The civic administration seems to be leaving no stone unturned to suppress frothing at Bellandur and Varthur lakes. Nearly a month after the siphoning technology failed at the two lakes, the civic administration is now placing coir blocks at the waste weirs to reduce the turbulence of water and frothing.
While residents agree that frothing at the weirs had ceased, they criticised the intervention as a “band-aid solution”.
The coir blocks have been placed on a pilot basis at two weirs — Yemalur weir of Bellandur lake and Varthur Kodi of Varthur lake.
The pilot has been implemented by B.V. Subba Rao, Centre for Climate Change, Engineering Staff College of India, Hyderabad.
Mr. Rao told The Hindu that the blocks will reduce the velocity and turbulence of water reducing froth and also act as filters adsorbing large pollutants. “This is the first time that coir has been deployed at lakes in the country,” he said.
Y. Joel Sumanth, project manager, ESCI, said that the results were encouraging. “Frothing has reduced by over 90% at the Varthur lake weir and by nearly 80% at the Yemalur weir of Bellandur lake,” he claimed.
P.N. Naik, member, engineering, BDA, said that they were studying the results of the pilot and would expand it to other weirs as well soon.
Mr. Rao has also recommended putting up foam nets horizontally above the canals to prevent air disbursal of foam. “In the long term the only way to solve the issue is to clean up the kaluves leading to the lake,” he said.
However residents are skeptical. “We need to see how the coir blocks can sustain heavy rains. The monsoon has only just begun and it is yet to be seen how the coir blocks withstand increased water flow without getting washed away, like the siphon pipes” said Jagadish Reddy of Varthur Rising.
