en.Wedoany.com Reported - Bangalore International Airport (BIAL) has partnered with engineering consultancy Walter P Moore to develop a "water positive" rainwater harvesting system that collects and reuses rainfall runoff from the airport's extensive impermeable surfaces, reducing reliance on a single municipal water source while supporting groundwater recharge in surrounding areas.
Airports are among the most water-intensive infrastructure systems, requiring substantial water resources for passenger services, cooling, landscaping, and fire protection. Located in one of India's fastest-growing metropolitan regions, BIAL faced increasing water demand compounded by regional water scarcity, prompting the search for a more resilient water strategy. Runways, taxiways, and aprons form vast impermeable surfaces that generate significant runoff during rainfall events. The design team helped develop a coordinated system of retention ponds, bioswales, and underground storage tanks to integrate runoff into the airport's operational water supply, thereby reducing pressure on municipal sources, supporting aquifer recharge, and improving on-site stormwater management.
The design process began with a detailed assessment of the airport's multiple drainage basins to understand how water could be collected, stored, and reused across the site. The team used historical rainfall data and hydrological models to estimate rainwater harvesting potential under dry, average, and wet conditions, helping optimize system size and performance. To address future uncertainties, projections such as SSP5-8.5 (a high-emission climate scenario) were applied, calculating climate change factors for specific design storms to assess long-term variability and water supply risks. These analyses collectively informed stormwater management strategies, directing runoff to storage and recharge systems while safely discharging excess flows. The final system design is adaptable to both current conditions and evolving climate pressures.
Simplicity and efficiency guided key design decisions. Retention ponds were connected by gravity, reducing reliance on pumps and mechanical controls, thereby lowering energy demands and operational complexity. Storage capacity was further enhanced through the use of riser weirs, enabling ponds to serve multiple functions without expanding their footprint. These strategies achieved dynamic utilization of available storage while maintaining operational reliability, meeting daily water needs and enhancing long-term resilience.
Currently, BIAL meets most of its water demand through collected rainwater and recharged groundwater, significantly reducing reliance on municipal supply. The system lowers operational costs, enhances water security during drought periods, and contributes to raising groundwater levels in surrounding areas, benefiting nearby communities. The collaboration between BIAL and Walter P Moore demonstrates that large airports can be transformed into "water positive" systems through strategic planning, engineering innovation, and climate-adaptive design. Rooted in management, this project balances operational needs with ecosystem health, setting a benchmark for water resilience in future global projects.
