Hosterwitz waterworks

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Hosterwitz waterworks (2011)
Old building complex by Hans Erlwein (2016)

The Hosterwitz waterworks is located in the Hosterwitz district of Dresden , east of the city center. The waterworks , which was built between 1905 and 1908 according to plans by City Planning Director Hans Erlwein , provides around 20 percent of the drinking water used in Dresden .

The capacity is around 72,000 m³ per day. The waterworks belongs to DREWAG - Stadtwerke Dresden GmbH .

location

The waterworks is located orographically to the right of the Elbe in the nature reserve 2 Dresden Elbe valley slopes and in the drinking water protection area Hosterwitz (zone 1).

History and functioning

Filter halls of the Hosterwitz waterworks (right river water filter hall; left pure water filter hall with ventilation cascades)
New building complex with pure water tank and ventilation system
Machine house
Flocculation / sedimentation
Filtration through grain charcoal

The Hosterwitz waterworks went into operation on December 11, 1908 after a year and a half of construction as the third Dresden waterworks after the Saloppe waterworks (1875) and the Tolkewitz waterworks (1898). The city planning director Hans Erlwein drafted the plans for this.

At the opening, the water treatment technology used was the extraction of groundwater enriched with bank filtrate . The extracted water was then pumped directly into Dresden's water distribution system. Due to the increasing demand for drinking water in Dresden, an expansion of the waterworks became necessary, which was carried out between 1928 and 1930. The aim of the conversion was to be able to supplement the existing natural groundwater supply (the amount of water available to the system) if necessary. For this purpose, Elbe water, i.e. surface water, was pumped out, then seeped away through gravel beds (whereby it was pre-cleaned) and then taken again through wells. In addition, a new filter stage was built to treat all of the raw water. It had become necessary because the Elbe water quality dropped significantly due to pollution. The quality of the drinking water threatened to decline as well. The new filters counteracted this. During the expansion, steam was also replaced by electricity as a driving force .

In the 1970s, the capacity of the Hosterwitz waterworks had again become too small. After intensive preliminary investigations, a fundamental renovation began in 1983. The aim was an increased drinking water output of up to 72,000 cubic meters per day. This was achieved by building new technological modules, especially high-performance processing stages.

After the fall of the Wall , further improvement measures were carried out. A further increase in water quality was achieved by commissioning a filter system with activated carbon .

Even today, the system can draw its raw water from 3 sources: from natural bank filtrate, as well as the groundwater that has been increased through artificial infiltration and also from the landside inflow. In Dresden this is a unique selling point of this waterworks.

Erlwein building

The old factory halls designed by Hans Erlwein were in operation from 1908 to 1992. Since the buildings are under monument protection , the operating facilities were moved to a new building between 1983 and 1992. The old buildings remained as empty industrial monuments. In the years after the move, the exterior of the building was restored to its original state. In 1994, the reconstruction of the roofs began. In doing so, they got the dormers , the beaver tail covering and copper gutters provided by Erlwein back.

The social and office area of ​​the waterworks is now located in the old hall for filtering river water. In the former machine house there are pumps for the supply of the Dresden high altitudes, for example from Weißig .

The former pure water filter hall is rented to a branch of the technology center water of the German Association of Gas and Water . Inside the hall, the architect Eberhard Pfau built a house within a house. The hall is not completely filled by the office wing. From the free space you can see how the old roof towers over the new inner building. In addition to the office wing, space in the hall is reserved for additional technical systems.

Current condition of the waterworks

Fountain in the Hosterwitz waterworks

After the Elbe floods in 2002 , 5.3 million euros were spent on repairing the damage to the waterworks located directly on the Elbe. The pumps as well as the chemical storage and dosing systems were repaired. In addition, the electronic measurement and control technology and the power supply had to be replaced. After four and a half months of repairs, the waterworks could go back online.

Many of the 144 wells that are still active today date from 1932 to 1934. 100 cubic meters of water per hour can be extracted from each well. The depth of the wells is up to 22 meters with a diameter of two to three meters. The wells have been gradually being renovated since 2007. The current maximum processing capacity is 72,000 cubic meters per day. In 2015, ten million cubic meters of water were treated, half from raw water from the Elbe and half from free groundwater inflow.

