Suggested citation: TMC and CEEW. 2025. Treated Used Water Reuse Plan for Thane City. Thane: Thane Municipal Corporation; and New Delhi: Council on Energy, Environment and Water (CEEW).
The Treated Used Water (TUW) Reuse Plan for Thane City was developed by CEEW in association with the Thane Municipal Corporation (TMC). This first-of-its-kind plan aims to maximise the safe reuse of TUW, enabling a circular economy approach to (domestic) used water management in TMC. It promotes TUW reuse for non-potable purposes and establishes reuse–specific quality standards to ensure its reusability. This can reduce the city’s dependence on freshwater to meet its growing water demand, prevent the misuse of groundwater resources, and improve the quality of local water sources.
The plan sets city-specific targets for 2035 and 2046 to optimise sewage treatment capacity utilisation, upgrade sewage treatment infrastructure with advanced technologies, and maximise the safe reuse of TUW. It estimates the financial requirements and identifies reuse-specific business models to meet these targets. The plan also establishes a zone-wise implementation strategy, mapping treated water reuse zones to ensure efficient allocation and conveyance of TUW to identified users.
Key highlights
Water security is crucial for the sustainable growth and resilience of economies. Managing freshwater demand should be India’s foremost priority in achieving water security, considering that 11 out of the 15 major river basins in the country will be water-stressed by 2025 (Bassi, Gupta, and Chaturvedi 2023). The situation is particularly severe in urban areas where scarce freshwater resources are unable to keep up with the growing water demand. Given the quantum of domestic used water generated in Indian cities, once safely treated and reused, it can serve as a highly valuable resource that can reduce the pressure on freshwater resources and improve the quality of rivers and aquifers. However, only 30 per cent of the domestic used water generated by Class I and II cities (population above 50,000) is treated (CPCB 2021). Further, the reuse of treated used water is very low, even in the major urban agglomerations in the country (Bassi, Gupta, and Chaturvedi 2023). Hence, it is essential to empower urban local bodies (ULBs) to formulate and adopt long-term reuse plans with clear targets for used water treatment and reuse – an element currently missing in Indian cities.
The Treated Used Water (TUW) Reuse Plan for Thane City was developed by CEEW in association with the Thane Municipal Corporation (TMC). This first-of-its-kind plan aims to maximise the safe reuse of TUW, enabling a circular economy approach to used water management in TMC. It promotes TUW reuse for non-potable purposes and establishes reuse – specific quality standards to ensure its reusability. This will reduce the city’s dependence on existing freshwater resources for non-potable purposes, optimise resource efficiency, and improve the water quality of local water sources in Thane City.
The Reuse Plan sets quantifiable targets for 2035 and 2046 for enhancing treatment capacity utilisation, upgrading existing treatment infrastructure – mainly treatment technologies – and maximising the safe reuse of TUW in Thane City. Local authorities must align their efforts and resources towards achieving these time-bound benchmarks.
We studied Thane’s water and used water scenario over the years and devised long-term strategies for efficient used water management to create the TMC Reuse Plan. The plan considers used water as an important asset and an essential component of water resources management. The overall approach adopted to develop the plan is illustrated in Figure ES1. TMC officials were consulted throughout the development process, and over 20 consultations were carried out.
Figure ES1: Nine-step approach for developing the TMC Reuse Plan
The Reuse Plan has identified potential reuse avenues or users of TUW within Thane City, along with corresponding departments within TMC that oversee these areas (Figure ES2). Further details regarding the roles and responsibilities of the relevant departments in TMC are provided in Section 13.1 (Table 22b). The end use will determine the quantity of TUW required and the quality parameters that the TUW will need to meet, further influencing the design of treatment systems and, in particular, the treatment technologies required.
Figure ES2: Identified TUW reuse avenues and stakeholders in TMC
Based on this, the plan recommends the following areas of action for effective TUW reuse planning and implementation:
Figure ES3: Five demarcated sewage zones within TMC for zone-wise reuse planning
Figure ES4: By 2046, no discharge of untreated domestic used water is targeted in TMC
The TMC Reuse Plan has been developed as a long-term guiding document for sustainable used water management in Thane City. It aligns with national and state guidelines for domestic used water treatment and reuse. The national Atal Mission for Rejuvenation and Urban Transformation 2.0 targets meeting 20 per cent of municipal water demand through TUW by 2025-26. Additionally, Maharashtra’s Treated Water Reuse and Management 2023 (Draft) Policy aims to replace 30 per cent of municipal freshwater use with TUW by 2025. The responsibility of implementing these policies lies with the ULBs, being the primary authorities for managing domestic used water in Indian cities. The TMC Reuse Plan provides a strategic framework and guidance to the ULB to strengthen used water management and implement TUW reuse projects within its jurisdiction. It sets city-specific targets that consider both the current and future water demand, factoring in the city’s planned development. This plan can be used as a template and provide direction to other cities to develop standardised reuse plans across the state. This is a crucial step for mainstreaming a circular economy in urban used water management.
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