Nordic Cities Turn to AI to Outsmart the Rain

Opti-SITE cuts site selection from weeks to days as utilities in Denmark and Sweden test AI-led flood planning

16 Jan 2025

A new artificial intelligence tool is beginning to change how Nordic cities plan defences against flooding, as climate change increases the pressure on ageing urban drainage systems.

Opti-SITE, developed by Sweden Water Research alongside consultancy DHI, Aalborg University and utilities including Copenhagen’s HOFOR and southern Sweden’s NSVA, is designed to speed up decisions on where to place green stormwater infrastructure.

The platform combines rainfall radar data, detailed terrain models and automated analysis to identify suitable locations for measures such as rain gardens, bioswales and retention ponds. These systems can reduce flood risk by absorbing and slowing runoff during heavy rain, but identifying the best sites has traditionally required weeks of manual analysis.

Pilot projects in Copenhagen and the Swedish city of Landskrona suggest the process can now be completed in days. Project partners say this can reduce planning time by around 40 per cent, allowing utilities to move more quickly from analysis to construction.

“This is a game-changer,” said a HOFOR representative. “We’re accelerating projects and achieving better outcomes for both residents and the environment.”

The developers say Opti-SITE is intended to work alongside existing planning and geographic information systems, limiting the need for major changes to municipal workflows. That approach could make it easier for cities to adopt the technology as they face tighter budgets and stricter European Union requirements on water management and flood risk.

Interest in the tool reflects a broader shift towards data-driven infrastructure planning across Europe, as cities seek ways to respond more quickly to extreme weather without relying solely on costly underground pipe upgrades.

However, researchers involved in the project caution that software alone cannot solve urban flooding. Local knowledge, public engagement and political backing remain critical, particularly when green infrastructure affects land use and neighbourhood design.

Opti-SITE is still at an early stage, but its backers say further trials are planned. For Nordic utilities under growing climate pressure, the focus is less on novelty than on whether the technology can deliver faster, more consistent decisions at scale.