The sand must be removed from the infiltration basin and cleaned every 20 years. Around 1500 cubic meters of sand are washed in a mobile cleaning system with excavators. Weeds, dirt and other contaminants are removed here.

The waterworks was expanded between 2015 and 2020. Among other things, a large pumping station and three sludge tanks were built in which sludge from the bank filtrate of the Elbe can settle. This means that the pre-cleaning of the bank filtrate no longer has to be interrupted to dispose of the sludge. The aim was to increase the maximum daily processing capacity to 107,000 cubic meters. In addition, the control electronics were relocated in a flood-proof transportable container and an inner dike was built. The costs totaled around 6.4 million euros.

Functional levels of the Hosterwitz waterworks

Aerial photo of the waterworks (2010)
front: flocculation sedimentation, back left: old waterworks, back right: chemicals building, ventilation system
  • Elbe water extraction with inlet structure for pumping Elbe water into flocculation and sedimentation
  • Flocculation and sedimentation to eliminate coarse impurities and reduce all other ingredients
  • Filtration (infiltration) to remove the turbidity and particles
  • Infiltration to eliminate microorganisms
  • Well for the collection and removal of bank filtrate and infiltrate
  • Ventilation system for deacidification by discharging carbon dioxide and introducing oxygen
  • Filtration over grain coal to eliminate dissolved trace substances
  • Pure water tank for intermediate storage of drinking water
  • Nacelle with intermediate delivery pumps, filter rinsing water pumps, rinsing air blowers and pure water pumps for pumping the drinking water into the distribution network of the city of Dresden
  • Chemical building for storage and dosing of aluminum sulfate and caustic soda
  • Chlorine system for storage and dosing of chlorine for drinking water disinfection
  • Buffer basin for intermediate storage of the filter rinsing water

Individual evidence

  1. ↑ drinking water. In: dresden.de. State capital Dresden, accessed on August 23, 2015 .
  2. ↑ Hosterwitz waterworks . January 2008 ( online ( memento from March 4, 2016 in the Internet Archive ) [PDF; 366 kB ; accessed on April 13, 2020]).
  3. ↑ Article on Dargebot on lw-online.de, accessed on May 31, 2013
  4. ^ Stefan Rössel: New life in the Erlweinschen halls . In: Saxon newspaper . September 1, 2006 ( online [accessed April 13, 2020]).
  5. ↑ Hosterwitz waterworks is back on the network . In: Saxon newspaper . January 25, 2003 ( online [accessed April 13, 2020]).
  6. ↑ Kay Haufe: Wells in the waterworks are being renovated . In: Saxon newspaper . July 8, 2010 ( online [accessed April 13, 2020]).
  7. ^ Tilman Günther: Hosterwitzer waterworks renovates wells . In: Saxon newspaper . December 12, 2009 ( online [accessed April 13, 2020]).
  8. ↑ Dirk Wurzel: Record number of visitors to the 100-year-old waterworks . In: Saxon newspaper . December 17, 2008 ( online [accessed April 13, 2020]).
  9. ↑ a b Kay Haufe: Hosterwitz waterworks gets in shape for emergencies . In: Saxon newspaper . May 9, 2016 ( online [accessed April 13, 2020]).
  10. ↑ Washing is done in the waterworks . In: Saxon newspaper . December 15, 2011.
  11. ↑ Peter Hilbert: Dresden waterworks become more efficient . In: Saxon newspaper . April 29, 2020 ( paid online [accessed April 30, 2020]).
  12. ↑ Peter Hilbert: Test for new systems in the waterworks . In: Saxon newspaper . July 27, 2020 ( paid online [accessed on July 31, 2020]).

Web links

Commons : Wasserwerk Hosterwitz  - Collection of images, videos and audio files

Coordinates: 51 ° 1 '20.3 ​​"  N , 13 ° 51' 0.6"  E