‘Maintenance dredging may harm Kochi port’
Unsustainable maintenance dredging may seriously damage the Kochi port, a former officer with the Indian Navy has said.
Maintenance dredging involves removal of accumulated sediment.
In his book, ‘The Untold Story of a Coast,’ which was released last week, Commander (Retd.) John Jacob Puthur writes that Robert Bristow built the modern Kochi port in the 1920s in such a manner that will not have required maintenance dredging.
“This was until the mid 1980s, when the Navy built its South Jetty in contravention of the guidelines proposed by Bristow. It cut off the sediment supply to the once beautiful Fort Kochi Beach, and so it eroded away. There is no beach left now, but an ugly seawall. At the same time, the sediments that should have replenished the beach went on to accumulate at Vypeen Coast, to create a new landscape, the Puthuvypeen. Then the Vallarpadam Container Terminal came to be built, east of Vypeen,” he writes.
He states that dredging along the terminal will cut off the sediment supply further seaward, that is, to Puthuvypeen. “So instead of accreting further, Puthuvypeen will now erode. The process must have begun already. This could be environmentally dangerous because several tanks to store petroleum products have been built there. The tanks are also exposed to the strong salt-laden monsoon winds, which in turn could cause excessive corrosion. What if one of the tanks, due to excessive corrosion, cracks open and spews its deadly contents into the Kochi Port? Even Vallarpadam terminal lacks shelter from the strong monsoon winds. Therefore, handling containers may be a very difficult proposition during monsoon, which lasts up to four months, from May to September. As a combined outcome of the developments that began with the South Jetty, siltation has increased manyfold. Now the port has to carry out maintenance dredging right through the monsoon in order to function,” he writes.
In his foreword to the book, Admiral (Retd.) Arun Prakash, former Chief of Naval Staff, says that Puthur’s attempt to question conventional wisdom may evoke scepticism and indignation in some quarters or fuel a controversy. “But then, which iconoclastic seeker of truth did not elicit righteous anger and resentment from those who wished to cling to the known and the familiar,” he asks. Commander Puthur, who claims to have devoted the best part of his life to study the Indian coast, hails from Thrissur and is settled in Bangalore after his retirement.
An alumnus of the National Defence Academy, he was Chief Instructor of the National Institute of Hydrography, Goa, and had led, in 1998, a hydrographic surveying team to Antarctica.
The book discusses the Sethusamudram Shipping Canal project, Kalpasar Project, which envisages constructing a dam across the Gulf of Khambat, and many other coastal issues.
He told The Hindu that coastal erosion, generally attributed to phenomena such as monsoon, was mostly created by man.
“A coast will erode only when its sediment supply, invariably from land, is disrupted. It need not arise from action of waves. Waves and coasts have coexisted. Disruption of sediment supply to the coast happens mainly as a result of ill-conceived projects on the coast’s ports, coastal roads, dams and barrages on rivers,” he says.
He states that the first serious case of coastal erosion in Kerala happened at Chellanam in the 1960s. “It began in the very first monsoon that followed the construction of the Kochi-Chellanam Road. Only seawalls are built now to combat erosion. They do not offer long-term protection to an eroding coast. Coastal erosion will not stop until sediment supply is restored to the coast. But then, there are no easy solutions,” he observes.
The Kochi Port came into existence after the 1341 AD flood in Vembanad breached the coast at Kochi.
“This in turn wiped out the ancient port of Muziris, which operated since prehistoric times, at the mouth of Periyar. What if there is another flood in Vembanad, say, after a downpour, as it rained over Mumbai in 2005? The much- depleted Chellanam Coast could then breach. With this, the Kochi Port could cease to exist almost overnight. Are we prepared?” he asks.
Source: The Hindu