Schwarza (Black Forest)
Highlighted during the Schwarza
The Schwarza between reservoir Witznau and Leinegg
The Schwarza is the largest river in the river system of Schlücht, the parts of the Black Forest to Wutachschlucht and High Rhine towards dehydrated. After leaving the Schluchsee it flows in a southeasterly direction a narrow and lonely wooded valley.
- 2.1 Hydropower
- 2.2 traffic
- 2.3 Minerals
- 3.1 Schluchseewerk before the damming
- 3.2 Mining 3.2.1 Lead and silver mining
- 4.1 cards
Geography and topography
Course
As Schwarza the flow starts only below the dam Schluchsee district Breisgau in the Black Forest at about 890 m above sea level. NN. Its natural headwaters is the Ahabach with which the Schwarza including the lake crossing is 29.3 km long. Before the damming of the natural Schluchsee to its present size and height ( about 930 m above sea level. NN ) flowed through the Ahabach before flowing into the lake in many turns the big box moss, bringing the total length of the Schwarza was bigger. Today, from the headwaters of the Wutach, the Seebach and Haslach, 1.5 m³ / s of runoff diverted and the Windgfällweiher and then open forwarded in a long hidden Hangkanal Schluchsee. Other tributaries of the Schluchsee are the Fischbach and Krummbach. The Ahabach rises to about 1260 m above sea level. NN in the southeastern Bärhalde ( 1318 m above sea level. NN ).
The Schwarza flows below the dam by one to 400 meters deep incised, largely empty settlement narrow valley through the basement (older granites ) of the Black Forest. The upper part is through the formation by ice-age glaciers a moderately broad glacial valley, below the largest right tributary stream, the Fohrenbaches, it goes into a V-shaped valley. The part of the valley with rocky upper slopes steilhängigste is referred to as the black heaps. Despite the rejuvenation by Ice Age glaciers, the valley has a regular slope. In the district of Waldshut in Witznau (municipality Uhlingen birch village), opens the Schwarza in the Schlücht.
Water management
On its entire run, the Schwarza is involved in hydroelectric power plants, so that it shows its natural water supply anywhere. When leaving the Schluchsee has the Schwarza already a natural water supply (without input and output lines ) of approximately 1.5 m³ / s At the confluence with the Schlücht the Schwarza is not only longer ( 29.3 km compared with 21.3 km ), but also significantly greater ( 2.6 m³ / s compared to 1.5 m³ / s), so that they hydrologically the main river Schlücht the system is.
Lakes in the river course
In addition to the Schluchseewerk are two more reservoirs in Schwarzatal. These two equalization tanks have short term fluctuating water levels and are therefore not suitable for leisure uses.
Reservoir Schwarza Bruck
The reservoir Schwarza Bruck is about 6.2 km, measured from the dam Schluchsee from downstream to approximately 725 m above sea level. NN and is dammed by a 40 m high dam. The approximately 0.1 km ² artificial lake is about 500 m long and 275 m wide.
Reservoir Witznau
The dam of the reservoir Witznau located approximately 1.25 km upstream of the mouth of the Schwarza in the Schlücht. The reservoir reaches a width of up to 120 m and covers the former course of the river for a distance of approximately 1.1 km. The surface of the lake reaches almost 0.1 km ² and is located about 470 m above sea level. NN.
Use and development
The valley is primarily used for forestry. Because of the altitude and high inclination of the valley slopes, however, is greatly limited the use in larger sections. From the sloping valleys between Brenden and Berau area of over 300 ha are designated as forest reserve since 1971. Tourist of the beautiful valley is little used, which allows an undisturbed nature experience. The western route of the Black Forest hiking trail leads through the middle Schwarzatal.
Hydropower
The greatest significance of the valley lies in the use of hydropower. It forms, with its reservoirs, the major axis of the pumped storage network Schluchseewerk -Werke AG, which is sufficient to Waldshut from Schluchseewerk about belonging to the reservoirs or pumping power plants Schwarza Bruck and Witznau to the Rhine.
Traffic
For public transport with motor vehicles, the valley of the Schwarza is only partially accessible. A county road (K 6561 ) from the south ends after about 4.5 km. One the the rest of the valley following narrow, very uniform rising road stands, next to the traffic, only forestry, cyclists and hikers open.
Minerals
In Schwarzatal, especially on the ridge between Schwarza and Mettma, there is next occurrence of fluorspar, used in the manufacture of fluorine and fluorine compounds, including deposits of galena, associated with silver, both of which were mined in the past (see below).
History
Schluchseewerk before the damming
Before the completion of the dam of the Schluchseewerk existed a natural " Ursee ". The outflow of Schwarza was then about 500 meters further north at the former Seebrugg. This had elongated lake (name within the meaning of hose Lake ) has a length of about 3 km (now about 7 miles), an area of 1.03 km ² ( 5.13 km ² today ) and was about 900 m ü. NN (now 930 m above sea level. NN ).
Mining
Lead and silver mining
In Schwarzatal the outcropping on the slopes veins were in the Middle Ages, and probably much earlier, degraded. It was mined for silver, but that could be won only by the reduction of the silver-bearing galena. The Won Name Silberberg below the village Buggenried (municipality Grafenhausen ) goes back to this degradation. In a small side branches that are at the former hamlet Leinegg below the castle Leinegg get above the Fohrenbachmühle old galleries but they are not accessible.
The degradation was operated in the Middle Ages from St. Blaise monastery or imposition of a charge, which the government was involved from the front Austria. The mined galena was then smelted in Wurkehof in Todtnau and brought the raw silver recovered in a hut in Freiburg im Breisgau to higher fineness. Busy is the use of silver as coinage in Freiburg's coin. Lead was used in the Middle Ages, among others in the construction of windows, stone connections or sheets.
The degradation of minerals came with imports cheaper silver already at the end of the Middle Ages more and more to a halt. In the 20th century (especially in 1900, 1922-1926 and around 1939 ) Probeschürfungen were made mainly in the east adjacent Mettmatal, but also in Schwarzatal. However, it did not lead to renewed degradation.