China's First Market Trade of Reclaimed-Water Carbon Reduction Credits Lands in Guangzhou with 3,351 Tonnes Traded

According to the Guangdong Provincial Department of Water Resources and under the guidance of the National Water Conservation Office, Guangzhou has recently completed China's first market-based trade of carbon reduction credits from reclaimed-water reuse, monetising 3,351 tonnes of water-saving carbon reductions. It marks the first time the ecological benefit of carbon reduction from wastewater reuse has been converted into value through market mechanisms, filling a gap in market trading of reclaimed-water conservation credits and turning an intangible water-saving value into a quantifiable, tradable carbon asset.

Water experts note that reusing treated wastewater for ecological replenishment and municipal miscellaneous uses directly substitutes for part of the tap-water supply, saving water while cutting energy consumption and carbon emissions across abstraction, treatment and distribution. To make this "invisible benefit" measurable and tradable, the National Water Conservation Office and the Guangdong water department guided the preparation of the Guangzhou Carbon Inclusive Methodology for Reuse of Compliant Effluent from Wastewater Treatment Plants, which compares the carbon footprint of tap-water supply against that of wastewater reuse systems to precisely account for the reductions, technically linking water conservation with carbon savings.

Using this methodology, Guangzhou systematically accounted for reclaimed-water reuse projects at central-district water reclamation plants in 2025, producing a first batch of 6,051 tCO2e of voluntary emission reductions, which were donated free of charge to the Guangzhou organising committee of the 15th National Games to support a "carbon-neutral" event.

The provincial department then pushed these credits toward market trading. Following the methodology, carbon reductions from reclaimed-water reuse by Guangzhou Water Investment's reclamation subsidiary were calculated at 5,577 tCO2e, published by the Guangzhou ecology and environment bureau and certified as Guangzhou Carbon Inclusive Emission Reductions (GZCER). Listed publicly on the Guangzhou Emissions Exchange, the seller (Guangzhou Water Investment) completed a trade of 3,351 tonnes with three corporate buyers including Hongchuang Science Park.

Proceeds from the trade will be earmarked for operation and maintenance of reclaimed-water reuse facilities, water-saving retrofits and R&D on low-carbon water technologies, forming a "conservation — carbon quantification — market value — reinvestment in conservation" loop. By quantifying an environmental value beyond the water tariff, the trade opens a market channel for green value and is expected to draw more private capital into water-saving retrofits and the water-saving industry.

Next, the Guangdong Provincial Department of Water Resources will promote the experience and explore a provincial-level carbon inclusive methodology for reclaimed-water reuse.