Posted on August 8, 2017
By K. Lakshmi, The Hindu
The long-pending project to dredge the four major reservoirs, which act as a lifeline for the city’s water supply, will be taken up in September and October.
The combined storage at the reservoirs at Poondi, Cholavaram, Red Hills and Chembarambakkam has touched its lowest and is at a mere 98 mcft, against the total capacity of 11,057 mcft.
The lakes are parched after nearly 13 years, pushing the city into a severe water crisis. While it means scouting for alternate sources to bridge the gap in supply, experts note that this is the best time to remove silt accumulated in the lakes and build the storage.
According to officials of the Water Resources Department, which maintains the lakes, the project to desilt the reservoirs is in the final stages of approval. The work would start in September or October. Though works had been carried out to improve the water bodies, including strengthening of bund, no major project has been devised to desilt the lakes for many years now. As per the WRD records, Poondi reservoir was the last to be added among the reservoirs and created for storing drinking water for the city. While Chembarambakkam reservoir existed from the Pallava period, the other reservoirs were created around 1876-77.
Soil tests
Officials said tests would be done to ascertain soil strata and how much soil can be dredged from the lakes spread over a total area of nearly 21,400 acres. “We plan to remove silt up to five feet till the impervious layer of soil. We expect to boost the storage in the lakes by at least 1,500 mcft once the desilting exercise is completed,” said an official.
The three-year project would be carried out at intervals as the water level would build up during monsoon. “The ?40-crore project aims to remove nearly six crore cubic metre of silt from the lakes. The sale of savudu soil is expected to bring ?600 crore in revenue to the government,” said an official.
