Lake Baldegg

Artificial Seebelüftung

Baldeggersee an 5.2 km ² large lake in the canton of Lucerne, in central Switzerland. It is located in the southern valley, nestled between the two elongated ridge of Erlosen in the west and the Lindenberg in the east. The average altitude is 463 m above sea level. M.; the deepest point of the sea floor is at 397 m above sea level. Level, which corresponds to a maximum depth of 66 m. The average depth of the lake is 33 m. Baldeggersee has a length of 4.5 km and a width of 1 to 1.7 km. Its water volume amounts to 0.173 km ³. He is one of the Pro Natura and is the largest Swiss lake is privately owned.

Inflows and outflows

The catchment area of the Baldeggersee is 73 km ² (including sea plane ). Main tributary is the Ron which opens at the south end of the lake. Furthermore, some small streams run on the western slope of the Lindenberg their water to the lake. Because all tributaries originate in the vicinity and therefore lead only a little water, the time of the mean water stay in the lake takes 5.5 years. The effluent is the Aabach, which leaves the lake at its northern end and empties into the Hallwilersee after a few kilometers. The shores of the lake are relatively flat on all sides. Only municipality directly on the lake is Gelfingen; the two slightly larger places Hitzkirch and high village are set away from the lake at the foot of the Lindenberg.

Formation

Owes its existence to the Baldeggersee the glacial Reuss glacier, which had ground out and übertieft today's Valley. At the retreat of the glacier remained here for a long time a so-called Toteiskörper lie that prevented the mound of overdeepened valley floor with river sediments.

Environment

Baldeggersee located in an agriculturally intensively used area. Thus, the lake was exposed since the 1920s, a burden of over-fertilization (phosphorus, nitrates, ammonia). Furthermore, the time still unpurified wastewater from settlements and industry were added. This problem could be solved by the construction of sewer systems. In contrast, the nutrient input from agriculture became greater during the 20th century, which finally led to a rapid growth of algae and, consequently, to the strong decrease of the oxygen essential for the Sea ecosystem.

A combination of various measures had since 1980 the goal is to improve water quality. On the one hand, farmers were encouraged by educational work and financial incentives from the federal and canton to limit the accumulation of nutrients in the lake by greener economies. On the other hand, the Baldeggersee is ventilated artificially since 1982 the world's first lake. With this artificial oxygenation, the oxygen content was increased almost to the legally required 4 mg of oxygen per liter of water. In winter, with compressed air which is fed in at the seabed, forces a forced circulation of the water. This allowed the phosphorus content of the lake will be reduced by 2010 to about 26 mg / m³. However, the aim is a value between 15 mg / m³ and 20 mg / m³.