With no dredging for six months, the Ennore estuary is clogging up with sand deposit. In a bid to understand the sand bar formation at its mouth and tackle it, the Water Resources Department (WRD) has asked the National Institute of Ocean Technology to do a technical study.
As sand bars blocked a large extent of the river mouth, they hinder tidal wave action and free flow of water. This has also affected the livelihood of fishermen in neighbouring hamlets who complained about limited access to the sea.
Though the estuary falls under the control of WRD, it was not involved in deepening or dredging work as the Ennore Thermal Power Station was removing sand bars.
The Ennore Thermal Power Station had suspended dredging work six months ago due to administrative reasons prompting the WRD to act. While the original width of the Ennore estuary is nearly 1,100 m, sources in the WRD sad that it must be free of siltation for up to 750 m for better tidal wave action.
Three-month study
Officials of the WRD said that technical advice of the NIOT has been sought to study wave action, volume of sand deposit and extent of deepening essential to minimise siltation.
The three-month study would also offer suggestions on the feasible technology to be used, including groynes or tetrapods found in Kasimedu harbour or geo-synthetic tubes to tackle sea erosion.
The Kamarajar Port Limited is funding the ₹1.2 crore study. Once completed, the recommendations would be implemented within a few months. Moreover, the study is also required to suggest the extent of removal of sedimentation between Ennore and Pazhaverkadu, an official said.
Fishermen in the neighbouring 18 hamlets too stressed on the need to deepen the estuary. Unless the estuary is cleared of sedimentation, floodwater from Kosasthalaiyar river and Buckingham canal would spill over the banks and inundate their areas, they said.
V. Desingh, a resident of Nettukuppam, said the estuary width had shrunk to just a few hundred metres and only minimal width was available for entry into the sea for fishing boats. The impact of tidal action would be more and prove risky to boats. During low tide, boats got stuck in the sand. The mouth must be deepened by at least 2 m for free flow of water, he said.
