Harjavallan Hydropower Plant was built at the municipalities border of Harjavalta and Nakkila in 1939. Th epower plant works with two vertical Kaplan turbines which combine capacity is 72 MW. Dam height and the waterfall is about 26.5 meters, powerful sight if you happen to be at the area as they open the by pass doors of the Dam.
The Plant's turbines are run entirely by remote control from the Tampere central control. Driving models are affected by the water situation, permit conditions for decisions and economy. In 2014 the Dam was under the renovations, third smaller turbine was added next to the existing ones, to balance the energy supply during flood peaks.
Annual production is about 400 GWh. A fish hatchery has also been planned in connection with the plant.