As sand deposits clog the Ennore estuary for want of desilting, sedimentation at Ennore estuary has been a major environmental concern. The National Institute of Ocean Technology has initiated a survey to find remedial measures that would ensure smooth fresh water exchange with sea.
After the Ennore Thermal Power Station suspended dredging work nearly a year ago for administrative reasons, the Water Resources Department (WRD), which manages the estuary, has sought the NIOT’s assistance for a technical study on ways to minimise siltation and have the mouth open for free flow of water throughout the year.
With the study expected to take four months to complete, the WRD would begin deepening and desilting the confluence point of sea and estuary for a distance of nearly 1.5 km from Monday ahead of the Northeast monsoon.
This would be done till January next year. Moreover, the stretch of North Buckingham canal between Ennore creek and Araniar confluence point for a distance of nearly 10.5 km would be widened and desilted at a cost of ₹2 crore, said WRD officials.
Flooding threat
Prolonged clogging of the estuary due to sand deposits would make the surrounding areas vulnerable to flooding during the monsoon. This would also affect the livelihood of fishermen, who have only limited access to the sea because of siltation. The Ennore estuary must be free of siltation for a length of a minimum of 200 m.
In a bid to provide a permanent solution to the issue, the team from NIOT has started a bathymetric survey that would measure the depth of the sea and estuary and water level in estuary.
M.V. Ramanamurthy, project director, NIOT, said the estuary gets sand deposits between April and September as winds bring waves from south. One of the solutions is construction of a training wall, which would direct the flow of waterway and help tidal action.
“We plan to design a training wall near the creek in such a way that there would not be any sea erosion in the shoreline upstream and ensure free flow of water. This would also reduce salinity and improve the livelihood of fishermen who depend on the Ennore creek,” he said.
The work would be taken up early next year after obtaining Coastal Regulation Zone clearance.
