Author(s): Conrad Schiffmann; Jose Ricardo Bonilla Brenes; Jochen Hack

Linked Author(s): Conrad Schiffmann, Jose Ricardo Bonilla Brenes, Jochen Hack

Keywords: Green infrastructure, implementation, barriers, transdisciplinary, Costa Rica

Abstract: The Quebrada Seca is an urban river within the Great Metropolitan Area of Costa Rica. The lack of planning of nearby residential developments and treatment systems increased runoff volume causing severe flooding and riverbank instability. The issue rose to such relevance that the Constitutional Chamber of the Supreme Court of Costa Rica, through vote 4050, decreed that any riparian municipalities may initiate actions to favor the recovery of the basin. A solution is to reestablish the natural hydrological cycle by replacing waterproof coverage with natural elements in the public space through green infrastructure implementation. As planned networks of natural and semi-natural areas, green infrastructure enables interception, infiltration, puddling, and evapotranspiration processes, which are essential to decrease surface runoff volume and peak flows. In Costa Rica, however, although sustainable development and nature-based solutions were promoted in recent years, implementation of such solutions in urban areas is still lacking. Past research emphasized the lack of knowledge of decision-makers as one of the main challenges in implementing green infrastructure. A decision favoring sustainable solutions is often circumvented because concrete benefits and performance are not sufficiently clarified. In addition, there are also doubts about the legal framework and possibilities of implementation. Especially when it comes to changing the use and design of public space, e.g., street layouts and multifunctional designs, there are doubts about the responsibility and intervention possibilities. This study aims to develop a combined legal-hydrological evaluation method for green infrastructure in urban Costa Rica. First, the potential of four types of retrofitted green infrastructure elements to reduce stormwater runoff was calculated by hydrological modeling at a neighborhood scale taking into account site-specific constraints. Second, the legal complexity of the intervention in the public space resulting from the construction of the four elements was investigated through qualitative expert interviews in the form of focal groups. Finally, by linking the results of the two previous steps, this study presents an interdisciplinary evaluation of the impact and the probability of prompt realization of the four green infrastructure types. By ranking the four proposed solutions, an explicit recommendation for action was made. The combined results of this study provide a more versatile vision of evaluation possibilities for the feasibility of green infrastructure in public spaces in retrofitting contexts. By that, the results provide information about which technical and legal information is relevant for implementing urban green infrastructure and how much importance is attached to this body of knowledge in the decision-making process.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022SS2039

Year: 2022