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Urban areas are enlarging and impact surrounding natural ecosystems.

Domestic and industrial wastewater get into rivers, and in addition runoff from impervious urban surfaces alters local hydrology and can contribute a diverse array of pollutants.

The effects of these pollutants on receiving river ecosystems are poorly known, and it is likely that might increase as a consequence of ongoing climate change. In particular, extreme climatic events, such as unusually long dry periods followed by large rainfalls, may accentuate the massive transport of urban runoff from urban settings to rivers or lakes. 


CityPoll addresses this information gap by means of multidisciplinary research on hydrology, environmental chemistry, ecotoxicology, and ecology. CityPoll combines 3 subprojects: subproject 1 (ICRA) on hydrology, chemistry, and their effects on biofilms; subproject 2 (UB) on ecotoxicological effects on invertebrates and on the emission of greenhouse gases; subproject 3 (EHU) on ecosystem functioning and on the mitigating effects by buffer areas. 

Using the most advanced analytical tools to monitor urban runoff, CityPoll will prioritize the contaminants according to their occurrence and toxicity, and associate specific pollutants with specific types of urban areas. Particular attention will be given to suspended materials, nutrients, regulated and emerging microcontaminants, and microplastics. Using micro- and mesocosm studies, CityPoll will study the ecotoxicological effects of urban runoffs on a range of organisms, from microbes to invertebrates. Using collected runoffs from urban settings, and artificial mixtures with the most common pollutants in urban areas, experiments with artificial channels and other mesocosms will allow detecting the main effects on river food chains. Under these settings, CityPoll will also analyse the ecological effects of urban runoff on a range of ecosystem processes, from nutrient dynamics to greenhouse gas emissions.

Providing a translation to real urban environments, CityPoll will create a hydrological model for the case studies selected in the project, integrating the sewer and the receiving river systems, to jointly analyse and monitor the path of water and contaminants between urban areas and receiving rivers during rainfall events. CityPoll will combine automatic sampling of natural rain events with the follow-up of experimental rainfall and with. 

CityPoll will transfer and disseminate the multi-layered evidence collected to a wide range of targets, from urban and water managers to scientists and to the public. CityPoll will then produce guidelines, protocols, scientific papers, press releases and a video documentary. These guidelines and protocols will be of use beyond the specific case studies of CityPoll. The project will also contribute to the development of new digital solutions for runoff monitoring, strengthening the European industry once new procedures and strategies become transposed into worldwide standards. 


Total cost:

514,528 €

Coordinated by:

Catalan Institute for Water Research (ICRA-CERCA)

Participated by:

Universitat de Barcelona (UB) and Universidad del País Vasco (UPV-EHU)

Funded by:

Ministerio de Ciencia e Innovación, Proyectos de transición ecológica y transición digital 2021, TED2021-129966B-C31



Will contribute to the consortium through its expertise on analytical chemistry, connaissance of the urban water cycle, and response of biofilms. As such, the analysis of multiple families of contaminants (organics, microplastics) and their prioritization; the digitalization and hydraulic modelling; and the ecotoxicological and ecological responses of the biofilm. In addition, ICRA will perform as coordinator of the three teams.

ICRA-CERCA. Catalan Institute for Water 


Will contribute to the consortium through: i) the analysis of the inorganic contaminants to characterize urban runoff; ii) the evaluation of the effects of runoff pollution on invertebrate diversity in the receiving rivers; iii) the evaluation of the potential toxicity of runoff pollution on invertebrates; iv) the  quantification of gas emission and of the dissolved organic matter changes.

University of Barcelona

Will contribute to the consortium through i) the characterization of runoff characteristics under contrasting urban contexts, by means of experimental manipulation in several urban areas; ii) the assessment of the effects of pollution on ecosystem functions in the receiving streams; iii) the quantification of the mitigating effects of buffer zones on the ecological responses ; iv) different aspects of communication to the general public and managers.

University of the Basque Country

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