The study focused on extreme storm surge scenarios and high tide levels along with flooding in the river and found heavy siltation and narrowness of the mouth of the creek posed flood threat to the adjoining areas.
The flood risk at north Chennai could be significantly minimised by straight training walls at the creek mouth and regular desilting of the river, the study said. An earlier proposal to erect curved training wall would only worsen the situation by blocking the free exchange of seawater with the creek, thereby increasing the flood risk, it added.
Prof V Sundar, Department of Ocean Engineering, IIT-Madras, said, “A straight structure with sufficient crest height is essential to ensure the tidal prism ingress for flushing. Further, in the event the shoreline south of the southern training wall reaches its tip, either dredging or its further extension into a water depth of 6 to 7m is feasible with ease. Further, the straight training walls would act in complement with the present series of groynes which were designed by IIT Madras for shore protection, too.”