Background The stream of Usserød in the northern part of Sealand, Denmark is receiving increasing amounts of water from rainwater and sewage systems as a consequence of climate change and the gradual expansion of urban areas in the municipalities of Rudersdal, Hørsholm and Fredensborg. The stream is 8 km long and flows from the Lake of Sjælsø in the west to the Strait of Øresund in the east. In Denmark over the four summers, 2007-2010, more high-intensity rain storms were recorded than in the past. Very strong individual rain events have occurred and so have periods of heavy rain over a few days – the ‘renewable rain’ phenomenon. Both cases can leading to flooding, as was the case in Fredensborg Kommune in the summer of 2010, when more than 70 houses were directly affected. Run-off from precipitation is generally expected to become more extreme in Denmark in the coming years, increasing the climate change challenge. It is therefore necessary to assess the entire water cycle to identify solutions for the years to come. Additionally, alternative thinking is necessary to create solutions and methods that embrace and include all three municipalities – as water does not respect municipality borders. Objectives The project’s key objective is climate change adaptation. The specific aims of the project are: To reduce risks of critical floods along the stream of Usserød; To reduce the risk of damage and associated economic, societal and human costs if floods are not avoided; To increase awareness of the stream and its resources among citizens, politicians and civil servants; and To create a basis for all parties to implement proactive, holistic actions around development, operation and maintenance of the stream of Usserød, making it a unifying positive element for the municipalities hosting the stream. Expected results: Enhanced and more controlled monitoring of the stream of Usserød; Improved emergency preparedness before, during and after critical events; Creation of a Joint Emergency Plan; Fewer critical events around the stream of Usserød during heavy rain and torrential rain; Proven lower societal and human costs further to critical events; and Implementation of a joint climate change adaptation toolkit. This will consist of a joint hydraulic model, a hydraulic documentation tool, new water meters and a joint flood risk map.