Espoo seeks new solutions for water management and nutrient pollution in the drainage area of Lake Pitkäjärvi

20.1.2023 12.59

Water management in the drainage area of Lake Pitkäjärvi has become more challenging in recent years. Due to nutrient pollution coming from many sources, the lake has become eutrophic and increasing amounts of blue-green algae have been observed in the lake.

Heavy rains have repeatedly caused flooding along streams flowing into Lake Pitkäjärvi. One of the affected roads is Vihdintie. The aim is to improve the ecological status of Lake Pitkäjärvi from poor to good by 2027.

The drainage area of Lake Pitkäjärvi (69 km2) stretches from Träskända in Espoo to Keimola in Vantaa. The large drainage area includes both agriculture and forestry, nature reserves, residential and industrial buildings and major roads, such as Ring III and Vihdintie.

The cities of Vantaa and Espoo and the Uusimaa ELY Centre will carry out a joint pilot project to explore solutions for improving the ecological status of the drainage area of Lake Pitkäjärvi. The project team will prepare a water management plan for the entire drainage area, which will provide guidelines for water management in agricultural and forestry areas and built environments. The project team will also develop cooperation between cities and agricultural and forestry operators in issues concerning drainage area water management. The project is funded by the water protection programme of the Ministry of the Environment.

The two-year project (2022–2024) includes preparing a general plan for water management in the drainage area of Lake Pitkäjärvi, based on which two nature-based water management solutions will be implemented, one in Espoo and one in Vantaa. Finally, the project team will produce a report on what has been learned during the project, the cooperation models, and whether the project can be replicated in other similar sites nationwide.

During the project, stakeholder events and two resident events will be held. The residents’ events will take place in spring 2023 and in the final phase of the project in 2024. Information on the events will be provided on the cities’ information channels and the project’s website:

For more information, you can contact the representatives of the project team:

Iiro Lehtinen, Planning Engineer,
Saara Olsen, Limnologist,
Kari Rantakokko, Senior Specialist, Water Resources Management,


Espoon keskusKalajärviLeppävaara