Two canals that join the Kallayi river are Canoli canal in the north and Beypore Kallayi canal in the south. Canoli canal or Elathur-Kallayi canal, which has a length of 11.5 km, connects Kallayi river and Elathur.
CWRDM scientist Dr. Harikumar says a major contributor to pollution downstream of the Kallayi river is Canoli canal. The accumulated solid waste and black silt mixed with sand obstruct the free flow of water. Also, the size of waste islands have been increasing periodically.
The Canoli canal, which was constructed during the British rule for inland water transport, is facing issues such as weed infestation, discharge of untreated effluent from the City and suburban areas, dumping of hospital waste, siltation and unprotected embankment, Besides, discharge of effluents from nearby workshops and garages and untreated waste from septic tanks add to the problem.
Dr. Harikumar says even though some schemes for the protection of Canoli canal and Kottuli wetland are being carried out, the Beypore-Kallayi canal has by and large been neglected.
