Lehnmühle dam
Lehnmühle dam | |||||||
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Dam wall of the Lehnmühle dam | |||||||
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Coordinates | 50 ° 49 '43 " N , 13 ° 35' 37" E | ||||||
Data on the structure | |||||||
Construction time: | 1927-1931 | ||||||
Height above valley floor: | 43.6 m | ||||||
Height above foundation level : | 50.6 m | ||||||
Height of the structure crown: | 525.6 m | ||||||
Building volume: | 170,000 m³ | ||||||
Crown length: | 521 m | ||||||
Crown width: | 4 m | ||||||
Power plant output: | 0.60 MW | ||||||
Data on the reservoir | |||||||
Altitude (at congestion destination ) | 517.96 m | ||||||
Water surface | 135 ha | ||||||
Storage space | 21.9 million m³ | ||||||
Total storage space : | 23.1 million m³ | ||||||
Catchment area | 60.4 km² | ||||||
Design flood : | 83 m³ / s |
The Lehnmühle dam is a dam in the Free State of Saxony . It is located in the Eastern Ore Mountains in the Saxon Switzerland-Eastern Ore Mountains district between the cities of Frauenstein and Dippoldiswalde . The dammed body of water is the Wilde Weißeritz, which rises on the ridge of the Ore Mountains .
history
Several flood disasters in the 19th century , in particular the severe flood in the summer of 1897, prompted the Saxon state government to establish effective flood protection in the Eastern Ore Mountains to protect the cities of Dresden and Freital . At the same time, the reservoirs were supposed to guarantee the drinking water supply of the cities mentioned. After the construction of the Malter dam (1908–1913) and the Klingenberg dam (1908–1914), the Lehnmühle dam was the third structure in the years of the global economic crisis .
The dam was built from 1927 to 1931. The dam wall consists of gneiss quarry stones that were extracted in two nearby quarries. The technical equipment came from the Polte works . Due to the construction of the dam, the road from Schmiedeberg to Frauenstein had to be redrawn. The road (now Bundesstraße 171 ) swung south in a large curve and crosses the dam on a dam with a passage at the upper end of the reservoir.
In 1959 a power plant with a Francis turbine was installed at the dam , which has been generating electricity since 1965. The turbine output is 600 kilowatts. Between 1975 and 1990 the dam wall was extensively refurbished with new grouting on the water side and the top of the wall renewed. The operating facilities (bottom outlet line, extraction lines, electrical equipment) were renewed between 1998 and 2000.
Steinbrückmühle
In the area of today's reservoir there used to be the small settlement Steinbrückmühle around the eponymous watermill, including the sawmill and the so-called Kreherschmiede . The flooding of this settlement began in the course of a snowmelt in January 1932 - a few months earlier than originally planned. At that time, the settlement's restaurant, smithy and sawmill had not yet been completely cleared, so that the residents had to be evacuated by boat.
The so-called Zinnstrasse formerly ran over the Weißeritzbrücke at the Steinbrückmühle from the tin ore mines in Altenberg and Niederpöbel to the smelting plants in Freiberg . This old tin bridge 50 ° 49 ′ 10.9 ″ N , 13 ° 35 ′ 30 ″ E over the Wilde Weißeritz is still preserved and can be seen up to a dam level of about 30%, e.g. B. in 1975 and 2018.
Lehnmühle
Below the dam was the Lehnmühle , which gave the dam its name. The water mill, which worked as a grinding and board mill, was first mentioned in a document in 1536. At that time it belonged to the Hennersdorfer Lehngut and was later also subject to the Reichstädt manor . A wood grinding shop was set up here around 1870. After the Second World War , an oxygen plant was set up in a building, which later became an agricultural machinery manufacturer. The water management department of the dam used another building from the old mill until 1978. The buildings were demolished at the end of 2006 due to vacancy and decay. Today a small rest area with an information board reminds of the old Lehnmühle.
Dam wall
The dam wall of the Lehnmühle dam was one of the first straight quarry stone walls in Europe. To this day it is the only straight gravity dam made of rubble stones in the new federal states . It is a "large dam" according to ICOLD criteria .
use
Together with the Klingenberg dam dam Lehnmühle serves primarily drinking water supply of Dresden , in addition, the flood control and to a lesser extent the electricity .
The dam is surrounded by an approx. 100 meter wide protective forest of coniferous trees (hardwood species could not be planted because of the risk of pollution from fallen leaves and decay). Around the Klingenberg-Lehnmühle dam system there is also a drinking water protection area of almost 90 km 2 (area number T-5370019), of which around 60 km 2 are accounted for by the Lehnmühle dam, whose protection area extends into the Czech Republic . A nature trail with 16 information boards leads from the Lehnmühle dam to the Klingenberg dam.
For reasons of drinking water protection, swimming and recreational sports are prohibited in the reservoir. Fishing is possible if the water management restrictions are observed.
gallery
Voluntary labor service of the Reichsbanner at the dam in December 1931
Installation of dam valves by the Polte works
Extremely low water level at the end of August 2018 with the Steinbrückmühle bridge now visible
See also
Individual evidence
- ↑ see old map of this area
- ^ Exhibition on the Lehnmühle dam, local researcher Rico Dittrich, Hartmannsdorf
- ^ Historical maps of Saxony
- ^ Sächsische Zeitung: A sunken village appears again , August 16, 2018
- ↑ Anglerverband Elbflorenz Dresden e. V. - Lehnmühle dam
literature
- Eastern Ore Mountains (= values of the German homeland . Volume 10). 1st edition. Akademie Verlag, Berlin 1966.