05 Suolijärvi nature trail information board

From a forest lake to an urban lake

The shoreline of Lake Suolijärvi is currently uninhabited, but the old stone foundations in the area suggest that this has not always been so...

Maps reveal these foundations as cottages built in the 1950s, having disappeared since the 21st century. The construction of Hervanta, which began in the 1970s, has significantly increased the human impact on Lake Suolijärvi. Can you think of any ways in which this change may have been reflected on the lake?

How does urbanisation affect Lake Suolijärvi?

The condition of the lake is affected by land use in the surrounding area. The most significant nutrient and chemical load to Lake Suolijärvi comes from the Hervanta residential area in the form of stormwater run-off. Stormwater is water that is not absorbed into the soil and is particularly high in volume in urban areas due to asphalt and higher rainfall volume. 

Stormwater contains pollutants such as heavy metals and pesticides from industry, construction, traffic and other parts of modern life. As pollutants accumulate on the lakebed, they endanger the well-being of benthic organisms and, in the long term, potentially the whole biota.

Protecting lakes in urban areas

As we grow more knowledgeable, it is becoming clear that there are many simple ways to improve the state of lakes. Urban green spaces and wetlands are important filters of water, reducing the amount of pollutants entering water bodies. The picture shows a naturalised stormwater pond, which allows some pollutants to be trapped in the ground instead of being discharged into water bodies.

What can we do to improve the condition of lakes?

In cities, you can reduce water pollution by cleaning up dog waste and cigarette butts, by reducing the use of fertilisers, pesticides, and cars, or by preserving vegetation.