Forsliden Dam, Tallån River, Västerbotten County, Sweden

Hydropower dam removed in Sweden thanks to the Hydropower Environmental Fund

Tallån Catchment & River
Tallån River, tributary of Rickleån River, is located in Skellefteå Municipality, Västerbotten County, Sweden. It comprises a catchment area of 162,731 km² (Figure 1). It springs from Tallträsket and runs for 15 km before flowing into Bygdeträsket. It is inhabited by several fish species, including trout (Salmo trutta) and grayling (Thymallus thymallus), as well as the endangered river pearl mussel (Margaritifera margaritifera).

Figure 1. Location of Tallån River, Sweden

Forsliden Dam
In August 1854, the authority at the time issued the construction of a sawmill in Forsliden and of a dam on Tallån River (Figure 2) to provide water to power it. The original sawmill (Figure 3) was operative till the end of the 19^th century. Due to the gradually increased demand and value of wood, the sawmill was being upgraded from time to time and remained operative till 1951, when it was demolished.

Figure 2. Location of the Forsliden Dam at Tallån River, Sweden

Figure 3. The Forsliden sawmill in 1968 (photo by power plant owner)

The Forsliden Dam (Figure 4) was also providing water to a mill that was built in 1870 and remained in operation until 1914-1915. In 1922, after WW I, the Forsliden Electricity Association was formed by 13 villagers from Rotsjön and Forsliden aiming to provide electricity to the farms in both villages. Thus, the old mill had to be replaced by a power plant (Figure 5). Around 1930 the villages of Fäboliden, Tallträsk and Björnliden also begun to receive electricity from this power plant. The energy consumption of each house was relatively low, and 13.000 kWh were sufficient for the 23 subscribers at that time, with an average price of 10 øre/kWh.

Figure 4. Painting of the 1920 Forsliden Dam at owner’s house (photo by Christer Borg)

Figure 5. Old power plant in Forsliden (photo by Lage Johansson)

The demand for electricity grew rapidly and in 1957-1958 and the hydroelectric power station was once again upgraded. The power station was damaged during a spring flood in 1970 but was restored afterwards. In 1990 it was struck by thunder and decommissioned soon after. The hydropower plant was later acquired by Forsliden Energi and in 2009 renovation works began. After two years of renovation and upgrading the power plant became from a fully manual operation to a fully automated, state-of-the-art facility. The latest Forsliden Dam was built on the same site as the original dam from 1854 (latitude: 64,46587286, longitude: 20,22132193). It was a 7-m wide dam, made of concrete (Figures 6-7).

Figure 6. Forsliden Dam at Tallån River (photos by (left) Christer Borg and (right) Magnus Hagström)

Figure 7. Forsliden Dam at Tallån River (photo by power plant owner)

Barrier removal process
In December 2016, the owner of the Forsliden Dam and power plant, Karl Jonsson TTT AB, applied for a permit that was rejected by the Environmental Court. The main hearing was held in Skellefteå District Court on May 22-23, 2019. The owner eventually agreed to the power plant decommission and removal of all structures in December 2020 and applied to receive financial compensation up to 95% of the production loss to the Vattenkraftens Miljöfondde (Hydropower Environmental Fund). He received approval six months later, in June 2021. In August 2021, the owner received permission under Chapter 11 of the Environmental Code for excavation and demolition of both structures. Prior to the removal works, the court had ordered the preparation of a cultural-historical documentation of the site, which was written by Christer Borg and Dr. Margaretha Svenning, NAP2.0, 2021 (currently MKS, Miljö och Kultur i Sverige). The removal works took place during the summer of 2022 (Figure 8) and were finished in August (Figure 9; Video 1).

Figure 8. Demolition works of the Forsliden Dam at Tallån River in summer 2022 (photo by Richard Löwall)

Figure 9. Removal site at Tallån River after the demolition of the Forsliden Dam in August 2022 (photo by Christer Borg)

Video 1.

Ecological and community benefits
The removal has benefited all fish species and the river pearl mussel. Natural sedimentation has also been restored and is now transported in a natural way along Tallån River. Future benefits in terms of recreational angling and similar activities are expected.

Before & After photo pair

The removal site at Tallån River: (left) before and (right) after the removal operations of Forsliden Dam (photos by Christer Borg)

With many thanks to Dr. Margaretha Svenning and Christer Borg, MKS (Miljö och Kultur I Sverige) for providing the information and some of the photographs presented herein.

Written by Foivos A. Mouchlianitis