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Urban farming through treated wastewater offers a nature-based solution for reducing freshwater dependence, closing resource loops, and creating resilient communities.
Image Source: Getty
Food, water, and energy scarcities are no longer future threats but present urban realities. The pressing question is: how can cities turn this vulnerability into resilience? Cities consume about 80 percent of the world’s resources and generate 50 percent of global waste. They are also at the frontlines of climate change and are already grappling with scarcities in the critical food, water and energy sectors. With increasing climate-induced vulnerabilities, urban farming is a viable nature-based solution to enhance local food security and an avenue for the reuse of treated wastewater, thereby closing resource loops, reducing freshwater dependence, and strengthening urban resilience. Cities can embrace circular, climate-resilient development by linking food production with wastewater reuse.
Urban farming refers to the production, distribution, and marketing of food or non-food agricultural products within the geographical limits of a metropolitan area, including backyards, rooftops, vacant plots, and vertical gardens. Modern urban living and the commodification of food have created long supply chains offering little to no knowledge of the source, production process, and the embedded social and environmental costs of the food we consume. These supply chains are vulnerable to climate change disruptions, affecting food prices and causing the loss of agricultural land. Urban farming offers a tangible and climate-resilient way to link urban communities to a food production system from which they are increasingly alienated. It is a nature-based risk reduction strategy contributing to food sovereignty by decentralising food production, reducing dependency on external food sources, and buffering urban populations against supply shocks. Such a strategy can also help develop an environmental consciousness, foster healthy eating habits, and cultivate an informed, engaged, and ecologically rooted urban society.
Urban farming offers a tangible and climate-resilient way to link urban communities to a food production system from which they are increasingly alienated.
Historically, under the influence of capitalism and later neoliberalism, space has been segregated into urban and rural areas vis-à-vis their land use, leading to the perception that agriculture is a rural mainstay. With a rich history of subsistence, urban farming is challenging such binaries and gaining traction worldwide in city resilience planning. In Quito, Ecuador, the Participatory Urban Agriculture Project (AGRUPAR), launched in 2002, has successfully connected the entire food value chain with food justice, right to the city, and achieved food security. The project integrated indigenous and ancestral farming practices inherited from the pre-Columbian era (mainly cultivating potatoes, corn, broad beans, zambo, pumpkins, and beans) with technologies and innovations needed for urban farming. The project currently supports more than 2,200 urban orchards. In Chennai, India, the Chennai Urban Farming Initiative (CUFI) is scaling up vegetable gardening through a citywide strategy utilising acres of rooftops and vacant urban spaces while ensuring economic benefits for low-income neighbourhoods vis-à-vis greening and cooling the city.
Urban farming—in the form of green rooftops—not only mitigates the urban heat island effect but also supports stormwater management by reducing surface runoff through permeable surfaces. It can also significantly absorb waste streams such as grey water, kitchen waste, and treated toilet wastewater, reducing the burden on the city’s infrastructure.
Cities generate immense quantities of wastewater daily, much of which is inadequately treated, leaving a significant environmental footprint - polluting rivers, coastlines, and even oceans. For example, Mumbai generates about 2,190 million litres daily (MLD) of sewage, of which only 22.65 MLD is recycled for non-potable purposes. A circular climate-resilient urban system offers a pathway for cities to close the loop on material flows by reusing the waste produced as part of one process as a resource for another, whether on a scale of a city, a neighbourhood or a single household. Wastewater consists of grey water (water from sinks, washing machines, baths, and showers) and black water (effluent from toilets containing faeces and urine). At the household level, greywater recycling can supply water for terrace gardens, car washing, cleaning outdoor areas, and even washing solar panels. Such reuse reduces pressure on freshwater sources while enhancing nutrient cycling and promoting greater sustainable water use at home.
A circular climate-resilient urban system offers a pathway for cities to close the loop on material flows by reusing the waste produced as part of one process as a resource for another, whether on a scale of a city, a neighbourhood or a single household.
