KOCHI: From Thanneermukkom to Purappillikavu, hundreds of hamlets located on the banks of Vembanad lake are witnessing mass exodus. Residents, mostly daily wagers, are forced to abandon their homes and shift to rented accommodation due to severe waterlogging.
Normally, the water level in the lake rises during the Malayalam month of Vrischikam (November-December) but recedes within a month. However, there is no respite this time, and the water level remains high as the sea level has gone up due to a phenomenon locally referred to as ‘kallakadal’. Scientists explain this as lateral swell caused by an oceanic current from the South African coast that combines with the current in the Indian Ocean.
“The past four months have been hell for us. Sewage lines have choked and polluted water enters our homes spreading diseases. Our legs start itching once we step into the water and we have to wash our limbs with Dettol multiple times a day. Two people have died of dengue in the Edakochi area in recent times,” said Shiny, a resident of Edakochi.
She said though the previous government sanctioned `4.85 crore to build a bund wall and desilt the lake, the work has been delayed due to tendering issues. “We have decided to take out a march to the village office on Wednesday demanding immediate government intervention,” Shiny said.
She said the residents had met Industries Minister P Rajeeve and Water Resources Minister Roshy Augustine earlier seeking steps to save their lives.
“We have to depend on houses located around 1km away from Edakochi to tend to our primary needs. However, how can young girls and the elderly walk such a long distance and knock on the doors of unknown people? None, including the MLA, mayor or the collector, has visited the area till date,” she lamented.
Chellanam panchayat member K D Prasad said around 1,500 families living in five wards have been affected due to waterlogging.
“Roads have been inundated in many areas and people have to wade through waist-deep water to reach the main road. Families are unable to use toilets in their homes and are forced to depend on houses in high-elevation areas. The panchayat has passed a resolution seeking immediate intervention. It has been sent to the government,” Prasad said.
According to Kerala University of Fisheries and Ocean Studies (Kufos) faculty V N Sanjeevan, who conducted an extensive study on the accumulation of silt in Vembanad lake, water level in the sea has remained high since December, which has caused saline water intrusion in the lake. The tidal amplitude, or difference in high tide and low tide levels, which stood at 1m in coastal areas, has risen to 1.6m, resulting in waterlogging, he said.
“The remote swell caused by the ocean current, rising sea surface temperature and thermal expansion of water in the Arabian Sea due to rising temperature contribute to the rise in seawater level. Water level in Vembanad lake remains high as it is not draining into the sea. I don’t think removing silt from the lake is a solution as it will lead to higher intrusion of sea water. Already, saline water has reached Kottayam district. It is a cause for concern,” said Sanjeevan, who is also chair of the Centre of Excellence for Aquatic Resource Management and Conservation at Kufos.
He said the Cochin Port is dumping sediments dredged from the Cochin Channel, around 10 km off Kochi coast. “If this soil is deposited in low-lying coastal areas adjacent to the seawall, it will help elevate the land. If the government is desilting Vembanad lake, the soil should be deposited in coastal areas to increase land elevation. This is the only solution,” Sanjeevan said.
A study by Kufos found that around 399.5 million cubic metres (MCM) of silt had accumulated in the Vembanad lake, significantly reducing its water storage capacity from 2,677.5 MCM in 1930 to 384.66 MCM in 2020. The lake, which covered an area of 365 sq km in 1900 has shrunk to 206.4 sq km. Its average depth also reduced from 8m to 2.87m.
M D Dhanesh, whose family lived in Edakochi, said they were forced to shift considering the safety of his child as the entire area was inundated.
“Around 350 houses in Edakochi have been hit. Twenty 20 families have already shifted to rented houses. People are unable to sell their land as there is no demand. We have formed a people’s committee to hold a protest and to seek government intervention,” said Dhanesh, the son of CPM branch secretary Dharmajan.
Rising concern
Thousands of houses located on the banks of Vembanad lake affected due to waterlogging
Tidal amplitude (difference in high and low tide levels)
February 1: 1.6m
February 3: 1.55m
Normal tidal amplitude: 1m
Causes of waterlogging
Remote swell waves originating from South African coast
Thermal warming of Arabian Sea
Decline in water storage capacity of Vembanad lake
Shrinking lake
Vembanad lake area in 1900: 365 sq km
Area in 2020: 206.4 sq km
Depth in 1930: 8m
Depth in 2020: 2.87m
Water capacity in 1930: 2,677.5 MCM
Water capacity in 2020: 384.66 MCM
Silt accumulation: 399.5 MCM