Waterworks Flehe
The Flehe waterworks is the oldest of four waterworks in the Düsseldorf area. It is located in the south of Düsseldorf . It is operated by Stadtwerke Düsseldorf . Approx. 7,590,000 m³ of drinking water are dispensed in the Flehe waterworks annually (as of 1998).
history
In 1866, a cholera epidemic in Düsseldorf killed 111 people. This catastrophe was the reason for the decision of the city council on June 23, 1868 to improve the unsanitary conditions in water procurement (rain collection systems, scoop and pump wells) by building a waterworks. After extensive economic calculations and hydrological investigations, test boreholes and an expert opinion by the Englishman William Lindley , the expansion of the water extraction and distribution systems began in 1869 according to plans by H. Schneider. The first station received two horizontal single-cylinder machines from the Magdeburg Steam Engine Company. 8,800 cubic meters of water was pumped per day, which was pumped through a 10 km long main pipeline to a 3,600 cubic meter elevated tank erected on the Hardt and from there distributed throughout the city.
On May 1, 1870, the first urban water flowed into Düsseldorf households. To control the central water supply, the city used the invention of the American painter Samuel Finley Breeze Morse , who had developed an electromagnetic telegraph . The telegraph line connected the waterworks in Flehe with the keeper's apartment at the elevated reservoir on the Hardt, the administration of the gas station and the town hall.
By 1924, water production in Flehe had grown to five separate pumping stations with 117 wells. The oldest pumping stations were already out of operation, so that only the fourth pumping station built in 1900/01, the fifth pumping station built in 1909/10 and the newly built electric pumping station met the main water requirements. The total daily amount was 80,000 cubic meters. The pipe wells are located at intervals of 20 meters along the Rhine at a distance of 50 m from the river bank. The electrically driven pumping station with a daily output of 40,000 cubic meters served as a reserve.
After the Second World War , the waterworks in Flehe and Am Staad were hardest hit of all the works. The elevated tank on the Hardt was also affected.
In 1949 , the Stadtwerke was the first company in Germany to sink a high-performance horizontal filter well on the site in Flehe, south of the Brücker Bach creek.
The last steam pumps in Flehe were replaced by electric motors in 1956.
From 1961 to 1967, treatment plants went into operation in the Flehe and Am Staad and Holthausen waterworks. When the "economic miracle" began, the obligation to always supply impeccable drinking water posed problems for the municipal utilities after a short time. Due to the water that seeped into the gravel and sands of the floodplain, the quality of the water in the wells deteriorated rapidly with the increasing pollution of the Rhine from 1949/50. However, as analyzes from 1961 showed, the well water always differed greatly from the Rhine water - thanks to the excellent natural filtering in the soil. As early as the twenties and thirties, increasing wastewater pollution of the Rhine and a gradually rising chloride content had been ascertained. Nevertheless, the well water was safe to drink without any treatment. Now the smell and taste of the water increasingly deteriorated. Industrial plants and cities led more and more wastewater into the Rhine. Of all the water treatment methods tested, the one with activated carbon and ozone worked best. After many years of trials, the construction of the first processing plant on Am Staad began in 1959. The Stadtwerke laid the foundation stone there for the first processing plant based on the "Düsseldorf processing method". It was put into operation in 1961 and delivered 6,000 cubic meters of drinking water “treated” with ozone and activated carbon every hour. Two more plants soon followed in Holthausen (1964) and Flehe (1967).
In November 1986, after the fire in the Basel chemical company Sandoz , the Flehe and Am Staad waterworks were temporarily shut down to protect the groundwater due to the population's fear of poisoned Rhine water. Strict checks of the groundwater and well water over several weeks by several scientific institutes finally showed that neither groundwater nor well water was damaged.
In 1990, the Rhine water control station built in cooperation with the State Office for Water and Waste was opened in the Flehe waterworks. In 1997 the Flehe waterworks was modernized. New water rights of 15 million cubic meters per year until 2027 for Flehe and of 22.5 million cubic meters per year until 2028 for the Am Staad waterworks have been granted.
Four pumping stations with six raw water pumps work in Flehe. Two pumping stations consist of 60 individual vertical wells that are connected to one another via a siphon pipe, the other two pumping stations are horizontal filter wells.
processing
The first stage is bank filtration. The second stage is oxidation by ozone : 0.5 g / m³, ozone generation from oxygen. Step three: pre-activation by means of activated carbon filtration in a closed construction, grain size: 1.5 - 2.5 mm, area: 20 m², height: 1.5 m, throughput: 200 m³ / h. Stage four is activated carbon filtration in a closed construction, grain size: 0.8 - 2.4 mm, area: 20 m², height: 2.5 m, throughput: 200 m³ / h. (Previously level 5: disinfection with chlorine dioxide : 0.05 g / m³.) And finally, level five: Inhibitors with phosphate : 1 g / m³ (previously also silicate: 1 g / m³). (As of 2016).
