The Water Resources Department (WRD) has proposed to construct a training wall at the mouth of the Cooum to prevent formation of sand bar. Work is expected to be taken up in three months after getting environment clearance.
The Cooum carried about 13,000 cusecs of water during recent heavy rain. The flow has dipped to about 8,500 cusecs.
Officials said heavy machinery were used to clear the sand deposited now at the mouth of the river and keep it open up to 120 metres. The river had minimal flow during the other months of the year. The flow was inadequate to minimise sand bar formation. The activities at the Chennai harbour led to sedimentation at a fast pace. The proposed training wall for 265 m on northern side and 310 m on the southern side was estimated to cost ₹70 crore.
A combination of boulders and concrete tetrapods had been planned for the construction of training wall. This would add more strength to the structure and allow tidal exchange, the officials said. The training wall was designed based on a study by the National Institute of Ocean Technology.
Free of obstructions
The project will help keep the mouth of the river open. It would allow free flow of water and prevent inundation in areas such as Arumbakkam and Aminjikarai due to sand bar formation. Work would be completed in 18 months.
The structure would be built without disturbing the groynes laid near the mouth and help in coastal protection, the officials added.
