Overview
- The new stress-test maps indicate that low-lying polders typically fill to around 60 centimeters, with some locations exceeding 1 meter, and water often remains for one to three weeks after 150–300 millimeters of rain in 48 hours.
- Urban areas face prolonged disruption with risks to accessibility and building integrity, particularly where critical infrastructure such as power cabinets, telecom links, and main roads are located.
- Model outputs exclude sewer systems and lack street-level detail, which officials say likely understates vulnerability in cities where drainage failures can worsen flooding.
- The ARK-NZK results form part of a 13-region national program led by provinces, water boards, and Rijkswaterstaat, with Sweco modeling scenarios comparable to the 2021 Limburg deluge.
- Provinces will now work with safety regions and water authorities to map impacts on vital and vulnerable functions, including hospitals and dikes, with Utrecht planning consultations from late 2025 and results feeding into the National Approach to Water Nuisance in 2026.