Coverage area
The drinking water supply area of the Düsseldorf waterworks comprises 600,000 people, trade and industry in Düsseldorf, Erkrath and Mettmann . In total, around 50 million cubic meters (m³) of drinking water are distributed in one year, which is an average of 140,000 cubic meters - 140 million liters per day. The daily charge varies between 120,000 cubic meters in winter and up to 250,000 cubic meters on a hot summer day.
biodiversity
The waterworks site ( water protection zone I + II) has always been used extensively ; it is not fertilized or treated with pesticides.
Areas in the landscape protection area : 44.30 hectares , of which high-quality meadow areas: 10.00 hectares (different intensities).
Area limitation: The biodiversity-relevant areas extend from the fence on Himmelgeister Straße on Brückerbach to the fence on Fleher Deich ( Fleher Bridge ). Beginning on the water side with a sharp edge from the paving or gravel embankment to the top of the dike. The top of the dike itself along its entire length. From the top of the dyke clean and sharp to the edge of the forest or to the Werkstrasse. On the Brückerbach dike (steep slope) from the side of the stream over the top of the dike to the first row of trees at the inner embankment foot.
The waterworks site consists mainly of FSC-certified forest. The south-facing meadow along the Rhine (area 1 of the picture on the right) and meadows along the Brückerbach (area 3 of the picture on the right) are the most species-rich meadows in Düsseldorf. A total of 81 plant species were recorded on the dike in Flehe. Including eleven species on the red list and three on the warning list. The meadows represent a very good expression of the now rare Stromtal semi-dry grassland (Thalicto-Brometum) (a relic of the Lower Rhine sage meadows). 21 typical species were found, e. B. Pigeon scabiosis (Scabiosa columbaria), meadow sage (Salvia pratensis) and medicinal thyme (Thymus pulegioides). Stromtal semi-arid grasslands are severely endangered according to the Red List of Plant Societies in North Rhine-Westphalia. They are also an FFH habitat type and a legally protected biotope type according to Section 62 of the North Rhine-Westphalia Landscape Act. This meadow community needs full tanning and two-tier mowing without fertilization. Through the drying of the mowing and the omission of the seeds in the meadows, as well as the subsequent removal of the hay, nutrients are removed. The species-rich Flehe site was able to develop over a period of 50 to 60 years.
Since a cooperation contract with the Biological Station Haus Bürgel in 2010, the meadows have been scientifically monitored. A floristic survey took place in 2010, a locust survey in 2012. The area around the Fleher waterworks is designated as a nature reserve in Natura 2000 and comprises 91.0 ha, of which 43.45 ha are public utilities. The meadows are particularly valuable.
There is also a transfer of cuttings and thus seeds for the new planting of grassland.
Web links
- From raindrops to the tap
- Drinking water treatment & supply
- Current drinking water analysis by Stadtwerke Düsseldorf
- Die Welt: The paradise behind the Flehe waterworks
- Formation and disappearance of the sage meadows on the Lower Rhine. By Karl-Heinz Knörzer
- Water management companies - active for biodiversity, options for action and good examples
Individual evidence
- ↑ a b Rüdiger Furrer, Michael Fleig and Heinz-Jürgen Brauch: Water pumping and treatment in the Rhine catchment area - IAWR. (PDF; 2.7 MB) (No longer available online.) Archived from the original on March 11, 2014 ; accessed on March 11, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ Stadtwerke Düsseldorf: Düsseldorf drinking water treatment and supply. Retrieved September 26, 2016 .
- ↑ Stadtwerke Düsseldorf: Clearly drinking water - basic material of life. (PDF) Retrieved September 26, 2016 .
- ↑ Biological station Haus Bürgel: Floristic study of the meadows in the waterworks Flehe and Am Staad with care instructions. (PDF; 3 MB) Retrieved October 12, 2015 .
- ↑ Biological station Haus Bürgel: Spread of locusts on the meadows in the Am Staad and Flehe waterworks with care instructions. (PDF; 1 MB) Retrieved October 12, 2015 .
Coordinates: 51 ° 11 ′ 7 ″ N , 6 ° 47 ′ 29 ″ E
