According to Climate Strategy for Oslo towards 2030, increased periods of heavy rainfall combined with urban development and paved areas will result in increased stormwater and urban flooding in Oslo. Much of the stormwater ends up together with sewage in pipes underground to wastewater treatment plants. During periods of heavy rainfall, these pipes overflow directly into rivers and Oslofjord without any treatment, discharging harmful environmental pollutants.
As a part of Oslo’s Climate Strategy, the City of Oslo identifies 16 areas of priority, among them:
“Oslo will preserve and restore its watercourses, fjord, parks and outdoor recreation areas. Oslo will develop the city from the city centre outwards and densify around public transport hubs.”
With higher temperatures, more frequent and intense precipitation, increasing stormwater and urban floods, and a growing population, it will be important to utilize the already limited space with new and innovative technologies. Nature-based solutions for water treatment (NBSWT) such as rain gardens will be an important instrument in mitigating climate change and implementing the Climate Strategy for Oslo towards 2030. It will also be important to evaluate the performance of such systems in a Scandinavian climate with cold temperature, snow during winter, and snow melt in the spring. Strengthening the status of urban habitats and data gathered from monitoring will help create tools and guidance to adopt and maintain NBSWT in urban settings and offer policy recommendations to safely reuse water in urban areas. In this way, NBSWT will be important to build cities in a climate-friendly way for a better future.