In 1939, the decision was made to build a new hydropower plant in Oulu. However, there was a major shortage of materials and workers, first due to the Winter War and then the Continuation War, and this affected the execution, schedule, and plans of the Merikoski Hydropower Plant built on the Oulujoki river. Construction started in the spring of 1940. The planning was led by engineers and focused on power plant technology and the procurement of equipment and materials during the crises.

The power plant comprises a powerhouse, channels and reservoirs with multiple dams. The worksite contributed to the conversion of the Merikoski area into an industrial zone with the Oulu city centre on the south shore and the future Tuira garden suburb on the north shore. With the technical plans finalised and the work underway, more time could be afforded to town planning and landscaping.

The power plant’s functions and architectural modelling had already been decided, but a design competition was organised in 1942 for the facades and the surrounding area’s town plan. The competition area included vast swathes of land on both shores, as well as river islands and their bridges.

The competition programme emphasised the significance of the power plant as a new and progressive public building in the city of Oulu. Local beautification and recreation were on the wish list. A significant part of the task was the planning of economically relocating 300,000 cubic metres of earth excavated from the tailrace as close to the excavation site as possible.

The result of the competition was announced in December 1942. Two entries were received, from the firms of Bertel Strömmer and Alvar Aalto. Strömmer had put much effort into the power plant’s facades and was, therefore, commissioned to design them. Aalto had approached the design task from a broader perspective than even the competition programme had suggested.

In his overview, Aalto noted that Oulu was a city of two distinct districts separated by rapids and the estuary, which would now grow into a dynamic Greater Oulu. The water feature was a special characteristic of Oulu, akin to Paris, London or Florence, and it should be appreciated as such. This would be done by placing the developing city’s new centre and public buildings on the river islands, joining the old gridiron town centre and the Tuira district into one whole. In addition to the parks on the shores, the water mirrors and fountains that replaced the tamed Merikoski rapids would become principal features of the new landscape and scenery. Aalto was awarded the town planning of the area.

Aalto used the earth removed from the tailrace to raise, expand and shape the nearby islands. High-rise blocks were added north of the tailrace and to Toivoniemi, a former point expanded and shaped into an island. The Raatinsaari island received a sports ground and stadium, and Aalto created a public park around the Home Guard building on its west end, including the neighbouring Kuusisaari island. The Linnansaari and Lammassaari islands were to be combined and a town square with public buildings built on them. The square and buildings, along with the buildings on the east tip of Raatinsaari, would face a water mirror with fountains.

Aalto underlined that the islands should remain green and park-like. The river delta would be surrounded by a park zone with walking promenades. The Hupisaari park was considered valuable as it was and a part of the above zone.Aalto gave much attention to the traffic solution for the bridges crossing Merikoski. Bridges and streets were raised to be on the same level, and no intersecting traffic or stops were permitted on the bridgeway. A gate design leading to the bridgeway was created in the Koskitie intersection on the Tuira side.

Aalto stated that the power plant building itself would have a minor impact on the scenery, but that the buttress dam would dominate. In Aalto’s perspective drawing, the power plant is partially hidden by a tree and the buttress dam is reflected in the water mirror.

The town plan for the Koskikeskus district was completed in 1944. However, the squares planned by Aalto were never built, and the culture building cluster was actually placed on an island in front of the Kauppatori market square in a monumental centre designed by Marjatta and Martti Jaatinen. Regardless, for most parts the Koskikeskus plan has been realised as Aalto envisioned it. The bridges and traffic system principle remain functional solutions to date. The Raatinsaari sports centre has been supplemented by the recently built Kuusisaari recreation park. The residential blocks of Toivoniemi are the most photographed aspect of Oulu’s scenery, and since the area’s buildings were constructed in a short span of time, their character is highly uniform.

Although the water mirrors and fountains of Merikoski are only visible for part of the year, the park-like trails circling the estuary are nonetheless highly popular among walkers and joggers alike. The district’s name, Koskikeskus, is the one Aalto introduced in his plan. It is a signature area of Oulu, and it is easy to forget that it is actually an industrial area.

Text: Pia Krogius / City of Oulu