The Water Resources Department (WRD) is planning to approach IIT-Madras and Anna University for technical support for a project to construct groynes — a collection of boulders laid perpendicular to the shoreline, at regular intervals — between Ennore and Ernavoorkuppam.

The groynes will help protect the shoreline, prevent the incursion of seawater into fishing hamlets and help reclaim the shoreline.

The project envisages 10 groynes at a cost of Rs. 31.82 crore, and was announced in the assembly budget early this year. The WRD has proposed to seek the support of experts from IIT-Madras to design the project, which will cover nearly four km. This will comprise details on the location, length and behaviour of waves and sedimentation.

According to sources, a nearly 100-metre width of beach has been eroded near Royapuram over the past three decades. The impact of the erosion has been felt up to six km north of Chennai harbour, since the late 1970s.

The project will benefit residents of nine hamlets, including Kasikoilkuppam, Chinnakuppam and Netaji Nagar. The hamlets have a total population of about 7,000 and they face a severe threat of erosion. Rough sea condition during the northeast monsoons often results in flooding owing to storm surges, sources added.

The department will also approach Anna University to map the project areas through remote sensing technology. An environment impact study will also be done through a consultant to obtain environmental clearance.

Besides this, measures are afoot to increase the height of the rubble mound seawall from 1.5 metre to 3.5 metre along the shore on Ennore Expressway at a cost of Rs. 26.58 crore.

Repairing the sea wall in the six-km stretch between Tollgate and Ennore is necessary to tackle rough waves. Officials of the WRD said the stretch of shoreline along Ennore Expressway from Kasimedu onwards already had groynes.

Meanwhile, work to construct groynes along the shoreline at Nettukuppam is nearing completion.

This was implemented at a cost of Rs. 1.6 crore, following seawater incursion into neighbouring hamlets a few months ago.

Residents of Nettukuppam said the impact of sea erosion has reduced over the past month, as the groynes have been laid along a length of 240 metre.

Sand accretion has occurred to a height of one metre near the groynes. Residents want the remaining stretch of shoreline to also be secured by repairing the existing sea wall to avoid flooding during the monsoons.

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