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Asian Development Bank

100 Climate Actions from Cities in Asia and the Pacific


A huge infrastructure investment program, covering 10 cities in the state of Tamil Nadu and costing $1.2 billion, aims to implement climate resilient water supply, sewerage, and drainage systems across the region.

India’s southern state of Tamil Nadu wants to promote climate resilient urban development, as the lack of piped water and sewerage networks serves to increase the vulnerability of residents to water-related climate change impacts. Efforts will center around improving access to water, sanitation, and wastewater disposal services across 10 cities, while also reducing pollution and CO₂ emissions.

India’s first solar-powered sewage treatment plant will be installed in Coimbatore on a pilot basis, and connected with more than 2,800 kilometers (km) of new sewage collection pipelines. Wastewater reuse for industrial purposes will also be made possible by advanced treatment facilities and the flood resilience of the systems will be increased through improved drainage and the raising of critical infrastructure.



Smart water management systems will also be installed, with 1,500 km of water supply distribution systems. Along with 40 new water storage reservoirs, this will provide residents with a reliable source of water, and the introduction of 110 district metered areas will reduce non-revenue water loss in water-scarce regions.

$503 million in funding and technical assistance are provided by ADB and Asian Clean Energy Fund.

Less than half of households in Tamil Nadu are currently served by piped water and sewerage networks (photo by ADB).

The Challenge

Rapid urbanization has been accompanied by infrastructure deficits, polluted waterways, and increased vulnerability to droughts and urban floods.


Health The absence of sewerage systems in project areas poses a major health risk, which improved infrastructure will help mitigate.

Social The program will directly address water, sanitation, and drainage service gaps amongst disadvantaged and underserved communities, including in slums.

Environment Improved sanitation and wastewater management will reduce contamination and ensure that residents have access to a clean water supply.