In its affidavit to the National Green Tribunal (NGT), the Kolkata Port Trust (Syama Prasad Mookherjee Port) has contradicted green activist Subhas Datta’s views on the possible causes of Indian Botanic Garden riverbank erosion.
Captain Abhijit Ghosh, director of the port naval department, said in the affidavit there was no scientific link between dredging and riverbank erosion. The port has only been observed to have dredged the fairway for the movement of ships to and from Kidderpore harbour.
The affidavit confirmed that the water carrying capacity of 4.7 square kilometers between the expanse from Shalimar to Kidderpore in the north and Metiabruz in the south has remained the same for the past 20 years.
According to the affidavit, the port records confirmed that no dredging was taking place near the eroding shore.
It states that dredging will be carried out in the shallow area of the canal and the dredged silt will be carried to the nearest deep pocket where it will be dumped. The depth of the channel and deep pockets are regularly monitored by the port.
The affidavit claimed that erosion along the western shore was caused by the propagation of strong tidal waves. During the equinox, when the moon exerts a strong gravitational pull on the earth, it causes extensive damage to the shore. Discharging the entire river was not economically viable. It was said that only navigable canals would be dredged.