Bengaluru’s Arkavathi stretches feature in pollution assessment

Bengaluru’s rajakaluves are carrying sewage into lakes, while most of the city’s identified polluted river stretches lie along the Arkavathi, a Karnataka State Pollution Control Board official said.

The board’s August 2026 assessment covered 66 monitoring locations across 14 polluted stretches in Karnataka. It recorded high biochemical oxygen demand and faecal-coliform counts at several locations. High oxygen demand leaves less dissolved oxygen for aquatic life, while faecal contamination can indicate the presence of disease-causing pathogens.

Hydrogeologist KC Subhash Chandra said natural drains have become conduits for sewage from residential areas. Water conservation expert Vishwanath S said domestic sewage is larger in volume, while industrial effluents can have a greater impact.

The pollution board said action plans exist for all identified stretches, but gaps in underground drainage, funding constraints and coordination among urban local bodies and panchayats have slowed work. It said it expects phased sewage-treatment and drainage works, prioritising Bengaluru along with Mysuru and Mangaluru, to be completed over the next two years.