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De-silting work being done in Chennai
De-silting work being done in Chennai|Photo credit: Annie Catherena
Environment

De-silting Continues As Monsoon Begins, Poses Health Hazards

Corporation of Chennai under fire for improper de-silting methods and for delay in removing silt

Annie Catherena

Annie Catherena

P Kumar is a resident of Kaiveli, near Madipakkam in Chennai. He is upset because improper de-silting near his home has led to breeding of mosquitoes and other problems for his family and other residents.

“The (Greater Chennai) Corporation has decided to de-silt the canal, well and good,” says Kumar. “But they should clear the silt and other garbage at least within a few days before it gets washed back into the water again.”

Kaiveli is one of the many residential areas along the Veerangal Canal.

Originating from the Adambakkam tank, the canal runs along Adambakkam and Puzhuthivakkam before emptying into the Pallikarnai marsh. Originally built to channel rainwater into the marsh and to prevent flooding of residential areas near the marshland, the canal now is blocked by a grill on one side to prevent any garbage flowing into the marsh.

“Although fogging and other measures like distribution of medicines is done as precautionary steps, mosquitoes are an inevitable menace, mainly because of the incomplete de-silting of the water bodies,” says Kumar, who has been living in Kaiveli for more than seven years.

Although Corporation officials have removed the hyacinth (an invasive weed growing on the surface of water bodies, preventing flow of water) from the canal near the Velachery MRTS (Mass Rapid Transport System) and rectified the water flow, the silt was removed from the road after more than a week, says P Muthu who is a painter by profession and resides in Kaiveli area.

“The silt was left here on the main road and in no time, it became a small dumping yard,” said Muthu.

“On top of it people use this canal to throw garbage. Even if someone in Adambakkam threw one plastic cover, before it reaches the marsh, it gets blocked here and the water stagnates. And when water stagnates, there a higher chance of mosquitoes breeding in it,” he continued.

Veerangal canal in Velachery
Veerangal canal in Velachery
Photo credit: Annie Catherena

How The Chennai Corporation De-Silts

With the arrival of the north east monsoon, de-silting of major and minor canals in the city is still under process. Although de-silting work is done all through the year, clearing of water ways and storm water drain before the monsoon plays a vital role.

According to the Greater Chennai Corporation, zone-wise de-silting is usually done twice a year by departmental de-silting squads or through contract workers. The removed silt is technically supposed to be carried to the respective dumping yards immediately - Kodungaiyur dumping yard for north and central Chennai and Perungudi for areas under south Chennai.

“Sometimes, the removed silt is not only wet but also mixed with sewage water. This has to be left in the open to be dried, or it will pollute the roads all along. Usually, we take it out within a day, and if it takes longer than that, it may have been because of rain or some technical problem,” a Corporation official explained under condition of anonymity.

During the NE monsoon preparedness meet in October this year, Corporation Commissioner G Prakash had mentioned that more than 252 contractors were assigned to de-silt approximately 5000 water bodies. 30 major canals and 18 canals under the Public Works Department had been de-silted and rejuvenated.

Almost three lakh metric tons of silt had been removed from canals and lakes and 2.5 lakh metric tons from water channels and manholes. Water stagnation due to blockage in streamlines (small water channels) were also removed.

Silt in water bodies is removed and collected in a bag. According to guidelines given to contractors, they are asked to puncture this bag to let excessive water out. “Only sometimes when the silt is mixed with mud and sewage waste, the workers don’t use the bag. Otherwise it is mandatory to use the bag,” said the Corporation official.

For accountability, the longitude and latitude of the place where the desilting work is done is noted and photographs are taken. The amount of silt and garbage removed is then weighed and dumped in the respective dumping yards. The contractors are then paid accordingly.

Although 80% of work is completed, the remaining 20% of the work is still underway, said the official.

Silt and mud left on the road after de-silting water bodies
Silt and mud left on the road after de-silting water bodies
Photo credit: Annie Catherena

De-Silting During Monsoon: A Futile Exercise

“The silt usually gets carried back into the water or storm water drains when it’s left on the roads or on the banks to dry. The storm water drains and canals not only carry rain water with silt but is also mixed with sewage. When it is kept in the open to dry for a long time it also poses a health hazard,” says Jayaram Venkatesan co-founder of Arappor Iyakkam, an anti-corruption organisation.

On asking the Corporation official regarding delay in disposal of silt, he said, “There might be two or three cases in which we might have delayed, probably because the silt wasn’t dried, otherwise we take it to the dumping yard on the same day. We also have a WhatsApp group to address complaints from different zones. Apart from that, complaints through our helpline and website are always addressed in 2 days,” an official from the storm water drain department said.

According to Jayaraman, the whole process of de-silting by the corporation has been done the wrong way.

“The de-silting work should have been completed by August or September. They should have anticipated monsoon in October and finished the de-silting work. This way there is no risk of silt and garbage getting washed back into the water bodies. De-silting during rains itself is a bad idea as there are chances of water borne diseases and other health issues,” he said.

“The Corporation should ensure all de-silting and removal of blockages from water bodies and streamlines is completed before the monsoon hits,” he concluded.