Storm water management is a subject now high on the agendas of many cities in Northern Europe. Two major phenomena drive the need for improvement in storm water management and the search for alternative approaches; the expectation of more heavy downpours and an ever-increasing amount of sealed surface. Combined, these two factors can cause sewage system overloads and urban flooding. Nutrients and hazardous substances can also contaminate fresh water resources if storm water is not treated properly.
The project “Towards higher adaptive capacity in urban water management” (RAINMAN) under the lead of the Geological Survey of Finland (GTK) has embarked on the process of developing solutions that can be integrated into city development guidelines and plans for the maintenance of fresh water resources in a good state, despite the changing climate. The project focuses on the needs of Mikkeli, Lahti, and the Helsinki Metropolitan Area in Finland, and St. Petersburg in Russia.
These areas obviously present a diverse range of challenges. 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.
Given the opportunities for study and comparison that the combination of these cases presents the project can provide a set of solutions that will be suitable for a range of different urban forms covering historical urban areas, densely built areas, areas under development, and as yet unbuilt areas.
The project consortium includes municipalities and research organisations from St. Petersburg and from the regions of South-Savo, Päijät-Häme and Uusimaa in Finland. The Project Partners – in addition to GTK– are State Unitary Enterprise “Vodokanal of St. Petersburg”, the Russian State Hydrological Institute, the Voeikov Main Geophysical Observatory, the Helsinki Region Environmental Services Authority, the City of Lahti, and the City of Mikkeli.
Each of the partners has a crucial role in the project. The research organisations provide the necessary climate change data and engage in the modelling of water networks and the flow of surface water and ground water. Together with the municipalities and water utilities as project partners they can reduce the vulnerabilities of the urban water management systems.
The RAINMAN partners gathered together for the first time on January 29-30 at GTK and launched their work to prevent urban flooding and to preserve fresh water resources.
RAINMAN is part of the South-East Finland – Russia CBC 2014-2020 programme and is funded by the European Union, the Russian Federation and the Republic of Finland.
Text: Johannes Klein
Johannes Klein (D.Sc.) works at the Environmental Geology unit. His fields of expertise are climate change adaptation, risk assessment and urban planning.