Increased stormwater runoff as a consequence of climate change-induced heavy rainfall events pose critical threats to urban aquatic biodiversity. Specifically, combined drainage systems which transport wastewater, stormwater and urban water together can flood after heavy rainfall, causing a discharge of wastewater and contaminated runoff directly into rivers, streams or other nearby water bodies.
The NICHES project (‘Nature’s integration into cities’ hydrologies, ecologies, and societies’) recognises this threat and aims to showcase the potential of nature-based solutions (NBS) to mitigate the negative impacts of such combined sewage overflow events on society and the environment. NBS such as riverbank restoration, sustainable urban drainage systems, and the regeneration of urban green belts can act as an alternative to the cost-intensive renewal of wastewater systems and as a supplementary element to existing stormwater management systems.
Despite this potential, the use of NBS for urban water management remains limited. This is in part due to lacking evidence, approaches and targeted guidance available to decision-makers, practitioners and other relevant groups. NICHES aims to bridge this gap by defining a holistic framework for understanding the social, ecological and technical aspects of applying restorative NBS for urban runoff mitigation and the resultant benefits for aquatic systems. Using its five global cities as co-design arenas, the project will also support the development of recommendations for integrating NBS in urban policies.
The project kickstarted with a consortium meeting on 21-22 April 2022 in Berlin, Germany. Hosted by the Ecologic Institute, the kick-off meeting welcomed 11 experts from the seven partner institutions. These partners also represent the cities that the project’s research will focus on, including Barcelona (Spain), Rotterdam (Netherlands), Boston (USA), Berlin (Germany) and Sheffield (UK).
“Current combined sewage systems cannot cope with the increasing impacts of climate change,” comments Project Coordinator McKenna Davis from the Ecologic Institute. “Resultant pollution from sewage overflow events introduce harmful bacteria, pathogens, and solid waste into water bodies and threaten aquatic biodiversity. A shift towards the use of nature-based solutions to complement traditional systems is needed.”
Through the research and analysis of NICHES findings in these cities, the project will advance scientific knowledge about restorative NBS and demonstrate its mitigation potential for tackling combined sewage overflow. Improvements in terms of citizen engagement, spatial planning, maintenance, and the integration of water governance structures will support ecological improvements and generate wider societal benefits.
