Open Code, Curated Data: Building Open Water Intelligence for Indian Cities

Neer Vazhvu (neervazhvu.org) is an open-source platform that turns scattered public water data into living, interactive maps. It is live across three Indian cities (Chennai, Madurai and Bengaluru), with a fourth, Mumbai, in progress, built by a very small team.

The starting problem: a city's water data sits in many separate silos, across different departments, portals, and formats, so no one sees the whole picture and the warning signs get missed.

The heart of the talk is architecture: how we serve several cities from one codebase. A new city is mostly configuration, data, and capability flags rather than a forked codebase, and I will be honest about where that discipline holds and where it leaks.

How the system is designed for partners to contribute data without us as the bottleneck: fixed layer contracts plus ingest and validation scripts, so onboarding a new river basin is meant to be a manifest and a data drop rather than a rewrite.

The data pipelines: parsing government PDFs, portals, and satellite imagery into standardized, provenance-tagged layers.

The honest part: the code is the easy bit. Curated, maintained, trustworthy data is the hard one. I will cover what "open" really means here, why open source and open data are different problems, and the open question of how a civic project stays both open and sustainable.

A live demo across the cities.

1. A reusable pattern for building multi-city civic platforms from one codebase, using configuration and capability flags instead of forking.
2. A clear-eyed distinction between open source and open data, and what each means for a public-interest project.
3. A realistic picture of what it takes to sustain open civic infrastructure with a very small team and almost no budget.