RAINMAN aims at answering the challenges climate change and urban development are posing to freshwater reservoirs. It focuses on reducing the overload of existing sewage systems, urban flooding, as well as groundwater vulnerability.
The discharge of nutrients and hazardous substances from urban areas into the Gulf of Finland and its water bodies continues to be high. Climate change causes increased precipitation. This can lead to overload of existing sewage systems, urban flooding, as well as an increase in surface runoff and subsurface discharge. The increase in sealed surfaces and artificial surfaces (e.g. roofs, streets, parking lots) also affects surface runoff and urban flood patterns.
Densely built-up urban areas are potential sources of nutrients and hazardous substances due to overflow of combined sewage systems, washout of potential contaminated sites or runoff of road maintenance chemicals. Because cities and municipalities are often in close vicinity to freshwater resources, these impacts are an actual challenge for urban development, especially when near-by freshwater resources are used for drinking water supply. Cities and municipalities continue to expand and densify in these sensitive areas. Thus, feasible short- and long-term solutions are needed to manage increasing amounts of storm water in a sustainable way.
The project studies innovative solutions to maintain and preserve the freshwater reservoirs and to enhance a safe living environment. The main objectives of the project are to develop feasible and innovative solutions to ensure a good state of freshwater resources within a changing climate and intensified land use, and to integrate selected solutions into city development guidelines and plans.
The project focuses on the needs of Mikkeli, Lahti, and the Helsinki Metropolitan Area in Finland, and St. Petersburg in Russia.In St. Petersburg and in the Helsinki Metropolitan Region the aim is to reduce the risk of sewage system overflows and consequently the outflow of untreated wastewater (often a mix of wastewater and rainwater) into the Baltic Sea. As such, the appropriate dimensioning of the sewage system, the development of sustainable urban drainage solutions and the correct assignment of responsibilities to the city, the water works and to the citizens themselves is important. The RAINMAN project provides the necessary knowledge to achieve this, including information about potential future climate change and soil sealing.
In Mikkeli and Lahti, the key challenges are the infiltration of nutrients and hazardous substances into streams, lakes, and groundwater. Thus, there is a demand here to identify the run-off routes of rainwater, groundwater flow and potential sources of contamination. This knowledge provides valuable input in respect of the update of groundwater protection plans. It will also help to protect the drinking water of Mikkeli and Lahti now and in the future.
Duration: 01.01.2019 - 31.12.2021
Total budget: 940 202 €
CBC funding: 751 161 €