In India’s rapidly expanding cities, the journey of water does not necessarily end when it disappears down a drain. Increasingly, urban local bodies are treating used water not as waste to be discarded, but as a resource that can be recovered, treated and put to productive use.
This shift is becoming an important part of urban sanitation under the Swachh Bharat Mission-Urban (SBM-U), with Used Water Management (UWM) emerging as a key approach to treating wastewater, preventing untreated sewage from entering water bodies and enabling the safe reuse of treated water.
At the centre of this transition are Sewage Treatment Plants (STPs), which are turning wastewater management into an opportunity to conserve natural water resources and create new supplies for agriculture, industry, horticulture and urban services.
The approach is reinforced through Water Plus certification, which provides cities with guidelines for managing wastewater generated by households and commercial establishments. The certification requires wastewater to meet prescribed treatment standards before it is discharged into the environment.
The focus, however, extends beyond building treatment infrastructure. Urban Local Bodies are being encouraged to develop long-term, city-level plans for wastewater reuse, backed by clearly defined responsibilities and improved technologies.
The Open Defecation Free (ODF)++ protocols further strengthen this framework by assessing the safe management and treatment of the entire sewage chain, including faecal sludge and septage.
Together, these measures are pushing urban sanitation towards a more circular model in which water is recovered and reused instead of being treated as a one-time resource.
Under SBM 2.0, projects worth ₹11,785 crore have been approved for setting up sewage treatment plants in small cities. These projects are expected to add 4,900 million litres per day (MLD) of treatment capacity, strengthening the infrastructure required for large-scale used water management.
From treatment to reuse
The changing approach is visible across cities that are developing wastewater systems suited to their local needs, infrastructure and water requirements.
Treated water is increasingly being used for irrigation, horticulture, industrial processes, road cleaning and lake rejuvenation. Cities such as Jaipur, Indore, Surat, Navi Mumbai and Tirupati demonstrate different ways in which treated wastewater can be integrated into urban economies and services.
Jaipur: Treating 215 MLD of sewage
Jaipur’s Dehlawas Sewage Treatment Plant represents one of the larger efforts to treat and reuse wastewater in the state.
Built across 22.50 hectares between 2020 and 2023, the plant has a treatment capacity of 215 MLD, making it the highest-capacity sewage treatment plant in Rajasthan.
The facility is fully automated through a Supervisory Control and Data Acquisition (SCADA) system and uses a highly efficient Sequencing Batch Reactor (SBR) process.
Wastewater passes through a Parshall flume, primary clarifier and treatment basin before reaching the chlorine tank, where it is converted into treated water. Solid waste is separated through primary sludge thickeners and screw press machines.
The treated water is being reused for irrigation and industrial processes. A portion is supplied to a nearby colony for gardening and other purposes, while the remaining treated water is discharged into the Dravyavati River.
Measures are also being taken to prevent untreated wastewater from reaching the river.
The plant site itself has been developed with a green area containing more than 30,000 plants, adding an environmental dimension to the facility.
Indore: Keeping untreated wastewater out of the environment
Indore’s transformation began with a straightforward objective: prevent untreated wastewater from reaching the environment.
The approach helped the city become the first to receive Water Plus certification, and its model has subsequently encouraged smaller cities to adopt similar practices.
Today, the city reports that no untreated wastewater flows through its rivers or natural and man-made stormwater drains.
By 2020, Indore had established seven decentralised STPs in addition to three existing centralised STPs. The city had also laid more than 200 kilometres of piped network to carry treated wastewater.
Wastewater management has been accompanied by efforts to conserve both groundwater and surface water. In 2022, more than 1.25 lakh rainwater harvesting units were installed across residential and non-residential areas within just four months.
Treated wastewater is now being used for water gardens, roadside plantations and horticulture. It is also used for washing roads and cleaning sewer machines.
The Indore experience illustrates how wastewater management can be integrated with broader urban water conservation rather than being treated as a standalone sanitation activity.
Surat: When wastewater acquires economic value
Surat has taken the reuse model a step further by treating wastewater as a resource with economic value.
The Surat Municipal Corporation has established four tertiary treatment plants with a combined installed capacity of 116 MLD.
The plants have reduced the city’s dependence on freshwater by supplying treated wastewater for a range of non-potable uses.
These include industrial applications, lake rejuvenation, agriculture, mass plantation and sewer cleaning. Treated water is supplied through dedicated service lines as well as tanker filling stations.
The city has also strengthened the maintenance of its sewerage infrastructure. Surat operates 170 sewer-cleaning machines, including equipment based on advanced robotic technology.
The model demonstrates how treated wastewater can become part of the city’s utility network while reducing pressure on freshwater sources.
Navi Mumbai: Reuse integrated into everyday city services
Navi Mumbai has combined wastewater treatment infrastructure with extensive reuse of treated water.
The city is the only city in Maharashtra to achieve a five-star rating and Water Plus certification.
Its sewage treatment technology has been upgraded, with STPs designed to serve a population of 30 lakh. Pumping stations have also been upgraded to reduce energy costs while transferring sewage to treatment facilities.
Preventive maintenance of the sewer network has been undertaken to avoid problem areas, while the city has achieved 100 per cent mechanised cleaning of sewer lines and septic tanks.
The Navi Mumbai Municipal Corporation centrally monitors septic tanks through Level Transmitters installed across the city.
More than 30 per cent of treated water is reused in over 30 city gardens. Treated water is also used for washing solid-waste vehicles, compactors and city transport buses. Sprinklers and road dividers use treated water as well, reducing the demand for freshwater for routine municipal activities.
Tirupati: Turning treated water into a revenue stream
Tirupati offers another model, combining wastewater reuse with revenue generation.
The city, which has also been declared Water Plus, operates a sewage treatment plant at Thukivakam built at a cost of ₹19 crore.
The plant has an installed capacity of 50 MLD and serves 1,04,057 households across the city.
Of the treated water generated, 24 MLD is reused for different purposes. The plant sells 5 MLD of treated used water to Srikalahasthi Pipes Ltd., generating a net revenue of ₹6 lakh per month.
Another 18 MLD is supplied free of cost to farmers for agricultural use.
The Urban Local Body also reuses treated water for road and street cleaning, as well as for watering road medians, parks and gardens.
By combining commercial sales, agricultural reuse and municipal applications, Tirupati has developed a model aimed at making the operation of its STP more financially sustainable.
From waste disposal to a circular water economy
The experiences of these cities point to a broader change in the way urban India is approaching water.
For decades, wastewater management was largely viewed through the lens of disposal – collecting sewage, treating it and preventing pollution. The emerging model adds another objective: recovering water and returning it to productive use.
The applications are diverse. Treated wastewater can support agriculture and horticulture, supply industrial processes, rejuvenate lakes, clean roads and maintain public spaces.
The shift also changes the economics of urban sanitation. Treatment plants can become sources of reusable water, while cities can reduce their dependence on freshwater supplies for activities that do not require potable water.
Under SBM-U and SBM 2.0, the expansion of treatment capacity, Water Plus certification and ODF++ protocols are helping create the institutional framework for this transition.
As cities expand and freshwater resources face increasing pressure, the idea of wastewater as a resource offers a different way to think about the urban water cycle: water does not have to become waste simply because it has been used once.
The emerging approach is to collect it, treat it, recover it and give it a second life – making urban sanitation not only cleaner, but more resource-efficient and increasingly circular.
