Potential for Applying Nature-Based Solutions to Urban Waterways: The Case Study of Medveščak and Črnomerec Streams in the City of Zagreb, Croatia

This paper explores the application of sustainable nature-based solutions as an alternative to conventional grey infrastructure for managing waterways in the city of Zagreb, Croatia. The city has an extensive network of canalised urban streams, some of which are closed, flowing into the City’s sewage system and into the Sava River. However, some of these open watercourses are not fully utilised due to the inadequate management of blue infrastructure. Climate change adds pressure to conventional approaches, creating an urgent need for flexible solutions. This paper analyses different locations to assess the possibilities for safeguarding, revitalising, and developing blue and green infrastructure. Based on a thorough analysis, the synthesis of previous urban practice examples for the city area, and the research of the experiences and theoretical knowledge on the issue, this paper proposes sustainable solutions for Medveščak and Črnomerec streams in Zagreb, such as water storage and purification. The proposed solutions hold significant potential to address issues related to water supply, protection, and nature preservation in a more flexible and adaptable manner. This paper proposes solutions that provide a practical framework for the future implementation of nature-based solutions and development in other urban regions.