Sonnaz (river)
Sonnaz | ||
The Sonnaz flows into the Schiffenensee |
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Data | ||
Water code | CH : 272 | |
location | Canton of Friborg ; Switzerland | |
River system | Rhine | |
Drain over | Saane → Aare → Rhine → North Sea | |
Headwaters | in the area of the Seedorf plain between the cities of Freiburg and Payerne | |
Source height | approx. 610 m above sea level M. | |
muzzle | below Pensier (municipality of Barberêche ) in the Saane ( Schiffenensee ) Coordinates: 46 ° 50 ′ 41 ″ N , 7 ° 8 ′ 27 ″ E ; CH1903: 577 285 / 188219 46 ° 50 '41 " N , 7 ° 8' 27" O |
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Mouth height | 532 m above sea level M. | |
Height difference | approx. 78 m | |
Bottom slope | about 6 ‰ | |
length | approx. 13 km |
The Sonnaz is an approximately 13 km long left tributary of the Saane (French Sarine ) in the Swiss canton of Friborg . It drains a section of the central Freiburg Plateau and belongs to the catchment area of the Rhine . The stream was first mentioned in 1317 as Sonna .
The headwaters of the Sonnaz are located in the area of the Seedorf plain at 610 m above sea level. M. about halfway between the cities of Freiburg and Payerne . Several rivulets, including those that arise on the northern slope of the La Brillaz ridge , flow into the Lac de Seedorf near Noréaz . The Sonnaz leaves this lake to the east and flows through a well-developed valley, which is flanked by the Molasse hills north of Freiburg, where it soon takes a north-easterly direction and maintains this until its mouth.
Especially in the lowest section in the area of today's municipality of La Sonnaz (the stream gave its name to the municipality that was created on January 1, 2004 through the merger of Lossy-Formangueires , La Corbaz and Cormagens ), the Sonnaz flows through a wide valley basin. Until 1963 , it flowed below Pensier (municipality of Barberêche ) into the Saane, which is now dammed up to become Schiffenensee (532 m above sea level). The gradient of the Sonnaz is usually less than 1%.
Sections of the middle and lower reaches of the Sonnaz are still in their natural or near-natural state. In the agricultural areas of the Lake Village Plain and near Belfaux , the water was straightened and the embankments paved. The Sonnaz is characterized by a pluvial runoff regime . In the past, their hydropower was used to power mills in various places.