Realisation of flood protection measures for the city of Prague

Following the devastating 2002 Vltava River flood, which caused an estimated CZK 24 billion (about EUR 1 billion) in damage, Prague accelerated construction of a city-wide flood-control system combining grey infrastructure (fixed and mobile barriers, safety valves) with green measures such as floodplain and watercourse restoration for flash floods.

The programme aims to protect the city, including its historic centre, against a 1-in-500-year flood event (plus a 30 cm safety margin), compared with the 1-in-100-year standard of the previous defences, in line with the Prague Climate Change Adaptation Strategy (2020).

The flood-control system was built in eight phases addressing different sections of the Vltava River, comprising about 19.3 km of fixed and mobile barriers (of which 6.9 km are mobile), plus pumping systems and canalisation safety valves. Mobile barriers are stored centrally in Dubeč, with a dedicated training area and annual installation exercises. A 2022 building permit unified protection across the city to the 1-in-500-year standard, extending the level previously applied only in the Old Town.

The estimated total cost of the flood-control system is about EUR 145.9 million (2013 prices), including construction (EUR 144.4 million), per-event installation costs (EUR 0.65 million) and annual maintenance/storage (EUR 0.89 million). A cost-benefit analysis estimated avoided damage costs of between EUR 168 million (for a 1-in-20-year event) and EUR 2,003 million (for a 1-in-500-year event), concluding that benefits exceed costs for any event of 1-in-50-year magnitude or greater. Before construction, 57.5 km² of Prague (11.6% of the city) was flood-exposed; after completion, 52.5 km² of that area is protected. During the 2013 flood, the system held with only minor localised flooding.

Implementation faced friction between flood-protection engineering and cultural-heritage preservation requirements in the historic centre, resolved by substituting stone elements for stainless steel and mobile barriers for permanent walls in sensitive areas, and by offering compensation or land exchanges to affected property owners. The 2013 flood exposed a remaining weak point at the Rokytka pumping station, whose capacity is being doubled under a permit issued but not yet built as of 2023.