Stormwater network analysis in Tampere, Finland

AFRY was assigned to implement comprehensive stormwater network analysis in Tampere, Finland already in 2014. The model has proved to be useful several times afterwards.

In 2014, an operational study of the stormwater system of Tampere city centre was carried out. The assignment comprised calibration measurements, preparation of flood risk maps, definition of flood routes, estimating of the impacts of alterations of land use on the stormwater flows, and specified the measures required to prevent flooding by stormwater detention or alternatively by increasing the capacity of the network. Besides measurements, potential areas dedicated for stormwater retention structures were presented.

The area in question is very densely built. Additionally, the study took into consideration areas with combined sewer systems. Size of the design area was about 464 hectares and it contained about 46 km of modelled network.

The model has been further utilized in modelling tasks later. In 2017-2018, a modelling of an update of stormwater network model in the city centre, Rongankatu street, was carried out. The city centre’s stormwater network model was updated regarding the new flood pipeline and stormwater tank, and the retention volumes required to prevent the flooding of the Rongankatu street in various heavy rain situations were determined.

In 2018-2019, a stormwater study of the Amuri district to support land-use planning was carried out. The project produced initial data and a framework for the further development of the area also in terms of stormwater management. The stormwater management in the Amuri district was studied as a whole and the main targets for stormwater management were specified with the help of modelling. In addition, preliminary dimensioning of the detention structure was prepared.