City of 1,000 Tanks

Creation of semi-natural blue areas, Management and improved protection of rivers and other blue areas, Strategy, plan or policy development

The "City of 1,000 Tanks" pilot project, is looking to achieve a closed-loop water system that will make communities and properties self-sustaining in the decades to come (Ref. 8). Specific project objectives include: - Providing solutions for floods, water scarcity and pollution in Chennai; - Developing a 'Water Balance Model' across the city by collecting rainwater, treating wastewater and runoff pollution with decentralised nature-based Solutions and recharging the underground aquifer; - Preventing droughts and saline intrusion due to sea-level rise and reduce the risk of floods and sewage pollution to ultimately improve the water supply capabilities of the city; - Mitigating risks associated with high-frequency floods as well as sewage pollution; - Fixing supply-side issues by creating water retention and supply capabilities; - Resurrecting the city’s historical system of water tanks as part of a holistic solution to the problems of flooding, water scarcity and pollution. (Ref. 1,6) The project also envisions improving the engagement, awareness and participation of locals by involving communities living in the localities where the project is being implemented through programs like Water Literacy (Ref. 3, 4) (Ref. 3,4)

The project plans to use temple tanks, bio-swales, renaturalization of rivers and canals, constructed wetlands for diffused pollution, constructed wetlands for sewage treatment, detention parks, floating islands, rainwater harvesting, recharge wells, solid waste management, agro-forestry as tools for providing a holistic solution to water problems of the city (Ref 5). The project will be implemented through the involvement of the public and private sectors, technicians, and citizens (Ref 2), and has an important focus on improving water literacy with children from informal and low-income settlements across Chennai (Ref. 3, 4). Specific activities include: -Implementation of a water literacy programme for children from informal and low-income settlements across Chennai. As a result, over 150 children from 10 settlements have been identified as potential ‘water ambassadors’ who will raise awareness related to water conservation in their areas (Ref. 3). -Launch of a social media campaign: published a combination of completed activities with designs created for future projects and discuss the past, present and future of water in Chennai through a 6-part animation film series prepared in Tamil and English (Ref. 3). - Linking historic tanks, canals and rivers into a new green network of bio-swales, constructed wetlands and water detention ponds (Ref. 5). - In one of the project pilot locations, Little Flower Convent, the efficacy of Nature Based Systems to treat wastewater using advanced septic tanks and constructed wetlands has been showcased, in which the treated water is then discharged through a network of underground irrigation pipes to recharge and augment the aquifer locally while sustaining gardens that contribute to urban cooling. Here, "27,000 liters of the wastewater generated by 300 residents are being treated and discharged every day. " (Ref. 9). In the context of developing holistic water solutions in Chennai, the project considers spatial, technical, organizational, cultural, and economic challenges. This is achieved through a staged and adaptive reform of the current water management system to utilize Chennai’s water resources better. Four areas (Mylapore, Chitra Nagar, Mambalam, and Koyambedu) are addressed in the context of their unique water challenges (Ref. 10). Proposal 1: Mylapore Heritage Programme: This system is comprised of connected ponds and temple tanks that retains water during monsoons for use in the dry season each year. Proposal 2: Chitra Nagar Disaster-Resilient Housing Programme" “In this proposal, the water loop is closed in Chitra Nagar housing scheme by retrofitting systems for water collection, recycling and recharge, as well as solid waste management. The structural changes provide residents with a reliable and clean water source and prevent chronic flooding and standing water.” (Ref. 10). Proposal 3: Koyambedu Green Industries Programme: "This proposal protects the Koyambedu region from future water impacts by installing stormwater absorption measures and creating a solid waste recycling program.” (Ref. 10). Proposal 4: Mambalam Smart Waterways Programme: “This proposal capitalizes on the area's high visibility as a commercial center to demonstrate the efficacy of NbS tools in collecting, cleaning, storing and recharging water in a variety of public and private spaces” (Ref. 10).

• Local government/Municipality
• Public sector institution (e.g. school or hospital)
• Citizens or community groups