Free waters for the fish of Lake Mälaren

En stadsmiljö sedd uppifrån. Staden ligger vid en sjö och delas på mitten av en brunfärgad å. Det är tät bebyggelse med en större väg, gator och en järnväg. Vid ån finns träd och gröna gräsytor. Vid sjön syns ett hamnområde med många fritidsbåtar och två större bostadsområden med höga flerbostadshus.

Waterways have always been hugely important to people. Many Swedish cities emerged around streams, brooks and rivers that were important for transport, electricity supply and other activities made possible by the power of the water.

The Svartån river, one of the most important waterways for fish and other animals living in Lake Mälaren, flows through Västerås. The fauna passage built in 2018 diverts water past the power plant dam and opens up the habitat for over 30 different fish species in Lake Mälaren. Now they can swim upstream in the river and spawn. In the first year alone, more than 800 fish were captured on the camera used by the fish counter – including the red-listed asp, which can grow to a length of 120 cm.

We now have more of an understanding of the importance of flowing waterways for aquatic life and biodiversity. Opening up fish migration routes makes a huge difference, and the rushing water adds a vibrant new element to the urban environment.