This deliverable 3.1 (D3.1) is the first one of the Work Package 3 (WP3) in the D4RUNOFF project. WP3 is divided in four tasks of six months each, with a total of three deliverables. In this one, the work done during the first year of the project is summarised in a public document open to comments and suggestions: the urban drainage library and the parametric design of the Nature-Based Solutions (NBS) included in this library. The next two deliverables (D3.2 and D3.3) will complete the WP3 adding the Multi-Criteria Decision Analysis (MCDA) and the Geographical Information Systems (GIS) with the final aim of selecting the best place for the NBS needed to improve the existing urban drainage conditions.
The principal objective of the D3.1 is to propose a library of urban drainage solutions and a simplified parametric design methodology of the NBS. Firstly, the D4RUNOFF researchers have reviewed the main references, highlighting the NBS classification made by the European project Green-Up, to propose a simplified list of techniques that includes a total of 13 NBS in the context of the urban drainage. Each one of the techniques included in the library counts with a complete file that includes information related with different aspects and criteria to be considered during the decision-making process. Afterwards, the design methodology of each one of the NBS was studied, identifying the main parameters like occupation area or water depth. With this knowledge, an Excel spreadsheet has been prepared to help with the initial design. This tool is openly available as annex and a specific chapter describes how to use it. Moreover, from the parametric calculations, a methodology to develop NBS drainage elements for Building Information Modelling (BIM) is proposed, giving the needed instructions to work with the NBS design Excel spreadsheet. This methodology has been complemented by a detailed state of the art regarding the existing scientific publications dealing with the depuration capacity of some Contaminants of Emerging Concern (CECs) by the NBS.
As main final remarks, it is important to highlight the maturity of the main typologies of NBS, mainly related with infiltration (e.g., bioretention areas), and the probed depuration capacity of the NBS and their positive impact the drainage systems and the whole cities, with multiple advantages related with sustainability and resilience. With all, there is a deficit of knowledge in how some techniques deal with CECs, which confirms the need of new screening methods and sensors to make it possible to improve the monitorization of NBS soon.