Explained| Chellanam’s new tetrapod-based seawall

M.P. Praveen

Explained| Chellanam’s new tetrapod-based seawall
Why was this new installation necessary? How has it improved the lives of the coastal residents? The story so far: Over the past few years, Chellanam, an idyllic coastal village in Kerala’s Ernakulam district, would unfailingly hit the he...
Why was this new installation necessary? How has it improved the lives of the coastal residents?

The story so far: Over the past few years, Chellanam, an idyllic coastal village in Kerala’s Ernakulam district, would unfailingly hit the headlines during the monsoons for massive sea incursion and widespread destruction of homes. However, this monsoon, despite heavy spells of rain lashing Ernakulam district from May, Chellanam has remained largely unaffected thanks to the construction of a new tetrapod-based seawall. 

What used to happen before?

Earlier, the conventional seawall of Chellanam failed to check sea ingress which resulted in massive ruin and destruction. This triggered one of the longest-running protest campaigns, which is now well past 1,000 days, demanding a permanent solution. Coastal erosion, which intensified after Cyclone Ockhi in 2017 further worsened with Cyclone Tauktae last year, leaving many residents in relief camps for extended periods. Since then, many of them chose to either seek rented accommodation for shorter durations or relocate forever by selling off their small holdings under the State Fisheries Department’s Punargeham project in the face of periodic onslaught by the sea which rendered their homes uninhabitable.

Now, due to the tetrapod-based seawall, residents of the coastal village vouch that even those stretches that were most vulnerable to sea erosion have remained by and large safe. Many said after years of living on tenterhooks, expecting to move to relief camps with their belongings at the most unseemly hours, they could sleep in peace during this monsoon.

What are the contours of the seawall project?

The construction of the tetrapod-based seawall forms the foundation of the ₹344 crore coastal conservation project being implemented by the State government in Chellanam. The six networks of groynes being erected along the Chellanam Bazar area, which used to face the wrath of the sea in the past, are also part of the project.

In the first phase, the wall is being constructed in a little over seven-km stretch between Chellanam harbour and Puthanthodu. The Kozhikode-based Uralungal Labour Contract Co-operative Society (ULCCS), one of India’s oldest worker cooperatives, which is entrusted with the production and deployment of tetrapods, assures that the work is well on course to finish before the next monsoon. The project was launched on the basis of a study conducted by the Chennai-based National Centre for Coastal Research (NCCR) while the work is being supervised by the Anti-Sea Erosion Project Management unit of the Irrigation department. Tetrapods are being set upon a 2.5-metre foundation of granite and at a height of 6.1-metre from sea level as per the norms set by the NCCR. A three-metre-wide walkway is being readied over the tetrapod seawall along a stretch of 6.6-km in the first phase.

How much has the project progressed?

Although the project was formally inaugurated by Chief Minister Pinarayi Vijayan in July, work had commenced a few months before that. On an average, the ULCCS deploys about 350 tetrapods of different tonnage depending on the depth of the sea along the coast. But when the sea turns rough, the work slackens thanks to the difficulty in engaging divers to help position the tetrapods on the coastal bed.

The UILCCS has also set up casting yards at select locations along the shore to churn out tetrapods. Typically, up to 600 tetrapods can be produced in a day when work progresses without hiccups. The agency has been able to produce 20,235 tetrapods using 3.5 lakh metric tonne boulders so far.

What lies ahead?

Demand is already rife for the launch of the project’s second phase to extend the seawall along the remaining 10-km stretch of the coastal part between Kannamali and Kaithaveli. It is understood that the estimate for the next phase is being drawn up right now. In addition, a detailed project report (DPR) for a ₹941-crore scheme to develop Chellanam into a model, eco-friendly fishing village has also been submitted to the State government by the Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala State Coastal Area Development Corporation (KSCADC).

How has the project been perceived?

There are still voices of dissent. The Chellanam Janakeeya Vedi, which has been at the forefront of the protest demanding a permanent solution to sea erosion, dismisses the tetrapod-seawall as a temporary solution at best. The group is peeved about the ‘publicity’ garnered by the success of the project, which it sees as a “political ploy by the government to hide its failures”. Beach nourishment reducing the depth of the sea along the shore alone offers a permanent solution, it contends. Meanwhile, environmentalists have warned that large scale extraction of stones to manufacture tetrapods could aggravate the natural disasters that the State has been witnessing lately.

THE GIST
The conventional seawall of Chellanam failed to check sea ingress which resulted in massive ruin and destruction. Now, due to the tetrapod-based seawall, residents vouch that even those stretches that were most vulnerable to sea erosion have remained by and large safe.
The construction of the tetrapod-based seawall forms the foundation of the ₹344 crore coastal conservation project being implemented by the State government in Chellanam. 
However, some are of the opinion that only beach nourishment (reducing the depth of the sea along the shore) offers a permanent solution.

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