The long-running project to prevent sedimentation at the mouth of Ennore Creek could start in a few months.
The Water Resources Department (WRD) is expected to start construction of a formation wall for the sustainable opening of the mouth of Ennore Stream in March or April. The project aims to reduce sedimentation and flooding in areas upstream of the Kosasthalaiyar River.
WRD officials said the state Coastal Zone Management Authority’s expert review committee cleared the Coastal Regulatory Area and recently recommended the project to the Ministry of Environment, Forestry and of the Union’s Climate Change for final approval.
The department planned to build “straight practice walls” for a length of 500 meters on the north side of the embankment and for a length of 400 meters on the south side near the Ennore stream where Kosasthalaiyar joins it.
How will the walls help?
Formation walls at the creek level would help direct the flow of the river and also interrupt the transport of sand by the waves. Officials said that at present minimal dredging is being carried out to keep the mouth of Ennore Creek open to a width of 80 meters to allow for tidal action and minimize the formation of sandbanks.
It is planned to use a combination of boulders and tetrapods to construct the practice wall to allow the mouth of Ennore Stream to be opened up to a width of up to 400 metres. This would mitigate flooding in upstream areas including the new town of Manali, around the banks of Kosasthalaiyar and help drain flood waters from the maximum capacity of the river.
Last year, nearly 31,000 cubic feet per second (cusecs) of floodwater poured into the sea during the northeast monsoon. The Kosasthalaiyar has a maximum flood discharge capacity of more than 1 lakh cusecs near the creek, officials said.
The formation wall would also provide better access for fishing boats and contribute to the livelihood of the inhabitants of the surrounding fishing hamlets. Once final approval is provided, work on the ₹128 crore project would be implemented with funding from Kamarajar Port Limited.
The demolition of the old piers near Nettukuppam would also be resumed as part of the project. The work should be completed within a year, an official added.