RAINMAN project

Towards higher adaptive capacity in urban water management

Climate change increases precipitation and urbanisation leads to soil sealing. This can increase sewer overloads and urban flooding. Untreated floodwater can contaminate surface and groundwater.  The RAINMAN project reduces sewage system overloads and urban flooding caused by stormwater and preserves water resources.  The project develops and implements solutions with the aim of ensuring the good state of surface water and groundwater, despite the effects of climate change.

In the project, HSY produces data on the stormwater information management model, the importance of green structures in stormwater management in various urban environments, and the use of the green factor. In addition, HSY participates in information exchange and training events with the project partners. 

The three-year project is coordinated by the Geological Survey of Finland (GTK). In addition to HSY, partners include the cities of Lahti and Mikkeli as well as three research institutes operating in St. Petersburg. The project was co-funded by the European Union.



Press release 4.3.2021

Nature-based solutions support sustainable stormwater management

Global climate change is expected to increase precipitation and intensify cloudbursts in Southern Finland. Simultaneously, cities’ growth and densification lead to an increase in impermeable surfaces. Management of stormwater will consequently be more challenging in the future. Helsinki Region Environmental Services Authority (HSY) has published a report presenting nature-based solutions for stormwater management that serve as practical examples for urban areas, focusing on the Helsinki Metropolitan Area.

Vegetation plays an important role in nature-based solutions.

- Most of the current stormwater infrastructure has been designed for past climate conditions and it is therefore not fitted to manage increasing amounts of water. Vegetation and other natural elements that convey or treat stormwater play an important role in nature-based solutions, says HSY’s Climate Specialist Maaria Parry.

Nature-based stormwater management approaches support the natural cycle of water. HSY has published a report in which selected in-situ solutions are identified and studied. The report gives insight on what types of nature-based solutions can be utilised and what factors are facilitating and, on the other hand, hindering the planning and implementation of these solutions.

Stormwater management solutions can enhance recreational values

- Nature-based solutions often provide multiple benefits. Along with stormwater management, they can preserve biodiversity and enhance recreational values. It is important to plan these sites carefully and openly. Also, it should be noted that nature-based solutions require monitoring and maintenance, Parry reminds.

One of the sites featured in the report is the Thurmaninpuisto park in the city of Kauniainen. Through the park flows the Skvatterbäck creek, which collects stormwater from the city centre. The original creek was modified to detain water and to make it an attractive part of the park. The plants on the edges of the creek were selected so that they need less maintenance and withstand changing conditions.

The report called “Nature-based solutions for stormwater management in the Helsinki Metropolitan Area, Finland – Prerequisites and good practices” supports the adoption of nature-based stormwater management solutions.

The report work was carried out as part of the project titled RAINMAN – Towards higher adaptive capacity in urban water management. The project aimed to enhance the capacity of cities and municipalities to cope with climate change impacts such as increasing stormwater volumes, especially within urbanised areas.