How to use nature-based solutions in urban planning systems of Europe?

International audienceIn developed countries, the level of urbanization is still rising and expected to reach 83% in 2030 [United Nations, 2012]. As a result of rapid growing of urban areas and population, the urban planners several challenges. For example, risks of flooding due to overload of the drainage system, and pollution due to combined sewer overflows and diffuse pollution, consequently increase significantly. Questions about biodiversity promotion and urban heat islands are also emerging as major issues in the construction of sustainable cities [Berretta et al; 2014].European Commission, (2015) highlighted nature-based solutions in order to address the mentioned urban problems related to climatic, demographic and technological changes. The aim is to bring new solutions into urban planning and thus, to address those challenges and to improve the well-being sensation, quality of life of city dwellers.Nature-based solutions (NBS) are one of the newest concepts for tackling urban challenges. The concept of NBS was meant to reform the methodology of urban planning in EU countries and deliver multiple environmental, social and economic benefits through introducing and implementing a new toolkit based on natural resources. In the Horizon 2020 project, Nature4Cities besides multi-thematic and multi-scalar evaluation of nature-based solutions and their effectiveness in addressing different urban challenges we aim to deliver a platform used by urban planners. As an important step of producing the platform in this paper we analyse the possibilities of implementing nature-based solutions in the different planning systems of Europe. First, we give a short overview on similarities and differences between planning systems, and the different kind of plans (master plans, action plans, authorization plans, … etc.) Secondly, we describe Nature4Cities concept on NBS-typology, and thirdly we analyse the possibilities of inserting the particular nature-based solutions into the different kind of plans in different scales. As a result, we wish to establish a baseline of "business as usual" urban operations and how the mainstream "grey solutions" could be replaced by NBS. We also put emphasis on the social aspects of urban planning and that of NBS’: what are the alternative governance and participatory processes that enhance the implementation of NBS