The Merikoski hydroelectric power plant was built along the Merikoski rapids at the mouth of River Oulujoki. The power plant was built by the City of Oulu and finished in 1948.

The city started the construction in the fall of 1939 with earth-moving works. The construction of the dams and canals were also started. In 1942, the building board decided to organize an architecture competition where the participants were asked to draw a plan of the whole district and design the general architectural features and façades of the power plant. Three architects were summoned to take part and Alvar Aalto and Bertel Strömmer returned their proposals.

The competition was settled in December 1942, and Aalto was declared winner with his “Koskikeskus” plan. The plan was partly implemented during the 1940s and 1950s.The board preferred Strömmer’s power plant design, so he was given the task to design the facility. In the site plan, the power house was placed between the north bank of the river and the tip of Toivoniemi, an artificial island. In 1942, the power house was already largely designed from a hydroengineering standpoint. Strömmer’s task was to find the right architectural means for the overall appearance and arrange the facility into the cityscape. In the Finnish Architectural Review 1–2/1943, Strömmer explains: ”Because of mechanical and electric-technical circumstances, the architect’s role will be quite limited in laying out the organization and the overall masses.”

Strömmer cladded the concrete-framed building with plastered brick and articulated the main façades with tall vertical windows, ending up with a solid piece of clearly articulated modern industrial architecture that blends his classicist tendencies and curiosity towards Functionalism.

Comparing the current power house to Strömmer’s competition entry, one can notice certain differences, especially in the south façade. The ribbon windows were not realized and the section that connects the power house to the longitudinal buttress dam, has a reduced mass compared to the drawing. Also, the classicist colonnade entrance was not built.

The south façade forms a fitting ending to the concrete dam. The section that is cladded with natural stone joins the dam elegantly to the base of the power house as the plastered finish intertwines with the headrace. The view from the south also reveals the articulation of the building. The section next to the tailrace contains the control rooms, technical spaces and offices. The large block in the middle holds the three generators. The lower block next to the headrace is the main gate hall, which contains the radial gates that control the water flow to the turbines. The regulating dam is located at the other end of the longitudinal buttress dam and has two spillways gaps.

In 2003, a fish ladder was built. It passes the power house and regulating dam from the south side.

Text: Samuli Paitsola