In the 21st century, water has become the true limit of our development. While the climate crisis accelerates longer droughts, more extreme floods, and unpredictable hydrological patterns, the availability of freshwater is decreasing at an alarming speed. Globally, more than 2 billion people live in water-stressed areas, and the gap between supply and demand threatens to reach 40% by 2030. In China, the challenge is felt with particular intensity in strategic regions such as Xi’an, where urban expansion, industrial demand, and technological innovation compete for an increasingly scarce resource. This context demands bold solutions capable of transforming vulnerability into resilience and ensuring that water is not a limit but a driver of prosperity.
Phase II of the Xi’an Aerospace City Water Plant is not just a capacity expansion; it is a paradigm shift. The facility increases total capacity to 350,000 m³/day (300,000 m³/day in the new underground plant) through a state-of-the-art treatment train that integrates pretreatment (fine screens and grit removal), coagulation–flocculation, advanced sedimentation with lamella clarification, V-type filtration, membrane ultrafiltration, and final combined disinfection with UV + hypochlorite. This is complemented by balancing tanks, interconnection with a dedicated reclaimed water network for industrial and urban uses, and a sludge management line with thickening and dewatering compliant with regulations. Operations are controlled through SCADA and IoT, guaranteeing physical and digital traceability in real time. The result is decisive: >36 million m³/year of reclaimed water, over 90% reduction of BOD5 and total suspended solids, >99.9% removal of coliforms, and strict compliance with international reuse standards (WHO, ISO 14001/46001, Chinese Class 1A reuse/effluent standards).
The contrast with the baseline situation is radical. Before, the Wei River basin lost more than 25 million m³/year, whereas today more than 36 million m³/year are regenerated and certified. This means fewer extractions from overexploited aquifers, less pressure on receiving water bodies, and water availability that multiplies the resilience of the aerospace industrial hub and the surrounding urban fabric. The benefits are measured in three dimensions: environmental (improvement of the chemical and ecological status of the basin), social (reduced health risks and greater supply security during droughts), and economic (savings from replacing freshwater, reduced regulatory penalties, and operational stability for high-tech clusters).
The project aligns explicitly with the Water Positive strategy and with the principles of additionality, intentionality, and traceability defined by the VWBA 2.0 framework. Each regenerated cubic meter is accounted for as an additional and auditable Volumetric Water Benefit (VWB), and each quality improvement is supported by emerging Water Quality Benefit Accounting (WQBA) methodologies. This strengthens the social license to operate, projects ESG leadership within frameworks such as ESRS E3, Science Based Targets for Water, CEO Water Mandate, and Net Positive Water Impact, and generates confidence among investors and offtakers. Digital traceability and verifiable reporting not only demonstrate results but also convert them into strategic assets for the water benefits market.
Its replication potential is supported by a modular, scalable design governed by public–private cooperation schemes with external verifiers. This model is transferable to other urban and industrial basins in China and globally, where water pressure demands immediate solutions. Ultimately, the Xi’an Aerospace City Water Plant represents a precedent for next-generation water infrastructure: it not only secures the water balance of the Wei River basin but also inaugurates a vision of a regenerative water economy, where every lost drop is transformed into opportunity and collective resilience.
Xi’an faces a scenario of severe water stress. The Wei River basin, where the project is located, presents a structural deficit: water withdrawals exceed natural recharge, groundwater levels continuously decline, and drought episodes are increasingly frequent. Added to this is the point-source pollution from industrial discharges and the insufficiency of existing infrastructure, compromising both urban supply and the competitiveness of strategic sectors. This combination of factors makes water an economic, social, and environmental risk of the highest order.
Phase II of the Water Plant transforms this challenge into a concrete opportunity. With its 300,000 m³/day capacity, it will recover more than 36 million m³ annually of reclaimed water, substituting direct withdrawals and reducing polluting discharges. In the short term, the benefit is reflected in the immediate availability of safe water for the aerospace, technology, and urban sectors. In the medium term, the city will gain operational efficiency, reduced costs, and compliance with stricter environmental regulations. In the long term, Xi’an will be able to sustain industrial and population growth without mortgaging the region’s water future.
The model is replicable in other industrial and urban hubs subject to water stress. Its scalability lies in the integration of cutting-edge technologies (ultrafiltration, advanced membranes, UV disinfection, process digitalization) with participatory governance and external verification certifying the benefits. For companies with ESG commitments, Science Based Targets for Water, or alignment with Net Positive Water Impact, joining such a project is not only about meeting a target: it is about leading a narrative of transformation, visibility, and competitive differentiation.
The technical core of the project is a treatment train combining advanced sedimentation, V-type filtration, membrane ultrafiltration, and disinfection with UV and hypochlorite dosing. This hybrid solution was selected after evaluating alternatives such as artificial wetlands and conventional secondary systems, prioritizing efficiency, resilience, and compliance with international standards (WHO, ISO, Chinese and European legislation). Its nominal capacity of 300,000 m³/day covers Xi’an’s growing demand and ensures a robust supply.