At the municipal level, large-scale sewage treatment plants often discharge treated water into rivers or the sea. Once it meets the required quality standards laid down by the Central Pollution Control Board, redirecting a portion of this water can support urban farms, green corridors, and agroforestry within city limits. However, ensuring compliance with safety standards is critical, particularly for pathogens, heavy metals, and salinity levels. Inadequate treatment poses serious risks, as seen in the Musi River basin in Hyderabad, where irrigation using partially treated wastewater led to heavy metal concentrations in crops cultivated there.
On the other hand, studies in the United States and Israel demonstrate that advanced water treatment and reuse systems that adhere to water quality standards and monitoring have successfully delivered a consistent supply of water for agriculture. In addition to saving water, these systems allow for the recovery and reuse of essential nutrients like potassium, phosphorus, and nitrogen. In 2004, the Karnataka State Pollution Control Board (KSPCB) issued a Zero Liquid Discharge (ZLD) order, requiring residential apartments with a built-up area larger than 20,000 square meters within sewered areas to install on-site Sewage Treatment Plants (STPs) and reuse their treated wastewater. Consequently, more than 2,200 on-site STPs were installed in the city, although there were wide variations in the quality standards and compliance levels.
Targeted incentives are important for this approach to be successful. Incentives may include decentralised wastewater treatment systems, tax benefits for industries and housing societies that recycle and reuse water, infrastructural support for connecting treated wastewater to urban farms or green spaces and performance-based incentives linked to water savings. Best practices like NEWater in Singapore and water reuse in Israel can offer potential lessons.
Adopting circular economy principles in urban water governance offers a transformative approach by treating water as a reusable asset. A circular water system can support urban farming and green infrastructure, making cities climate-adaptive and resilient. However, the success of such a system depends on a robust policy and regulatory framework.
Urban farming that leverages treated wastewater should be woven into the fabric of urban planning as a core strategy for building climate-resilient and circular cities of the future.
India’s National Mission on Food Security (2007) and the National Mission for Sustainable Agriculture (2010) have introduced sustainable technologies and stakeholder collaboration to promote sustainable agriculture practices. The Smart Cities Mission and Atal Mission for Rejuvenation and Urban Transformation (Amrut) 2.0 have also emphasised multifunctional land-use planning, urban heat reduction, and ecological balance. At the state level, programmes such as the Mission for Integrated Development of Agriculture in Telangana, Vegetable Development Programme in Kerala, Urban Horticulture Development Scheme in Tamil Nadu, and Rooftop Gardening Subsidy Scheme in Bihar have promoted urban farming through subsidies for rooftop farming, capacity building and ‘Do-it-yourself Kits’ for vegetable production.
Despite these initiatives, urban farming is found to be peripheral in state-level policies. For more holistic implementation, cities must move beyond fragmented efforts and policy silos, and root for an integrated policy landscape. Urban farming that leverages treated wastewater should be woven into the fabric of urban planning as a core strategy for building climate-resilient and circular cities of the future. Such holistic outcomes necessitate multi-stakeholder coordination and binding regulations for wastewater treatment and reuse, establishing safety standards, especially regarding pathogens, heavy metals, and salinity. The Residents’ Welfare Associations (RWAs) must establish decentralised sewage treatment plants (STPs) and grey water recycling for rooftop farms - serving as an example of citizen-led stewardship.
At a time when cities find themselves at the critical crossroads of climate change, rapid urban development, economic inequality and challenges in service delivery, urban farming through treated wastewater offers a paradigm shift by imagining waste as a resource and communities as co-creators of resilience. It ushers in a new urban ethic that values circularity, equity, and socio-ecological balance and strives for a regenerative urban future. The time has come to scale beyond pilot projects into municipal master plans and state-level visions backed by financing and regulatory standards, towards building climate-resilient, inclusive and circular cities of tomorrow.
Soma Sarkar is an Associate Fellow with the Urban Studies Programme at the Observer Research Foundation.
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Soma Sarkar is an Associate Fellow with ORF’s Urban Studies Programme. Her research interests span the intersections of environment and development, urban studies, water governance, Water, ...
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