Preparations are also underway at Liszt Ferenc International Airport to cope with heavy rainfall.

The European Union's CEF (Connecting Europe Facility) transport programme is providing funding for Budapest Airport to develop the airport's rainwater management infrastructure under the RESILIMET programme to develop the airport's rainwater management infrastructure. According to their announcement, the three-year project, which will start in early 2026, aims to ensure that the airport remains safe and sustainable in the long term despite the effects of climate change.

As part of the investment, drainage systems will be modernised, oil separation equipment will be expanded, and new rainwater storage solutions will be prepared to deal with extreme weather conditions.

A former mine pit became the airport's storm water retention pond.

Currently – available on the bud.hu website – a key element of the airport's rainwater management system is an artificial lake covering approximately 20,500 square metres, which was created on the site of a former material storage area about seventy years ago. The lake, which has no natural drainage, now serves as a storm water reservoir and fire water reservoir. In the 1980s, a separate system was built for sewage disposal, so since then the lake has primarily served to collect rainwater from the airport. With the expansion of the airport infrastructure, the proportion of paved surfaces has increased significantly, resulting in an increase in the amount of rainwater introduced, making it necessary to artificially regulate the water level and modernise the system.

Monitoring system protects receiving waters

The airport has a separate drainage system: rainwater from Terminal 1 flows into the airport's drainage pond and is then transferred in a controlled manner to the drainage system of Terminal 2, from where it is directed to the Maglódi Canal and ultimately to the Gyáli Stream. To protect natural waters, Budapest Airport operates two TOC monitoring stations. Their task is to measure the organic matter content of rainwater. If the concentration exceeds the limit value – for example, due to substances generated during winter de-icing operations – the system automatically diverts the water into the sewage network. This prevents ecological damage to the receiving watercourses.

Completed and ongoing projects support the achievement of sustainability goals

Water management improvements are part of Budapest Airport's broader sustainability strategy. Eleven drinking fountains have been installed in Terminal 2 of the airport, allowing passengers to refill their own water bottles, reducing the use of single-use PET bottles. In line with its environmental policy, the operator has set a target of reducing its direct carbon dioxide emissions by more than 90 per cent by 2030 and achieving the highest level 5 certification under the Airport Carbon Accreditation scheme by that date. The RESILIMET project contributes to this climate adaptation and environmental protection effort by strengthening the airport's water infrastructure.