Urban Lakes

Urban lakes perform multiple functions –groundwater recharge, flood control, and environmental amenities. To understand how lakes are integrated with the larger water system in Bangalore, we have initiated detailed hydrological and water quality analyses in two lakes – Jakkur and Rachenahalli - in Bangalore, in collaboration with Biome Environmental Solutions and community groups like Jalaposhan. Only half of Jakkur Lake catchment is urban, almost 80% of Rachenahalli lake’s catchment is now urban. We have begun installing sensors in the lakes and at the inlets and outlets. Because the catchments of Jakkur and Rachenahalli lie along a continuum of urbanization, we hope to understand how the lake water balance and the contributions of treated sewage, untreated sewage and storm water changes within a year and over time.

We hope to model water quality and quantity to understand how urbanization affects the different functions of the lake. This will allow us to project the future state of the lakes over the next 30 years and suggest how they may best be managed to address Bangalore’s water needs.

Equity and Efficiency:

While BWSSB has also put in place a progressive tariff structure to ensure that the poorest are less impacted, and has made efforts through its social development unit, recent assessments show that the situation on the ground leaves a lot to be desired. Several pockets in the city are under-served by public water supply and estimated LPCD levels vary hugely, raising questions of inequities in distribution of water.

At present, we have begun assessing equity issues around Bangalore’s water at two levels:
At a macro-scale, we are working to analyze 2011 Housing Census Data from the Govt. of India. Initial analysis and mapping of types of water and sanitation sources used by households in Bangalore has been done using this dataset. The maps clearly show that while central Bangalore receives most of the imported piped water supply, the fast growing peri-urban suburbs get very little and are consequently groundwater dependent.
At the micro-scale, we are engaged in field-work in slums in Bangalore to understand concerns over inequity.

Wastewater recycling:

Wastewater recycling has been promoted as a possible solution to Bangalore’s extreme water scarcity problem. We address the research gaps in understanding the potential for wastewater recycling in Bangalore. The idea would be to come up with a more realistic 'supply' curve of recycled water. At the moment, most sewage in Bangalore is untreated. Moreover, there are different scales at which wastewater is currently being treated. Each of these scales of treatment entails different models of how wastewater recycling and use (WWRU) should be approached because the scale, ownership and regulatory structures are different. We have begun work on apartment-level micro sewage treatment plants using primary data shared by CDD and our own surveys of apartment level STPs.