Quantifiable benefits include over 36 million m³ of reclaimed water per year, contaminant reduction, freshwater abstraction savings, and public health improvements by lowering exposure risks to effluents. Environmentally, the Wei River basin is protected, and pressure on aquifers is reduced. Economically, the project reduces supply and treatment costs and offers companies tangible ESG compliance certification.
Identified risks include technological failures, hydrological variability, and social resistance to changes in water uses. These are mitigated through equipment redundancy, real-time IoT sensors, contingency plans, governance protocols, and transparent communication with communities. Predictive maintenance and continuous adaptation to climate scenarios ensure long-term resilience.
The model can be replicated in Chinese cities with similar water stress and global industrial hubs. Its competitiveness is based on positive cost–benefit, the ability to generate verifiable indicators under VWBA, and alignment with national and international water transition policies.
The project is implemented under a phased and adaptive approach that ensures both technical robustness and external validation. In the first phase (2019–2020), a comprehensive baseline diagnosis was carried out, measuring lost volumes, effluent quality, and basin risks. In the second phase (2020–2021), detailed design and engineering were developed, evaluating technological alternatives and defining the most efficient hybrid solution. The third phase (2021–2023) comprised the construction of underground infrastructure, installation of critical equipment, and integration of digital monitoring systems. The fourth phase (2023–2024) focused on commissioning, performance testing, and external verification audits. Finally, from 2024 onwards, the plant enters continuous operation with real-time digital monitoring, traceability reporting, and external validation under VWBA.
The selected technology responds to criteria of efficiency, resilience, and international regulatory compliance. The system includes flow meters, multiparameter probes, IoT sensors, SCADA platforms, and blockchain connection, enabling digital traceability and auditable reports. Its nominal capacity of 300,000 m³/day guarantees the regeneration of more than 36 million m³ annually, equivalent to the consumption of an entire urban district of Xi’an, radically transforming local water availability.
Key performance indicators include volume recovered, contaminant reduction (BOD, suspended solids, coliforms), freshwater abstraction savings, avoided emissions, and resilience to drought events. These are measured with certified laboratory analyses, online sensors, remote sensing, and audited monthly reports. The comparison between with-project and without-project scenarios ensures transparency and robustness, aligned with VWBA methodology.
Governance involves active participation of the technical operator, regulatory authority, industrial beneficiaries, and accredited external verifiers. Each actor has clear roles in operation, maintenance, monitoring, validation, and communication of results. A preventive and corrective maintenance protocol, together with a continuous improvement plan based on data feedback and technological updates, ensures permanence and scalability of water and environmental benefits over time.
Phase II of the Xi’an Aerospace City Water Plant expands and modernizes total capacity to 350,000 m³/day (300,000 m³/day in the new underground plant), with a high-efficiency treatment train that integrates pretreatment (fine screens and grit removal), coagulation–flocculation, advanced sedimentation/lamella clarification, V-type filtration, membrane ultrafiltration, and final combined disinfection with UV + hypochlorite. The system incorporates balancing and regulation tanks, interconnection to a dedicated distribution network of reclaimed water for industrial (cooling towers, processes, services) and urban (irrigation, street cleaning, ornamental) uses, and a sludge line with thickening and dewatering for safe disposal in compliance with regulations. The entire process is governed with SCADA and IoT, ensuring real-time traceability of flow and quality. The intervention enables recovery of >36 million m³/year, reduction of BOD5 and TSS by >90%, coliform removal by >99.9%, and compliance with reuse and discharge standards (WHO, ISO 14001/46001, and national Class 1A reuse/effluent standards), enabling safe and controlled reuse.
The relevance is double and measurable: it resolves a structural water deficit in the Wei River basin and converts losses and pollution into availability and resilience for the city and its aerospace industrial hub. Compared to the baseline, the leap is clear: from losing >25 million m³/year to regenerating >36 million m³/year with certified quality, reducing extractions from overexploited aquifers and pollutant loads to receiving bodies. This translates into environmental benefits (better chemical and ecological status, less pressure on groundwater), social benefits (lower health risk, more secure supply in droughts), and economic benefits (savings from replacing freshwater, reduced exposure to sanctions/regulations, operational stability for critical clusters).
The strategic value is anchored in its demonstrable contribution to the Water Positive roadmap: it delivers additional, intentional, and traceable Volumetric Water Benefits (VWBs) under VWBA/WQBA, strengthens the social license to operate, and elevates ESG performance within frameworks such as ESRS E3, Science Based Targets for Water, CEO Water Mandate, and Net Positive Water Impact. For investors and offtakers, it offers compliance assurance, a leadership narrative, and competitive differentiation based on auditable metrics (m³ regenerated, assured quality, avoided emissions). Replicability is supported by technical criteria (membrane modules, automation, continuous monitoring), by public–private governance with third-party verification, and by reclaimed water demand contracts; this facilitates scaling to other urban and industrial basins in China and abroad. The final impact is tangible: contribution to the water balance of the Wei River basin, greater local climate resilience, and an exportable precedent of how next-generation water infrastructure drives a truly regenerative water economy.
