ICLEI South Asia: Green-grey infrastructure for urban resilience

In Kochi, a city on the coast of Kerala, India, canals historically provided irrigation, fishing, recreation and transportation. Today the canals remain a major site of economic activity, including tourism, and serve as infrastructure for climate resilience. With time, however, urban growth, neglect and illegal dumping have left many canals dormant and toxic, negatively impacting residents’ quality of life, health and livelihoods. Another effect of limited to no planning and maintenance is poor water quality, which has contributed to a rise in serious water-borne diseases such as E. C-oli infection, hepatitis A, dysentery and leptospirosis.

Extreme flooding finally drew attention to the canals’ dire state. With the oversight of the Kochi Municipal Corporation, several of the main canals are currently under restoration. Notwithstanding the recognised potential of nature-based solutions to mitigate risks such as flooding, the overall strategy, plan and activities do not take a nature-based approach. Increased interest in Fort Kochi has presented city officials with an opportunity to rethink, reorient and retool the canal restoration.

The approach 

This project will test within the context of Kochi’s canal restoration effort the scalability and benefits of nature-based solutions such as planting mangroves, wetland construction, and using porous surfaces for canal walls in combination with traditional components such as small-scale, strategically placed breakwaters, small dikes and wood fencing. The expected benefits of this integrated approach include greater protection against floods, lower toxicity levels, improved water quality, absorption of micropollutants and other compounds, mitigation of urban heat and diversification of livelihoods, for example, through eco-tourism.

Such “green-grey” infrastructure solutions depend on the cooperation of the public and private sectors and local communities. The Kochi government provides long-term planning and resources to create an environment conducive to implementation. NGOs, civil society and communities help ensure the social acceptance, adoption and inclusion necessary to deliver green-grey infrastructure in a sustainable manner; thus, the project also encompasses social marketing to encourage residents to keep canal waters clean and clear of waste. The private sector brings efficiency, innovative products, technology and expertise to help reduce the project’s technical risks and to enhance outcomes and benefits.

Goals and achieved impact 

The goal of the project was to scale the integration of nature-based solutions into conventional infrastructure development for the restoration of Fort Kochi’s canals. The intended community benefits included better health outcomes, increased tourism, and greater resilience against extreme flooding. The project aimed to develop a design standard for green-grey infrastructure, combining techniques from conservation, materials science, and engineering.

A detailed baseline assessment identified Pandarachirathodu canal as the study site. The report presents a conceptual design for green-grey infrastructure, focusing on six aspects: Canal Works, Sewage Treatment, Waste Management, Green Infrastructure, Others, and Financial Stability. Recommendations were categorized into short, medium, and long-term interventions, with a budget of USD 5 million for short-term actions.

Our partner 

ICLEI South Asia is a not-for-profit organisation registered under the Indian Trusts Act. It works in the sectors of urban biodiversity, sustainability, energy and climate and mobility, with a team of over 60 professional staff, including urban planners, energy managers, environmental planners, transportation engineers, ecologists and environmental engineers.

ICLEI is supported by Bechtel.org, a social enterprise by Bechtel Corporation supporting know-how sharing and innovation to help communities build better and grow stronger.

Relevant links:

Kochi Smart Canal: Final Report

ICLEI– Local Governments For Sustainability, South Asia

Bechtel

The copyright for all images displayed lies with ICLEI South Asia.