Jakkur Lake Constructed-Wetland Rejuvenation — Bengaluru's Sewage-to-Ecosystem-Service Water Fund

Like many of Bengaluru's roughly 200 urban lakes, Jakkur Lake had become a dumping ground for untreated sewage by the 2000s. In 2008 the Bangalore Development Authority, with support from the Karnataka Power Corporation Limited for the treatment plant, built an integrated wastewater-to-wetland system to intercept sewage before it reaches the lake.

A UASB treatment plant handles about 10 million litres of sewage a day, feeding a roughly 4.6-hectare constructed wetland of macrophyte beds (Typha, Cyperus, water hyacinth and others) and an algal polishing basin before the water reaches the lake. Since around 2014, day-to-day maintenance has been run by the community-based Jala Poshan trust — six women from self-help groups plus fishers — funded by donor contributions and BBMP allocations rather than direct fees, since BBMP rules bar official income-generating activity at the lake.

Published water-quality monitoring found the wetland's first treatment stage removes roughly 45% of Chemical Oxygen Demand, 66% of Biochemical Oxygen Demand, 33% of nitrate-nitrogen and 40% of phosphate, and testing of around 300 nearby borewells found rising water levels and lower nitrate concentrations within half a kilometre of the lake. The restored lake now supports approximately 197 recorded bird species, including nesting spot-billed pelicans, and sustains about 70 fishing families and 30 cattle-owning or grass-cutting families, with fishers reporting catches of up to 500kg on good days.

The model is now cited as a template for other Bengaluru lakes, but its funding is patchwork and maintenance-dependent (roughly 1.5–2 lakh INR/month raised informally) rather than backed by a guaranteed public payment stream, and researchers caution that without secure long-term financing, wetland performance and community stewardship arrangements like Jakkur's can be difficult to sustain or replicate at scale.