(Kopie 3)

2009

Fishery checks of the Ruhr Fishery Association and the North Rhine-Westphalian Agency for Nature, Environment and Consumer Protection discover more than 20 examples of true young salmon in the Ruhr near Mülheim-Raffelberg in June. For over 100 years, salmon had completely disappeared from the Ruhr. Their return is the result of sustainable water management which helped to continuously improve the Ruhr's water quality during the past years.

(Kopie 2)

2009

Chronology of the Ruhrverband

1863	On December 3, the city council of the city of Essen agrees on building the first water catchment facility in the Ruhr valley.
1864	On October 20, the waterworks in Essen starts operating.
1867	The waterworks in Witten starts operating.
1880	More than 100 waterworks are being set up in the Ruhr valley between 1880 and 1900.
1883	Robert Koch discovers the bacterium causing cholera, which is being transmitted via drinking water.
1897	Annual water abstraction from the Ruhr amounts to 135 million cubic metres.
1899	Waterworks and power plant operators found the Ruhrtalsperrenverein as a voluntary association.
1901	A typhoid epidemic breaks out in Gelsenkirchen. Robert Koch, acting as a consultant on the disease’s containment, speaks out in favour of establishing an institute for hygiene, which until today is located in Gelsenkirchen.
1903	Annual water abstraction from the Ruhr amounts to 197 million cubic metres.
1904	The Fürwigge Reservoir stars operating on March 24, the Ennepe Reservoir on December 5.

Laying the foundation stone of the Fürwigge Reservoir on October 3, 1902.

1906	On December 6, the decision is taken to build the Möhne Reservoir. Construction starts on January 7, 1908.
1910	Dr. Karl Imhoff, who will later become managing director of the Ruhrverband, draws up the report "Keeping the Ruhr clean".
1911	Drinking water conditions along the Ruhr are catastrophic during this extremely dry year. A typhoid epidemic breaks out in Mülheim, infecting 1,500 people. Annual water abstraction from the Ruhr rises to 412 million cubic metres.
1913	An act on keeping the Ruhr clean (Ruhrreinhaltungsgesetz), based on Imhoff's report, is being published in the Prussian law gazette on June 5, creating the legal basis for sewage treatment along the Ruhr, of which the Ruhrverband takes responsibility. Enacted on the same day, an act on the Ruhr reservoirs (Ruhrtalsperrengesetz) controls water quantity management along the Ruhr and turns the Ruhrtalsperrenverein into a public body. The Möhne Reservoir is inaugurated on July 12, constituting at that time the largest reservoir in Europe.
1925	The first sewage treatment plant in continental Europe with activated sludge treatment starts operating in Essen-Rellinghausen.

Up to the mid-1920s, sewage ran through the streets in open canals in many cities of the region, just like here in Menden.

1926

The Ruhrtalsperrenverein starts building the Sorpe Reservoir. The Ruhrverband starts constructing Lake Hengstey.
Annual water abstraction from the Ruhr amounts to 513 million cubic metres.

The first laboratory of the Ruhrverband was located in a regular room in the St. Annental part of Essen-Rellinghausen.

1929	The Ruhr region goes through another extremely dry year. In order to avoid the catastrophic consequences of such weather conditions in future, the construction of several repump stations, designed to transport water from the River Rhine up to Essen if needed, is being initiated. Lake Hengstey is the first out of eight planned impounding lakes to be finished. According to Imhoff’s plan on how to keep the Ruhr clean, they are designed to foster the river’s natural purification.
1931	Lake Harkort is the second impounding lake of the Ruhr to start operating. Construction of Lake Baldeney starts right during the world economic crisis as a so called emergency measure, meaning that most of it is done through manual labour. In peak times, up to 2,000 unemployed find work on the construction site. The largest impounding lake of the Ruhr, with a surface of 2.65 square kilometres, is completed in 1933.
1934	Dr. Karl Imhoff, since 1922 managing director of the Ruhrverband, is forced into retirement by the National Socialists. Throughout the country, he is considered the most important expert on sewage engineering and also enjoys international recognition. After eight years of construction, the Sorpe Reservoir starts operating. The construction site of its 700-metre-long dam was at times the largest construction site in Europe.
1938	On December 20, the decision to build the Bigge Reservoir is taken. 19 years, however, go by until construction starts, another eight years until the reservoir is finished.
1939	The start of the Second World War disrupts construction of the Verse Reservoir which had only started a year before. During the war, construction is taken up again and carried out resorting to forced labour from inmates of the labour education camp Hunswinkel. Around 550 of the camp’s prisoners die from hunger, abuse or shooting during the war. The Verse Reservoir can only be completed in 1951 after 13 years of construction. The Hunswinkel camp disappears under the water when the lake is impounded. Today, a memorial at the Klamer Bridge commemorates the victims' suffering.
1943	In the night from May 16 to May 17, a British bouncing bomb tears a hole into the dam of the Möhne Reservoir. 1,500 people die in a flood wave up to seven metres high. The Eder Reservoir in Northern Hesse is also being destroyed during this night. The Sorpe and the Ennepe Reservoir, however, resist the bombing sustaining only minor damages.

View of the left Möhne banks near Neheim after the Möhne Reservoir's destruction.

1947	Extreme droughts cause the water to retreat to an alarmingly low level. The series of repump stations has been completed up to Lake Baldeney and provides people along the lower Ruhr with water from the Rhine.
1949	The Ruhrtalsperrenverein celebrates its 50th anniversary with a ceremony at the Verse Reservoir.

