam will start overflowing within two hours. The Central Water Commission has highlighted this situation in its report about the Kerala flood, said a senior KSEB officer.
The flood water was flowing 2.5 m above the dam top road for 26 hours from 4.30 am on August 16 to 7 am on August 17, 2018, which caused extensive damage to the dam and its power house. By 9 am on August 16, most parts of Chalakudy town were inundated.
“Restrictions have been imposed on de-reservation of forests or use of forest land for non-forest purpose under the Forest Conservation Act, 1980. But we have to think what happened to the Athirappilly project and Anakkayam project which were given clearance by the Forest Department. The 163 MW Athirappilly project was accorded sanction and the 54 MW Anakkayam project was cleared in 2014. While we all agree that steps should be taken to protect the life of people living downstream, we have to consider the environment factor also. It is for the government to take a call,” said Vazhachal DFO S V Vinod.