The Water Resources Department (WRD) will take up projects worth ₹184.22 crore in southern parts of the city around Pallikaranai marshland to construct new channels and also bridge gaps between waterbodies and the marshland.
These projects would be implemented as emergency works to provide the much-needed respite to areas such as Semmencheri and Pallikaranai that face the threat of flooding every monsoon. Officials of the WRD said several areas remained under sheets of water during the Northeast monsoon.
The department has been directed to call for tenders for the projects announced in the Assembly recently as three months of work period is usually lost between government order and administrative sanction. This often led to break in works after the onset of the monsoon and spilt over to the next fiscal and issues related to escalation of project cost. This time, the tenders would be called for during the waiting period for the government order. However, bids would be opened only after receiving the order, they said.
Officials noted surplus water from several groups of waterbodies drained into the Pallikaranai marshland. However, areas, including Perumbakkam and Semmencheri were flooded as there was no defined route for the surplus water to join the marshland after DLF, due to rapid urbanisation.
The department plans to provide a network of water channels to bridge the missing links between Ottiyambakkam channel and Madurapakkam drain and up to Pallikaranai swamp in Semmencheri and Perumbakkam.
For instance, a channel would be constructed from Madurapakkam Odai to the existing channel on the northern side of DLF and also build a retaining wall along the channel in Sholinganallur at a cost of ₹24 crore. Similarly, the missing links from Madurapakkam Odai to the marshland would be bridged with a network of macro drains from the Odai in DLF Campus road for a distance of 500 metres. There are also plans to improve Okkiyam Maduvu till Buckingham canal in Sholinganallur and link channel between Adambakkam tank and Veerangal Odai.
It took five or six days for the waterlogging to be reduced last year. The department plans to construct concrete channels for quicker draining of surplus water into the marshland. A two-km-long channel would be built from Arasankazhani Velanthangal tank to the marsh.
More channels are proposed to be constructed to cover the missing link between tanks in Ottiyambakkam and Arasankazhani and the marsh. The department plans to improve the flood mitigation infrastructure within a year, the officials said.