Modernised solution boosts flood resilience and promotes sustainable urban development 

Żary, a picturesque town in western Poland, is known for its historical charm and tranquil environment. However, like many growing urban areas, it is facing significant challenges in managing its stormwater drainage system. As rainfall patterns become more intense and urbanisation increases, the municipality of Żary is proactively upgrading its infrastructure to improve water management and address the challenges of frequent flooding. With a modernized stormwater management solution developed by DHI, Żary is now better positioned to mitigate flood risks, enhance urban resilience and ensure sustainable development in this vibrant community.

Challenge

Situated on flat terrain, Żary is prone to frequent flooding. To address this, the municipality is actively upgrading its infrastructure to better adapt to modern climate patterns and support ongoing urban development. Previous patchwork repairs and minor upgrades did not fully resolve the persistent flooding issues. Consequently, residents faced property damage, traffic disruptions and environmental challenges, with flooded streets and overwhelmed sewers becoming frequent during heavy rains. Recognising these impacts on quality of life, the municipality of Żary is committed to implementing comprehensive solutions to improve flood management and enhance overall resilience.

Solution

As part of the ‘Żary - A Place to Live’ initiative, DHI conducted an extensive measurement campaign conducted over two months, involving six stormwater channel stations and two rain gauge stations. This data collection laid the groundwork for accurate modelling and recommendations for system optimisation. 

After collecting the data, we developed and calibrated hydrodynamic models for both stormwater and sanitary sewer systems. Detailed analysis using these models pinpointed critical areas and bottlenecks, leading to targeted recommendations for infrastructure upgrades and the addition of retention tanks. 

The project also included implementing an advanced software solution for real-time data visualisation and management, creating web applications for proactive stormwater control and conducting a field inventory of sewer infrastructure.

What made DHI’s solution unique? 

• Hybrid modelling: The integration of 1D+2D modelling provided a comprehensive view of the drainage system’s performance under various conditions, combining sewer network modelling with natural watercourse and terrain surface simulations
• Predictive capabilities: The system could forecast network behaviour up to six hours ahead, providing early warnings of potential flooding. This proactive approach allowed the municipality to take preventive measures before issues escalated.
• Green infrastructure: Adding green infrastructure elements like rain gardens, green roofs and permeable surfaces not only improved stormwater management but also contributed to urban aesthetics and environmental quality

Compared to traditional methods, DHI’s approach offered superior predictive and integrative capabilities, utilising advanced technologies like MIKE software, online data platforms and AI integration.

Results

The solution has significantly improved Żary’s sewage system, greatly reducing flood risks and enhancing surface water quality. The municipality can now predict and manage potential flooding events more effectively, minimising their impact on residents. By integrating modern monitoring systems for continuous data visualisation and analysis, Żary is now well-equipped for proactive water resource management, benefiting the entire community.