The gates of Chembarambakkam reservoir were opened Wednesday for the first time in five years as a precautionary measure, releasing a torrent of surplus water into the Adyar river here after its storage was just 20 per cent short of its capacity due to heavy rainsahead of an incoming cyclone, officials said.
About 1,000 cusecs (cubic feet per second) of water was released from the dam, a major source for the city's water requirements, into the river that flows through the metropolis before draining into the Bay of Bengal.
The decision to open the shutters of sprawling dam was taken as its storage level touched 3,000 million cubic feet against its full capacity of 3,645 Mcft amid forecast of heavy rains in the next two days under the influence of the severe cyclone 'Nivar' set to cross the coast before dawn on Thursday.
As the surplus waters gushed forth with the opening of shutters after about five years, Chief Minister K Palaniswami inspected the dam premises and reviewed the precautionary measures and the outflow. Palaniswami said he advised the officials to "carry out their work cautiously and without causing any inconvenience to the people."
On the dam's water level, the Chief Minister told reporters that it has reached 21.5 feet as against its maximum of 24 feet. "The reservoir is receiving about 4,000 cusecs and from noon 1,000 cusecs is being released," he said adding surplus water of about 2,000 cusecs from Aadhanur lake in the suburbs was also being let into the Adyar River.
"The Adyar River could carry up to 60,000 cusecs and people need not have any apprehensions. All precautions have been taken," he said and pointed out that approximately, only 6,000 cusecs now flowed in the river.
The delayed opening of the reservoir in 2015 after very heavy rains was seen as a trigger for the devastating floods that hit the city then, though the government had rejected it. A flood control official of the Public Works Department said the water level was close to 22 feet as against the maximum of 24 feet.
As per norms, inflows from now onwards should be released 'as it is' and it would be done in a phased manner, the official said. The storage has increased in view of inflows from the Krishna River coupled with the monsoon rains and the current inflow stood at 4,027 cusecs, he said in a communique.
An alert, already sent by the PWD to local authorities said, "the outflow will be increased step by step based on the inflows." The Chembarambakkam reservoir, among the four very important drinking water sources to Chennai, is spread across 25.51 square kilometers and is located in Kancheepuram district's Kundrathur taluk. Poondi, Cholavaram and Red Hills are the other reservoirs.
The Adyar River empties into the sea, traversing city localities like Kotturpuram and suburban neighbourhoods including Sirugalathur and Kundrathur. People, who gathered eagerly to witness the water release along the river bank were advised by the authorities to move away considering their safety while intermittent rains lashed the city and suburbs.
The Greater Chennai Corporation said it has cleaned up the Adyar creek besides other canals and lakes like Mambalam and Velachery respectively. The GCC said it has already advised people living close to the river like those in Jafferkhanpet to move to its shelters adding "169 shelters are open and ready."
For assistance, people may contact them at 044-25384530 and 044-25384540, the GCC said. Palaniswami said all precautionary measures have been taken in view of the cyclone and so far 400 people have been accommodated here in relief shelters here.
Waterlogging has been reported from 30 low lying areas and GCC has deployed heavy-duty motor pumps to drain the rain water, he said.
Also, electricity poles that were affected in city localities have been set right immediately by electricity corporation personnel, he said and appreciated government employees for their work. City police said 12 teams, led by sub-inspectors of Armed Reserve, with necessary equipment and boats have been deployed for relief work.
Police appealed to the people to seek their assistance, if needed by contacting the temporary control room at 9498181239. As many as 38 uprooted trees were removed by them with the assistance of GCC and disaster relief workers, they said.