On 25 November 2025, we organized a professional visit on behalf of the General Directorate of Water Management of Hungary (OVF) to explore how Sri Lanka’s traditional Tank Cascade Systems (TCS) operate – one of the world’s oldest, smartest and most climate-resilient water-management solutions.
Our host was Prof. K. D. W. Nandalal, Ludovika Fellow at the University of Public Service (NKE), who introduced the unique logic of Sri Lanka’s cascades for us: interconnected small reservoirs built along natural drainage lines, reusing water multiple times, stabilising irrigation, and buffering both floods and droughts. Their ecological components – the Gasgommana windbreaks, Perahana filtration belts and Kattakaduwa salinity barriers – show that nature-based engineering was practiced long before the term existed. His system-level perspective was complemented by Prof. János Bogárdi, who linked these historical solutions to today’s global water-governance challenges.
During the visit, László Balatonyi presented Hungary’s water-management framework on behalf of OVF, offering a striking contrast. Hungary’s hydrology is fundamentally shaped by the fact that 96% of our surface water originates abroad, and our national protection system is built around large-scale flood-defence infrastructure. Today we maintain more than 4,300 km of primary flood-protection levees, – one of the most extensive systems in Europe – contributing to our remarkable safety record, with no fluvial flood casualties since the 1965 Danube ice flood.
A particularly relevant comparison point is the Tisza River system, where Hungary operates a highly sophisticated operational control and monitoring network. This modern system enables real-time water-level management, coordinated reservoir operation and early-warning functions across the entire Upper Tisza basin. It is a strong example of how digital water-management infrastructure can optimise flood protection and drought preparedness at basin scale – offering a technological counterpart to Sri Lanka’s cascade-based, nature-centred approach in the 21st century.
Yet the comparison also revealed parallels. While Hungary excels in basin-scale flood protection and high-tech water-operations management, we struggle with fragmented lake ownership, which often prevents the kind of coordinated water-sharing and seasonal storage that makes Sri Lanka’s cascades so effective. Still, there are promising Hungarian examples, such as the Rinya Channel pilot, where lake owners agreed to manage water together – showing that integrated micro-catchment governance is possible here as well.
The mutual lesson is clear: ancient systems and modern hydrology have much to offer each other. Sri Lanka’s cascades demonstrate how ecological buffers, small-scale retention and community cooperation create climate resilience. Hungary’s experience with transboundary water diplomacy, large-infrastructure operation, flood-risk management and digital basin-control systems – such as those on the Tisza – provides complementary insights.
Thanks to the collaboration between NKE’s Ludovika Fellowship Program and the Hungarian water-management community, this exchange opened genuine two-way learning – a vica vera in the best sense. As climate extremes intensify, combining traditional ecological wisdom with state-of-the-art engineering may be the most effective path forward for both countries.
Text and translation: dr. László Balatonyi, International Department, General Directorate of Water Management of Hungary