Tolkewitz waterworks

Aerial photo of the Tolkewitz waterworks in 2012

Tolkewitz waterworks (2011)

The Tolkewitz waterworks is located in the Tolkewitz district of Dresden , east of the city center. The waterworks , built between 1896 and 1898, provides almost 20 percent of the drinking water used in Dresden .

The capacity is around 35,000 cubic meters per day. The waterworks belongs to DREWAG - Stadtwerke Dresden GmbH .

location

The waterworks is located orographically to the left of the Elbe in the landscape protection area d 65 Dresden Elbe meadows and Dresden Elbe arms and in the drinking water protection area Tolkewitz (Zone 2).

history

1891 to 1899

Tolkewitz waterworks, from Wehlener / Tolkewitzer Straße

Due to the growing demand for water in Dresden at the end of the 80s and the beginning of the 90s of the nineteenth century, the efficiency of Dresden's first waterworks, the Saloppe waterworks (inaugurated in 1875), was soon reached. In 1891 the city administration commissioned building officer Bernhard Salbach (1833-1894) to draw up an appraisal for the future safe water supply of the city. In the same year a test well was built with a capacity of 4000 cubic meters per day. In addition, the City Council of Dresden bought part of the Elbe meadows on an old Elbarm from the property of the Tolkewitz parish council August Hähnichen. Two years later, with the construction of four more wells, the required output of 20,000 cubic meters per day was achieved. In addition, the suitability of the water as drinking water was proven. In early 1894, Salbach was commissioned to design the Tolkewitz waterworks. Construction could begin in autumn 1894. Above all, Italian construction workers were used for this. First, the flood-prone area was filled up. From mid-March 1898 the pump machines supplied by the Sächsische Maschinenfabrik Chemnitz were set up. On August 16, 1898, the waterworks fed water into the Dresden supply network for the first time.

At that time, the waterworks consisted of a siphon line with the connection of the wells, a collecting well with a well house, the machine house with two plunger pumps and the associated balancing steam engines, a boiler house, a coal shed and the transport system from the shipping pier to supply the plant with the required Coal. In addition, the work was given a stylistically aligned residential building on Wehlener Strasse.

As early as 1899 it became clear that it was necessary to double the capacity. With the construction of five more shaft wells, a second siphon line and a third pumping machine, a delivery rate of 40,000 cubic meters per day could be achieved.

1900 to 1985

In the following years, too, the plant was adapted to the respective needs and technical progress. A new filter hall with sixteen filters was built between 1913 and 1925, a third siphon line with 39 wells between 1919 and 1928, a chlorine system for disinfecting drinking water in 1921 and a system for deacidification using lime water from 1922 to 1925 . In 1925 the entire waterworks was electrified, and the pre-delivery and three new main delivery pumps could also be put into operation. Four years later, an aeration system and a sedimentation basin were built, between 1930 and 1936 systems for lime and carbon dioxide dosing as well as collection wells and between 1964 and 1968 a new pre-cleaning stage that worked with the excess lime process and represented a replacement for the outdated sedimentation basin. Between 1971 and 1985 the installation of new main feed pumps and the renovation or expansion of the electrical and MSR systems took place.

1989 until today

After reunification , water consumption in Dresden fell sharply. As a result, the water supply was stopped on April 16, 1992. On February 13, 1995 the operation of the entire waterworks was stopped. The reason for this was the heavily worn and outdated processing plants.

At this point in time, the renovation of the waterworks into a modern water treatment plant had already been decided. After extensive planning, the renovation began on February 17, 1997. The Saxon Ministry of the Environment had spoken out against restarting the plant by the city of Dresden. The reason for this was press reports about contamination of the Dresden groundwater. The Dresden Environment Department countered this by stating that the city's rich groundwater supplies guarantee a permanent and stable supply of drinking water. Environment Deputy Dr. Klaus Gaber considered financial interests of the Free State as the background for the accusations of the Ministry of the Environment.

The foundation stone for the new plant was laid on May 22nd. After almost three years, the waterworks went back into operation on February 22, 2000. The new, 27 million mark expensive system can produce a maximum of 35,000 cubic meters of drinking water. With the help of the multi-stage treatment, it was again possible to produce perfect drinking water. The new filter hall was built for 11 million euros on the site of the old ventilation system. The former chemical building was converted into an electrical center.

The listed building stock was used as much as possible during the construction work. All essential technology levels are housed in a newly constructed functional building. The filter stages are designed as concrete pressure bodies, whereby the structure of the filter is also the building's outer shell. This enabled the limited space between a residential area and the Elbe meadows to be optimally used.

When the Elbe flood in August 2002 , the entire waterworks was flooded. The damage was relatively small at around 200,000 euros. The plant was therefore able to resume work in September.

The old recirculator hall was demolished at the beginning of 2009. The 85 meter long and 15 meter high structure was erected between 1964 and 1968. Inside there were three huge containers with a diameter of 17 meters each and a capacity of around 1000 cubic meters. A mixture of bank filtrate and groundwater was pumped into this in order to bind dirt particles in a first cleaning stage by adding lime. Since the shutdown of the waterworks in 1995, the facilities in the hall have been out of order.