Participants in the ceremony on the occasion of the Ruhrtalsperrenverein's 50th anniversary.

1955	A mechanical sewage treatment plant starts operating in Duisburg-Kaßlerfeld.
1958	A two-stage biological sewage treatment plant goes into service in Essen-Werden.
1959	Once again, a dry year leads to water shortages. The situation is worsened by the fact that the Sorpe Reservoir has been completely emptied to repair the damages of war. The series of repump stations along the Ruhr is being extended by three more stations up to Bochum-Dahlhausen. The repump stations in Winz, Hattingen and Blankenstein, however, are never completed; the planned stations Herbede I and Herbede II never realised.
1963	The coal crisis - already developing since the late 1950s - comes to its first peak when 13 mines are being shut down. The closures mark the end of the region's mining tradition lasting over two centuries. The consequences can still be felt today. Groundwater infiltrating the gigantic network of pits and tunnels stretching underneath the entire Ruhr region has to be pumped off around the clock - a continuous challenge of water management in the region.
1964	In late 1964, an act on detergents comes into force as a result of the increasing usage of detergents containing tensides from the mid-1950s, causing heaps of foam to appear on rivers and streams. It stipulates that detergents may only contain tensides which are at least 80 per cent biodegradable. The Central Detoxification Plant (ZEA, today Central Disposal Plant) goes into service in Iserlohn. It takes care of the pre-treatment of liquid wastes, which in the early years mostly came from the region's metalworking industry and its crafts enterprises.

The usage of "hard detergents" leads to heaps of foam on streams and rivers. The picture shoes the Mühlenbach stream in Rellinghausen.

1973	The increasing load of nutrients such as phosphor and nitrogen in the Ruhr leads to massive algae growth. The excessive growth of plants affects drinking and industrial water treatment, puts the fish stock at risk and causes the lakes to silt up. Dr. Hans Werner Koenig, managing director of the Ruhrverband and the Ruhrtalsperrenverein, publishes a memorandum on the "rising threat to drinking water supply from the Ruhr". In his exposé, he explains that in future, water supply can only be safeguarded if it goes hand in hand with water management and land use planning measures. Koenig is particularly worried about the increasing degree of soil sealing.
1975	The Ruhr Water Quality Report (today Ruhr Quality Report) is being published for the first time. From this year on, it appears annually, consistently monitoring the continuous improvement of the Ruhr's condition.
1978	The Ruhrverband increasingly uses effluent polishing ponds for tertiary treatment in its sewage treatment plants. The largest effluent polishing pond with a surface of 360,000 square metres is being completed at the sewage treatment plant in Bochum-Ölbachtal.
1979	Lake Kemnade goes into service on August 1. It is the fifth and last of originally eight impounding lakes to be created along the Ruhr according to the plans of Dr. Karl Imhoff. Since sewage treatment has meanwhile improved significantly, Lake Kemnade is from the beginning not primarily built to reinforce the river's natural purification but mainly for recreational purposes.
1983	After 50 years in service, Lake Baldeney is being excavated to keep it from silting up. An overall 1.1 million cubic metres of sediment are removed from the lake and transported to two spoil areas in the Heisinger Aue floodplain. In November, the Henne Reservoir only reaches one fifth of its filling level at maximum impoundage. Old streets and bridges appear in the dried-up areas.

Streets and bridges appear in November 1983 in the upper parts of the Henne Reservoir.

1986	The Rahmedetal sewage treatment plant starts operating the Ruhrverband's first aeration system with targeted denitrification.
1990	Based on a law enacted on February 7, the Ruhrtalsperrenverein merges with the Ruhrverband, so far responsible for water quality management. From July 1, the new water association takes on the name Ruhrverband.
2000	Elodea nuttallii, an aquatic plant native to North America, appears in Lake Harkort. In the following years, it spreads to Lake Hengstey, Lake Kemnade and Lake Baldeney. Stronger plant growth is facilitated by the rising water quality of the Ruhr. Since the water has become much cleaner in recent years, sunrays can now filter through to the ground. But the plant affects water sports and other activities. Therefore, the Ruhrverband tries to find a long-term solution, for instance through a research project supported by the North Rhine-Westphalian Department for Environment. Until today, however, all attempts to get a grip on the plant have been rather unsuccessful.
2003	On March 21, the Ruhrverband opens the "Historical Collection of Ruhr Water Management" inside a former gas transfer station next to the sewage treatment plant in Essen-Rellinghausen. It serves professional training purposes and is also open to guided tours.
2005	The Ruhrverband concludes its 1.5-billion-euro investment programme with the new construction of the sewage treatment plant Essen-Süd. Since 1990, this money had been used to modernize all sewage treatment plants in a way that they can to a large extent retain phosphor and nitrogen.
2007	On January 18, a storm named "Kyrill" sweeps across Central Europe with winds of up to 225 kilometres per hour, causing desastrous damages, especially in the Sauerland and Siegerland regions. In the Ruhrverband's forests alone, around 400 hectares of trees fall victim to the storm within only a matter of hours. The reforestation of this area, mainly with oak and beech, takes two and a half years.

Damages caused by the storm "Kyrill".

2009

Young salmon in the Ruhr.

Ruhrverband | Kronprinzenstraße 37 | 45128 Essen | Telefon 0201 178-0 | E-Mail info@ruhrverband.de