Closing the loop: ‘Water we doing on reuse?’

Water crises are making headlines worldwide—whether it’s too little, too much, or too polluted. Over 4 billion people already experience water scarcity, including 1 billion in urban areas. By 2050, the number of urban residents facing water scarcity is projected to double. 

At the same time, over 80% of wastewater globally is discharged into local water bodies without treatment. This has wide-ranging implications for pollution, human health, and biodiversity protection. Climate change compounds these challenges, with wastewater systems contributing 7% of global methane emissions. 

Water reuse offers a solution—reducing water scarcity, pollution, and emissions, while making the supply of water more reliable. Yet, global reuse capacity remains below 250 million cubic meters per day, accounting for just 8% of total freshwater withdrawals for domestic and industrial use. 

With technological solutions available, why is water reuse not taking off faster? What lessons can we draw from of those who have solved the puzzle? 

Here are three cases demonstrating how cities and industries are advancing water reuse—and how the World Bank’s 2030 Water Resources Group (WRG) is making it a priority. 

1. Singapore: Comprehensive Approach to Reuse

Singapore has taken a proactive, strategic approach to water reuse. NEWater, or treated wastewater, is one of the country’s four main water sources, alongside imported water, water from the local catchment, and desalinated water.  NEWater has enabled Singapore to close the water loop, presenting a sustainable solution to the issue of water scarcity. 

Most NEWater is used by industries, including wafer fabrication, power generation, petrochemical units, and public and commercial cooling systems. 

With industrial demand projected to account for two-thirds of Singapore’s growth in water demand by 2065, long-term infrastructure planning is critical. The government is developing a three-node used water management system, anchored by the Deep Tunnel Sewerage System. This will convey used water to centralized water reclamation plants across Singapore. To further manage demand, Singapore has introduced mandatory water recycling requirements for new projects in water-intensive non-domestic sectors such as wafer fabrication, electronics, and biomedical industries.

2. São Paulo, Brazil: Industrial Reuse at Scale

Aquapolo, Latin America’s largest water reuse project, produces up to 1,000 liters per second of recycled water for industrial purposes. A partnership between Sabesp, Brazil’s largest water supply and sanitation company, and GS Inima, the facility treats secondary sewage from Sabesp’s wastewater treatment plant to meet the quality standards required by petrochemical industries. A 17 km pipeline supplies the treated water directly to customers. Aquapolo helped industries endure two of the region worst droughts (2014-15 and 2021) while reducing pressure on drinking water supplies.

A key factor in Aquapolo’s success has been long-term purchase agreements, securing industrial commitments to buy recycled water through 2054. This model provides investment certainty for wastewater treatment infrastructure while increasing sewage collection, meeting growing industrial water demands, and reducing the pressure on drinking water supplies for households. 

3. Corporate Leadership in Reuse

Industries are increasingly integrating water reuse into their operations and supply chains, particularly in high water-stress regions. Companies in electronics, textiles, and food production are setting reuse targets and investing in closed-loop systems to reduce freshwater demand.

Some technology firms have introduced supplier programs to incentivize water management improvements. For example, Apple’s Supplier Clean Water Program prioritizes reuse in high-risk areas, aiming for a 50% reuse rate by 2030. By 2023, it had engaged 246 supplier facilities, saving 76 billion gallons of water since 2013.

Likewise, major textile and apparel brands are adopting closed-loop water systems, while food and beverage manufacturers are expanding on-site water recycling to reduce intake and meet regulations. These corporate efforts, alongside industry-wide initiatives and regulatory incentives, are helping scale water reuse globally.

Accelerating Water Reuse: The Role of the World Bank

While these examples demonstrate progress, much more remains to be done to make water reuse a widely accepted practice. 

WRG is working to accelerate reuse by strengthening the economic case and fostering collaboration. In partnership with Global Water Intelligence and the International Finance Corporation, WRG is articulating the economic, social, and environmental benefits of reuse, along with the enabling conditions required to scale reuse efforts at the national, city, and corporate levels. 

A core focus of this work is developing market-based incentives for reuse. One such mechanism is wastewater reuse certificates, conceptualized by WRG. Drawing on lessons from emissions trading schemes and carbon markets, this approach enables users who exceed reuse targets to generate credits that can be traded with entities falling short. By shifting beyond compliance-driven models, which have faced challenges in achieving large-scale adoption, particularly in some developing country contexts, this system creates a financial incentive for broader adoption. WRG is currently piloting this approach in India, alongside the development of a water reuse exchange platform. For more insights on water reuse, stay tuned for the upcoming World Bank Group report on “Scaling Water Reuse.”  

Water reuse offers a blueprint to make the water sector more sustainable. Closing the loop is within reach.