Kochi: The Kerala Water Authority(KWA), which supplies bulk of the piped drinking water in Kochi, is hoping that the water in Periyar river will not be filled with slush leading to high levels of turbidity in the water in the event of opening of the Idukki and Idamalayar dams. KWA had a bitter experience in 2013 and 2015 when slush filled the waters leading to high levels of turbidity following opening of the Idamalayar and Bhoothathankettu dams.
The Idukki district administration has stated that the shutters of Cheruthony Dam will be opened on Tuesday as part of a regulated release of the water in Idukki Dam. Water from Idamalayar Dam is also likely to be released as the water level has reached 166.14 metre at 3 pm on Sunday. The dam is having a maximum capacity of 169 metre, while water level at Idukki was at 2,394.28 ft at 6 pm as against the total storage capacity of 2,403 ft.
KWA is the main agency supplying piped drinking water to the residents of Kochi and their main source of water is river Periyar. A senior KWA official said that they don't have any system to prevent the slush from reaching the river waters in the event of the opening of the dam shutters. 'We can only hope that slush will not flood the waters", said the official.
According to him there is no possibility of taking any preventive measures in such a situation as nobody has any idea of the slush in the dams or how the water will gush into the river. In 2013 the supply was hit for many days as the turbidity level in the water caused by the slush hitting the pumping. In 2015 also KWA had reduced the pumping due to heavy rains and discharges from Bhoothathankettu Dam increasing the turbidity in the waters.
The high levels of turbidity and slush lead to more time for the purification of the water, said a KWA official. Normally it takes 2-3 hours for the purification of the water in storage tanks. But high levels of turbidity may require more time and leading to lesser quantity of water from the pumping station at Aluva. On average KWA the normal supply of water from the pumping station in Aluva is 240 million litre per day (MLD).
