Resumen
Urban drainage systems play an important role in the complex ecosystem of cities and are often subject to challenges that hinder their functioning. Although identifying these challenges is essential for developing policies and actions to improve drainage systems, there is a lack of studies addressing these challenges. This work has two objectives to contribute to filling this gap: (1) to research the main challenges that make it difficult to improve urban drainage systems; and (2) to prioritize them. We conducted extensive and detailed bibliographic research in which 15 challenges were identified, and a survey with 30 Brazilian professionals with experience in the concerned field. The results showed that 15 challenges identified in the literature were considered important by the survey respondents. It also showed that the most important challenges concern the inadequate functioning of drainage infrastructure, dynamics of city expansion, system maintenance, vulnerability of urban areas, public policies, and investments.