Faults in Bengaluru’s stormwater drain infrastructure, rapid concretisation, loss of lakes and the mixing of sewage with drainage networks emerged as major contributors to urban flooding during the Bengaluru Stormwater Drains Datajam organised on Saturday, May 23 at the BLR Design Centre on Church Street. The event brought together citizens, researchers and data experts to analyse audit data from drains across the city and identify patterns behind recurring flood-related problems.
Organised by OpenCity, an initiative of Oorvani Foundation, and in collaboration with MOD Foundation, WELL Labs, Biome Trust and Sponge Collaborative, the day-long event was held under the ‘Building a Resilient Bengaluru’ initiative supported by the Bengaluru Sustainability Forum Small Grants Programme.
The datajam began at 10am with an introduction to the datasets and objectives of the exercise. Participants from diverse professional backgrounds — including urban planners, hydrologists, architects, environmentalists, researchers and data scientists — were divided into six teams. Over four hours, the teams selected specific problem statements and carried out analyses using datasets collected through Guided Citizen Audits of Bengaluru’s stormwater drains (SWDs).
The audit data offered an on-ground assessment of the city’s drainage systems and was combined with other datasets such as official SWD maps, lake networks, topography and land-use patterns. Participants examined how the functioning of drains, changes in land use and surrounding infrastructure contribute to localised flooding and water contamination.
“What’s exciting about this Datajam is seeing that data contribute to larger conversations around public health, contamination, and condition of the infrastructure and the spending going into it,” said Amritha Ganapathy, Research Associate at MOD Foundation.
Each team presented its findings in 10-minute sessions. Team ‘Kaluve Kollective’ found that green buffers around drains helped reduce heat, while heavily concretised areas became heat hotspots. Team ‘Curious Public’ studied drains in the Shivajinagar constituency and analysed how dense built-up areas and reduced permeability affected water quality and flooding risks.
Additionally, Team ‘Vrishabhavathi’ traced land-use changes over several decades, identifying areas where lakes had disappeared and natural drainage channels had been altered, linking these transformations to present-day flooding patterns. Team ‘Watershed Guardians’ examined whether industrial clusters were contributing to stormwater pollution and whether residential areas were also discharging waste into SWDs.
Team ‘Parisara Dala’ explored the relationship between informal settlements and stormwater drains, focusing on flooding, sewage inflow and the availability of nearby healthcare facilities. Team ‘Toxic Karma’ mapped intersections between sewage lines, water supply pipelines and stormwater drains to study how contamination of drinking water could affect public health.
Since 2023, Oorvani Foundation has organised six to eight datajams annually across Bengaluru, Chennai, Mumbai and Hyderabad. The Bengaluru stormwater drains event marked the Foundation’s 20th datajam. Previous editions have focused on themes such as urban heat, biodiversity, public transport and constituency-level civic issues, especially around elections.
According to the Programme Lead at Oorvani Foundation Vaidya R, the initiative was started to encourage community participation and involve professionals comfortable working with data in solving civic challenges.
“We have worked with governments like the BBMP and the Maharashtra State Climate Action Cell, and the outputs have been directly presented to them,” Vaidya said, adding that such collaborations demonstrate public interest in urban problem-solving.
This article was written by a student interning with TNM.