You probably already know that Siljan is Sweden's 7th largest lake and that it is 135 m deep. The lake affects us who live in the parish. In the weather forecast, the weather is often divided between "north of Siljan" and "south of Siljan." It is said that thunder does not cross Siljan to Sollerön before midsummer and the water affects both wind and temperature. This year, Storsiljan washed away on Good Friday after offering fantastic skating ice during the spring winter.
But do you know how the water in the lake is regulated? During April there has been a "low tide". The rocky bottom between Sollerön and Gesunda is clearly visible and at the Sound the wading birds are looking for food in the sandbanks. Those of you who have planned to swim in the spring will have to walk far out because now it is extra shallow.
What causes the water level to vary so much?
Solleröbladet asked boat enthusiast Åke Ryss, who lives on the shore in Bråmåbo.
“Siljan first began to be regulated in the 1920s and since 1951 regulation has taken place at Grådadammen 20 kilometres downstream of Siljan along the Österdalälven River. The head there is actually only 0.5 m. In a Water Court from 1964, water regulation in Siljan and tapping of the dam in Trängslet were decided. The water level in Siljan can vary by almost 2 metres. The lowest the lake can be
159.90 m above sea level. The highest water level is 161.78. The ideal water level was determined to be 161.5.
Measurements of Sweden's large lakes take place daily all year round and can be followed on www.smhi.se
The water level is now increasing every day as the snowmelt has started in the mountains. Normal water levels are usually at the end of May.
Hydropower is valuable and power companies monitor water levels carefully to maximize the return on their investments. Today, regulation is handled by a computer stationed in Sundsvall.
Åke notices the water level for his tugboat M/S Orsa, which is today firmly anchored both at the jetty and on the bottom at the jetty. It comes loose when the water rises.
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