Water Resources Department (WRD) will begin its share of cleaning the Adyar river from mid-February.
Though several encroachments along the river bank are yet to be removed, the WRD plans to kick-start the project in areas free from obstructions.
There are plans to float tenders by this month-end for taking up work to desilt the waterway in the 15-km stretch between Thirumudivakkam and the river mouth, officials of the WRD said.
At present, the river has a capacity to carry nearly 77,000 cubic feet per second (cusecs) of water. Once the desilting exercise is completed, the carrying capacity would increase by about 20%, officials said.
The department has submitted a ₹104-crore proposal to Chennai Rivers Restoration Trust as part of the Adyar River eco-restoration project.
The river is hardly 40 metres wide in some places and up to 400 metres wide near the mouth. “We are also planning to construct a retaining wall, in areas where the river width is narrow, including Jaffarkhanpet. This would ensure free flow of water,” an official said.
Instead of an earthen bund, the retaining wall would be built at vulnerable points for a stretch of 3km. The bund along other stretches of the river would be strengthened. Moreover, the department has planned to install shutters in the 20 inlets that bring water from stormwater drains to the river. This is to control the reverse flow during peak flood time, the official said.
A study may be initiated to find a solution to the problem of sand getting deposited at the Adyar river mouth. The WRD had already taken up improvement works in the portion of the river between Adanur and Thirumudivakkam at a cost of ₹19 crore.
On the opposition for a compound wall near Gandhi Nagar cricket ground, officials said arrangements are being made to provide vent near the bund to prevent water stagnation. Nearly 6,500 encroached structures are yet to be cleared along various stretches of the river, officials said.