The Isar was well filled on Thursday afternoon in Bad Tölz. At its peak, 140 cubic meters per second flowed through the city. © Pröhl
The Isar currently carries significantly more water than usual. This is not only due to the heavy rain, but also to the control of the Sylvenstein reservoir.
Bad Tölz-Wolfratshausen – A lot of water is currently running down the Isar again. This is due to the rain, but also to the forward-looking control of Lake Sylvenstein by the Weilheim Water Management Office (WWA). As early as Monday noon, the dispensing volume was slowly increased. While 24 cubic meters per second flowed from the lake into the Isar on Monday, it was already 50 by Tuesday afternoon.
Discharge from the Sylvenstein reservoir into the Isar ramped up
At noon on Thursday, the output volume was ramped up to 90 cubic meters per second – "for a few hours," says Tobias Lang, who is responsible for storage at WWA. At the same time, 144 cubic meters per second poured into the lake.
As further precipitation is expected, the amount of discharge will increase even further in the next few days – to 120 cubic meters per second. This is completely uncritical for the downstream residents, but ensures that the retention volume in the reservoir remains large. In other words, the reservoir hardly fills up despite the continuous rain. But the increase in runoff has another effect, says Lang.
Levels of Lake Sylvenstein higher than usual at this time of year
Since there was no flood event last year, it is high time to provide a little dynamism. Silt comes loose, gravel is transported a little further, vegetation directly on the shore is washed away. All this also ensures that the habitats of fish and small creatures are cared for.
On Thursday afternoon, the lake level of the Sylvenstein cracked the 753-meter mark. That's three meters more than usual at this time of year. But: There really is still a lot of room for improvement. This became apparent relatively exactly ten years ago: On 3 June 2013, the lake level reached its highest level to date at 762.95 metres. At that time, the reservoir's controllable flood protection area was 99.7 percent full.
You can find even more up-to-date news from the region at Merkur.de/Bad Tölz.