Check dam-cum-bridge at Somangalam to help harness flood water, contribute to Chennai’s water.

A check dam-cum-bridge being built across a tributary of the Adyar river at Somangalam near Tambaram, is expected to harness flood water and mitigate floods in the neighbouring localities, during the northeast monsoon. This could also turn into another water source to meet the growing drinking water needs of the city, officials said.

About 80% of the ₹4.5 crore project, which is being executed by the Water Resources Department (WRD), has been completed so far. Officials said many surrounding areas were inundated during the 2015 floods as the causeway then did not have the capacity to discharge surplus water.

The check dam under construction, has been designed to discharge a maximum of 3,200 cubic feet per second (cusecs) in the location. The storage structure is being built for a height of nearly 2.1 metres across the 36-metre wide tributary. The structure would have a capacity to store 34 million cubic feet. This would not only help groundwater recharge for domestic needs in the surrounding areas, but also raise the water table for irrigation needs.

Surplus water from water bodies in southern suburbs such as Naduveerapattu Periya Eri, Chitteri and Manimangalam is discharged into the Somangalam tributary. It travels for nearly 6.5 km and joins the Adyar river, and the check dam is being constructed at the third km point of the tributary, officials added.

A bridge would also come up over the structure to connect Somangalam with other areas such as Naduveerapattu and Manimangalam. The project is set to be completed in about a month.