Kallai, which flows through the heart of Kozhikode city, was deemed as the most polluted river in Kerala in a recent report of the Central Pollution Control Board (CPCB). The river pushed Karamanayar in Thiruvananthapuram, which was the most polluted river as per the 2022 report, to the second position in 2023.
The biological oxygen demand (BOD) that determines the level of oxygen in water, for Kallai is 12.8 milligrams, while the admissible amount is 3 milligram. The faecal coliform count (FC Count) that determines the amount of faecal matter in the water is 4,10,000 to 4,40,000 per 100 millilitres in Kallai, while the admissible amount is 2,500 per 100 millilitres, as per the statistics provided by the National Water Quality Monitoring Programmes (NWMP). The BOD was within the admissible limit in Kallai during the last report. It has risen to this level within a year. However, the FC Count that was 7,90,000 has come down this time. The condition of Kallai could be attributed to the discharge of pollutants from industries and drainage systems across the city that were being channelled into the river through the Conolly canal.
The district administration had identified drains that opened into the Conolly canal and Kallai as part of an investigation held after the floods in 2018 . However, no action has been taken against the polluters aside from issuing a few notices. The dumping of solid waste on the banks has exacerbated the issue. The water appears black in colour, and silt accumulation on the riverbed has impeded its flow, causing the water to stagnate.
Large-scale encroachment was cited as another issue. The Revenue department has identified 35 acres of encroached land along its banks. The Kerala High Court order of 2021 to clear the encroachments has not been implemented so far.
Attempts to de-silt the river and restore water flow by both the State government and the Kozhikode Corporation have been unsuccessful. The State government had allocated ₹4.5 crore to de-silt the river around 20 years ago,with no action taken. Similarly, Kozhikode Corporation set aside ₹7.5 crore nearly 10 years ago for the same purpose, yet no progress has been made. The Department of Irrigation floated several tenders for the work, but there were few takers. Given the higher cost involved, the Corporation recently sanctioned an additional ₹5.9 crore, thus making the total allocation of fund above ₹13 crore.
