Unscientific development and unchecked commercial activities in Kochi are worsening the already acute water crisis
Text: Rochelle D’Souza Illustration: Jithin Mohan Photos: Various Sources
Looming in the shadows of an ever-imminent drought, thanks to the dearth of rainfall in the state, the city of Kochi is facing a different kind of water related crisis. In what seems to be an eye-opener of how development impacts the surrounding environment and the people who live in it, the low-lying areas around Kochi are soon losing their sources of potable fresh water. Since the commencement of its construction in 2005, the International Container Transhipment Terminal (ICTT) at Vallarpadam has witnessed the dredging of millions of cubic meters of silt and sand to help facilitate the coming and going of the vessels to the terminal. The waters of Kochi are subject to a total annual maintenance dredging volume of about 3.5 million m3 (meter cube); about 70% in the main approach channel outside the harbour area and 30% in the interior harbour channels. The increase in depth of the shipping channel, necessitated by the International Container Transhipment Terminal (ICTT), and the further reclamation of land for commercial construction of the Goshree Islands has resulted in salinity rising in water bodies in low-lying areas which add insult to injury when put in a context of the present water crisis.
The Nansen Environmental Research Centre India (NERCI), based in Kochi, conducts basic and applied research projects in ocean and atmospheric sciences and have done extensive work in Kochi with a focus on monitoring the effects of commercial activity on the environment. In a recent study carried out by NERCI, a rather alarming finding was brought to light when researchers found that the areas surrounding Kochi including the locales of Vypeen, Vallarpadam, Mulavukad and West Kochi are quickly running out of sources of potable freshwater owing to alarmingly heightened levels of salinity.
The islands and low-lying areas surround Kochi. Most of these areas are merely 0.75m above sea level and have been facing an increasing shortage of fresh potable water from wells and borewells owing to the high levels of salinity. Every well dug or borewell bored is found to be salty owing to what is known as saltwater intrusion. Intrusion takes place because saline water has a higher mineral content than freshwater, it is denser and has a higher water pressure and as a result, saltwater can push inland beneath the freshwater. Add to this the deficit in rainfall in 2015 and 2016 which has considerably affected the levels of freshwater in the city’s water table, most of the water sources in low-lying areas around the city are turning saline with each passing day. According to the recent study, the presence of elements such as calcium, potassium and magnesium have risen in these low-lying areas, leading to infertile soil, poor quality of ground water and even corrosion of structural foundations.
“After the Vallarapadam terminal started functioning, dredging is being carried out 24X7. With this, the depth of the shipping channel has increased from the earlier 10-12 metres to 18 metres. Although the depth of the channel is merely 18m, the depth just beyond the mouth of the harbour is 1,000m. When the depth of the channel increases, however minor that increase is, there would be a sudden and powerful rush of water from the sea inland, which in turn floods low-lying areas. During high tide, the water level increases furthermore.” said Dr N R Menon, the leading scientist, chairman of the Scientific Research advisory board and one of the Board Directors of NERCI. Dr Menon has conducted extensive research in the realms of Marine Biodeterioration; Marine Pollution Monitoring; Toxicology Biodiversity and coastal zone management.
“Vegetables such as chillies, bitter gourd and drumsticks were once grown by residents. But now the plants just wilt and die. It has also been found that many wells, which once provided fresh water, and even borewells have turned salty. The salinity in the soil has also weakened the structure of houses, as the salts in water have an impact on the durability of building materials. This causes cracks and dampness to walls and foundations. The salt also leads to the corrosion of metals and adds to the weakening of structures,” he added. The areas around Kochi particularly Vallarpadam, Mulavukad, Wellington Island and Vypeen are home to major commercial projects like the LNG and container terminals, the wharfs, and so on, with a great deal of infrastructure bring planned in said areas, the durability and lifespan of which will be compromised by the salinity.
The flooding of low-lying areas has also been attributed to the increasing reclamation of the backwaters for commercial construction. “Reclamations on large tracts of land adds to the problem. Let us take the example of the construction by a multinational company at Bolgatty. There was once 5m of water in 30 acres of land which has now been reclaimed. This water doesn’t just disappear or evaporate. It is displaced to low-lying areas,“ Menon said.
According to Cochin Port Trust (CPT) authorities, the dredging needs to be carried out constantly due to the high rates of siltation. But alternative studies and projects are being conducted to find a better solution. “At 21 million cubic metres per year, the Cochin Port has the highest siltation among Indian ports. This necessitates year round dredging. Now, we are looking at alternatives like nautical depth dredging and water injection mode of dredging as well as the construction of two breakwaters at the mouth of the port where the `outer harbour project’ is to come up,“ said port officials. All around us are classic cases, like this one, of how development can impact the surrounding environment and at the rate at which it seems to be going, the future seems to be uncertain. Sustainable development and scientifically backed up commercial operations is the need of the hour and with an imminent drought at the doorsteps of our state it must be brought to light that what’s happening in Kochi is not an isolated incident.
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