Resilient Blue-Green Infrastructure for Urban Water Management: Pilot Rain Gardens and Hybrid Retention Systems in Krakow

The project addresses the urgent need for adaptive and sustainable water management in urban areas under climate change. By piloting two innovative solutions, Krakow will develop new standards for resilient ecological and social infrastructure:

1. Model rain garden with sensors and water balance analysis.

This pilot will establish a prototype rain garden in Krakow as a demonstration of innovative blue-green infrastructure. Various substrates will be tested to evaluate their retention and purification capacities, while sensors will monitor water quality (before and after filtration) and the complete water balance (retention, absorption, evaporation, and drainage). The effectiveness of the garden in mitigating climate change will be assessed through its contribution to rainwater retention, microclimate cooling, and surface water quality improvement. The pilot will also explore the garden’s role as a social space for recreation and environmental education. The results will inform guidelines for the city on the design, location, and maintenance of rain gardens, enabling their inclusion in local plans and public procurement.

2. Hybrid system for retention, infiltration, and pre-treatment in the Bieżanowski Ditch

This pilot will introduce an integrated system combining retention reservoirs, infiltration zones, biological and plant-based filters, and pre-treatment devices. Implemented in the Bieżanowski Ditch – an importnat rainwater collector – the system will reduce flood risk, relieve storm sewer overload, and improve water quality before discharge into the Vistula River. Monitoring and modelling tools will be installed to evaluate system performance, with particular attention to the potential reuse of treated stormwater in municipal services (e.g., irrigation of green areas). This pilot will demonstrate how technical and ecological infrastructures can be integrated at the catchment scale, providing systemic, replicable solutions for circular urban water economies.

Innovation and Horizon Europe relevance:

The project directly supports DUT priorities by advancing Nature-Based Solutions, digital monitoring, circular urban economy principles, and participatory governance. Both pilots will generate evidence-based design and maintenance models, accompanied by policy recommendations for Krakow, supporting replication in other European cities.

Expected results:

• prototypes of rain gardens and hybrid retention systems with documented performance data,

• transferable design and maintenance models for sustainable stormwater management,

• reduced flood risk, improved water quality, and enhanced urban climate resilience,

• policy recommendations for integrating NBS and hybrid systems into urban planning and public procurement,

• strengthened cooperation between local authorities, research organisations, enterprises, and residents in co-creating sustainable urban infrastructure.

Both solutions will serve as prototypes for scalable and replicable approaches to stormwater management, combining Nature-Based Solutions (NBS), digital tools, and participatory governance.