Chennai began its urban growth trajectory at the mouth of the Cooum River. Today, the city rapidly expands beyond Adyar River into marshes, farmlands, and forests - indiscriminately turning a largely wet and permeable landscape into concrete. As rivers, canals, and other hydrological networks are disrupted, Chennai has become a low-lying city that is unprepared to face the regular stresses of the monsoons and unprecedented shocks from extreme rainfall or cloudbursts. The city faces multiple water-related risks — from flooding to sea level rise to aquifer depletion. Yet, the urban typologies and planning paradigms of the city are indifferent to the region’s ecological realities and challenges.

PROTECT, DELAY, STORE, RELEASE is a four-step water management approach that aligns regional planning priorities and neighbourhood plans with the hydrological cycle of Chennai’s basins. The Buckingham canal traverses multiple basins including the Adyar River basin and the Buckingham canal Chennai sub-basin. The canal’s ability to withstand cloudbursts is inevitably linked to the preservation of upstream blue-green systems and a network of infrastructures within the city that can slow down runoff, store rainwater, and release into the aquifer. As such, we propose a SPONGE BASIN framework that is regional in scope but requires landscape-based interventions at various scales. The project uses the Buckingham canal area to demonstrate how the Sponge Basin framework can lead to the re-imagination of urban neighbourhoods, transit stations, open spaces, streets, and the rejuvenation of multi-functional infrastructures like the canal itself.

Our analysis reveals existing parks, green cover, low elevations along the canal stretch that can be made to work together as a SPONGE BASIN. Two sites are identified to test the opportunities in more detail. Site 1: SPONGE Neighbourhood demonstrates the potential of new development typologies with a public realm that is well adapted to delay, store, release during cloudbursts. Site 2: SPONGE INFRASTRUCTURE depicts how the Sponge Basin framework can be realized within the constraints of existing infrastructure through the insertion of best storm water management practices along strategic streets and opening up the edge of a restored canal.