Even as heavy rainfall batters the south-western ghat regions, dams and reservoirs in Kerala and Tamil Nadu are filling up fast. Five shutters of the Maniyar dam in Pathanamthitta were opened on Friday morning, following a rise in water levels. The district collector cautioned those living on the banks of the Pamba and Kakkad rivers. On Thursday, the Kerala State Disaster Management Authority (KSDMA) confirmed that nine dams have been opened, namely, Maniyar dam (Pathanamthitta), Kundala dam (Munnar), Malankara dam (Thodupuzha, Idukki), Peringalkuthu dam (Thrissur), Mangalam dam (Palakkad) and Kanjirapuzha dam (Palakkad), Kakkayam dam (Kozhikode), Kallarkutty dam (Idukki) and Pambla dam (Idukki). With the shutters of the Walayar dam opened on Friday, 10 dams in the state are now open.
In Karnataka too, flooding and landslides have affected many districts in the state. According to reports, at least nine have been killed in the flood-ravaged districts, and 1,24,291 people have been evacuated.
Meanwhile, on account of the heavy rainfall in the Cauvery, Tamil Nadu has received surplus water from the Kabini reservoir. According to reports, over 5,000 cusecs of water has been received at the Mettur dam as of Thursday even as water levels rose across smaller dams.
While half a dozen dams in Kerala are reaching full capacity and have few or all of their shutters open, dams in Tamil Nadu and Karnataka are not quite close to that level. However, they have experienced a rise in water levels given the heavy rainfall in the Cauvery catchment area of Kodagu.
What are the dam levels in Kerala?
As of Friday, Idukki dam reached 30% of its total capacity while the Idamalayar was at 37%. The Walayar dam in Palakkad district was at 201.64 metres, as against the Full Reservoir Level (FRL) of 203 metres; the Malampuzha dam is at 109.23 metres as against the FRL of 115.06 metre. While the three shutters of the Walayar have been opened at 2 cm, all spillway shutters, including the right and left bank canals, of the Malampuzha are shut. The Kanjirappuzha dam in Palakkad district is just shy of full capacity at 97.41 metres, against 97.535 metre FRLâ€” all spillway shutters of the dam have been opened at 100 cm. Similarly close to capacity is the Mangalam dam over the Cherukunnapuzha river which is at 77.85 metres against full level of 77.88 metresâ€” all six shutters of the dam have been opened by 50 cm. Four shutters of the Maniyar barrage too have been opened with water level at 34.4 metres against 34.62 metres.
Speaking to TNM during the deluge in Kerala last year, experts had explained that spillways are comparable to pressure cooker valves. This means that they allow the release of water in a controlled and safe manner when they are opened. Nine districts in the state have been issued with a red warning whilve over 25,000 people have been shifted to relief camps.
What are the dam levels in Karnataka?
As of Friday, the Almatti dam in North Karnataka stood at 517.10 metres as opposed to full reservoir capacity at 519.60 metres with inflow at 4,30,000 cusecs from the Krishna river. Narayanpur dam in Bijapur district was receiving an inflow of 4,37,740 cusecs while the dam itself was at 487.88 metres. On the Cauvery, the Krishnarajasagara dam was at a storage capacity of 45.05 metres as against its capacity at 124.80 feet. The Tungabhadra dam was at 100.86 tmc while its FRL is 1633 feet above mean sea level.
Coastal Karnataka has been experiencing severe landslides amid rainfall in the region. Udupi, Shivamogga and Kodagu districts and Malnad region of the state have been affected by the flooding.
What are the dam levels in Tamil Nadu?
As far as Tamil Nadu is concerned, the Tamil Nadu State Disaster Management Authority (TNSDMA) figures state that the Periyar dam is at 123.20 feet as against the full capacity of 152 feet, the Krishnagiri dam is at 30.60 feet against 52 feet of full reservoir level. The Sholayar dam in Coimbatore district, whose full capacity is 160 feet is now at 133.45 feet. The discharge to the Cauvery from the Bhavani river has been 335 cusecs as of Friday.
Members of the State Disaster Response Force (SDRF) have been instructed to move to Nilgiris district where the Avalanche region received record rainfall on Thursday, measuring 820 mm of rain.