BORÅS RIVER
Tolken
Viskan is a river that is 142 km long and runs through the southwestern parts of Sweden. It begins its long journey in Tolken, a lake that is situated on the border between the municipalities of Ulricehamn and Borås. The lake is the largest its hydrological system and is surrounded by a varied landscape, such as forests and open fields. It is lacking in nutrition and is therefore sensitive against eutrophication.
There are no major sources of pollution nearby, but Tolken is receiving unidentified emissions from for example private drains and acid rain. However, thanks to the relatively nutritious environment, the lake handles this acidification rather well.
Borås
The next larger lake that Viskan forms is lake Öresjö, situated to the north of Borås. This lake is the main water supply to the city. The river then runs trough Borås and along its sides you can find several famous textile industries. These industries have shaped the city for centuries.
Borås was founded in the year 1622 by the great King Gustavus II Adolphus. Over the years, Viskan has been affected by both domestic and industrial waste. It has been said that Viskan during the mid 20th century resembled all the colours of the rainbow. This was caused by the textile industry that released their polluted water into the river without any purification whatsoever.
Further downstream, Viskan forms two lakes, Djupasjön and Guttasjön as well as one dam, the Rydboholms dam. Studies performed on the deep layer sediments of these waterways have shown that this is one of the most polluted areas in the entire country. This is a result of decades of hazardous pollution emitted from the different industries.
Seglora
After the power plants in Viskafors and Svaneholm lie the marches of Seglora. At this point the river begins to flow calmer while growing wider. Viskan then meanders slowly through the rural landscape where wetlands are common. The marches play a vital role in the ecosystem and works like a buffet, preventing flooding at high flows.
Häggån
Between the urban areas of Kinna and Skene, Viskan merges with another river, Häggån.
The outflow
Viskan reaches the sea at Klosterfjorden.