Residents of Thanthonnithuruthu have been demanding measures to prevent severe shoreline erosion caused by wave and tidal actions, as well as saline water intrusion.
| Photo Credit: THULASI KAKKAT
The proposal to construct an outer bund for Thanthonnithuruthu Island, located in the Kochi backwaters between Ernakulam and Mulavukadu, was cleared by the Kerala Coastal Zone Management Authority (KCZMA) on Friday (February 28, 2025).
The project, proposed by the Goshree Island Development Authority (GIDA) in 2021, was revised after the KCZMA raised concerns about potential flooding and mangrove destruction. The width of the bund wall was reduced from five metres to three metres. The GIDA also assured the KCZMA that the project would not affect mangrove vegetation in private holdings on the island.
The islanders had been demanding measures to prevent severe shoreline erosion caused by wave and tidal actions, as well as saline water intrusion. The GIDA proposed the outer bund construction as an effective solution to curb coastal erosion and frequent flooding.
The proposal involved constructing an outer bund filled with dredged soil, reinforced with concrete piles and slabs. The GIDA plans to complete the project in two phases. The first phase includes building a 600-metre retaining wall, with 310 metres on the eastern side and 290 metres on the western side.
The retaining wall will incorporate concrete piles and slabs as part of the bund structure. The bund will be filled with dredged soil, held in place by concrete piles and slabs on the water-facing side, while the inland side will be protected with random rubble masonry, according to project documents.
The top level of the proposed bund will be at least 1.793 metres above mean sea level, significantly higher than the maximum recorded tide level of +1.212 metres at the nearby Willingdon Island station. This elevation will effectively prevent tidal flooding, according to the documents.
The GIDA had agreed to install sluice gates at the bund to drain rainwater that might accumulate inside the concrete structure. The sluice gates were to be installed during the second phase of the project, the GIDA authorities informed the KCZMA.
Responding to the developments, Minister for Law and Industries P. Rajeeve said the construction of the bund would end the plight of families residing on the island. The government would ensure the timely completion of the project, he said in a communication.
Published – March 01, 2025 01:06 am IST
