Wikipedia
Partnach
The Partnach is a 16.5 km long Bavarian mountain river. It rises at a height of on the Zugspitze Massif. The Partnach is fed by meltwaters from the Schneeferner glacier some 1100 m higher up. The glacier’s meltwaters seep into the karsty bedrock and reach the surface again near the source of the Partnach.
The Partnach then flows down the Reintal valley. Until 2005 there were two mountain lakes here – the Vordere and Hintere Blaue Gumpe. At the first lake the water of the Partnach was impounded by scree from rock slides. As a result of heavy rain the natural dam, caused by rockfalls, was partially carried away and the lake was completed filled with sediment. As a result the Blaue Gumpe does not exist any longer today.