Since December 2009 the Tolkewitz waterworks has had modern automation technology. With the help of five industrial PCs , around 500 flaps, drives and pumps in the waterworks are controlled via the corresponding systems. It is therefore sufficient that the operation of the waterworks is monitored by two employees during the week and by one on the weekends. It also made it possible for the first time to program the computer during operation.

In 2010, two gate valves that control the inflow of groundwater to the wells had to be renovated.

During the floods in 2013 , the waterworks had to be taken out of operation and after ten days, two-thirds of its capacity could be fed back into the Dresden network. An extensive cleaning of the drinking water wells followed.

functionality

The raw water, which is processed into drinking water in the Tolkewitz waterworks, comes from groundwater and bank filtrate. 72 wells are available between Laubegast and Blasewitz for the extraction of groundwater from depths between 13 and 18 meters . The water is led from the well into a collecting well in the waterworks via a vacuum. Here the water is intensively aerated, with which chlorinated hydrocarbons are removed and oxygen is introduced. In addition, a flocculant is added to the water in order to retain colloidal and finely suspended ingredients in the water in the following filter bed. The water is pumped into a two-layer filter stage. Here residues of questionable trace substances are retained with activated carbon . Then the water, a chlorine dioxide - chlorine mixture to disinfection and sodium hydroxide solution added to the chemical Restentsäuerung. The prepared drinking water is then pumped into the Dresden supply network via two pure water tanks.

Functional levels

Tolkewitz socket with 3 siphon pipes, 56 drilling wells and 16 shaft wells for the extraction of bank filtrate
Collection well
Pre-delivery for the initial delivery of the raw water from the collecting well to the desorption system
Desorption system for intensive ventilation to remove chlorinated hydrocarbons and for oxygen enrichment
Intermediate tank for storing the water from the desorption columns
Intermediate delivery to raise the water on the multilayer filter
Flocculant system for storing and dosing iron (III) chloride for flocculating the colloidally dissolved substances
Sodium hydroxide system for storing and dosing caustic soda for pH regulation
Chlorine dioxide system for the production / dosing of chlorine dioxide for disinfection
Multi-layer filtration to remove iron and manganese compounds as well as colloidally dissolved substances
Activated carbon filtration to remove organic substances in water
Pure water tank for the intermediate storage of the drinking water produced
Pure water pumping for pumping drinking water into the supply network
Rinse water pumps for backwashing the multilayer filters and activated carbon filters
Rinsing water tank for water reserve for filter backwashing
Purge air fan for backwashing the multilayer filter
Buffer basins as intermediate storage for the filter flushing water
Waiting / transformer station
Social building
Farm buildings
Residential building
Former pre-cleaning facility

Individual evidence

↑ drinking water. In: dresden.de. State capital Dresden, accessed on August 23, 2015 .
^ Dresden-Hosterwitz waterworks . January 2008 ( online (PDF, 360 KB) [accessed February 14, 2014]).
↑ Information on Tolkewitz at dresdner-stadtteile.de, accessed on March 17, 2014
↑ Ministry of the Environment against restarting . In: Dresdner Latest News . February 20, 1997 ( online for users of the Dresden City Libraries [accessed on March 17, 2014]).
↑ The waterworks should only serve as a reserve . In: Dresdner Latest News . February 22, 1997 ( online for users of the Dresden City Libraries [accessed on March 17, 2014]).
↑ Tolkewitz waterworks back on the network . In: Dresdner Latest News . March 25, 2000 ( online for users of the Dresden City Libraries [accessed on March 17, 2014]).
↑ DWA invests eleven million marks in a new filter hall in Tolkewitz . In: Dresdner Latest News . May 23, 1997 ( online for users of the Dresden City Libraries [accessed on March 17, 2014]).
↑ Hosterwitz waterworks is back on the network . In: Saxon newspaper . January 25, 2003 ( paid online [accessed March 17, 2014]).
↑ Peter Hilbert: Desolate concrete hall in the Tolkewitz waterworks is demolished . In: Saxon newspaper . December 9, 2008 ( paid online [accessed on March 17, 2014]).
↑ New computers control the waterworks . In: Saxon newspaper . December 28, 2009 ( paid online [accessed on March 17, 2014]).
↑ M. Steimer: Well system in Tolkewitz is being renovated further . In: Saxon newspaper . September 29, 2010 ( paid online [accessed on March 17, 2014]).
↑ Hosterwitz waterworks is now back in operation . In: Saxon newspaper . June 24, 2013 ( online [accessed March 17, 2014]).
↑ Tobias Hoeflich: Wasserwerk Coschütz continues to work for three . In: Saxon newspaper . July 11, 2013 ( paid online [accessed March 17, 2014]).
↑ Simone Burig: Clean drinking water from Tolkewitz . In: Saxon newspaper . August 7, 2015 ( paid online [accessed August 8, 2015]).