In earlier times, the entire Oelbachtal was a marshy brook valley in which the Oelbach could change its bed. Karl Leich reported in the Bochumer Heimatbuch in 1954 that beavers used to live in the valley.
Here is the source of the Stenbocksiepen stream. This flows into the Harpener Bach. The Oelbach begins at the confluence of the Harpener Bach and the Langendreerbach and ends in the Ruhr.
The Oelbach was also known earlier in its course under the names Meeßbach, Blennebach, Mühlenbach, Dorfbach, Hevener Bach or Aulbach. The name Oelbach is derived from the old name Aulbach. This Aulbach had its source in the Oberdorf of the Bochum district of Langendreer and flowed through the three parts of the village, before then going to the Ruhr in what is now the bed of the Oelbach.
In the past, the water power of the Oelbach was also used to drive water wheels:
• The Lady of Bönen's scythe hammer • Meesman Hammer • Mill of the House of Heven • Reckhammer at Haus Heven • Oil mill at Haus Heven • Dönhofer Mühlen (also called Mehlings Mühle) • Luhn's Mill • Luhn's Hammer
The Aulbach disappeared from the canal system due to mining and development. The still existing Köttelbecke called Langendreerbach is just an overflow channel for high loads on the canal in rainy weather.
The formerly numerous collieries, Lorraine, Amalia, Caroline, Prince of Prussia, Robert Müser, Vollmond, Colonia, Mansfeld, Urbanus, Klosterbusch and Dannenbaum, drained their pit water, especially waste water from the coal washing plant, into the stream. In order to recover the high proportion of fine coal in the water and to clarify the water, ponds were built that were later renatured or filled in. The Harpener Teiche and the Ümminger See, which today serve as rainwater retention basins, have been preserved.
Due to the sewage and mountain subsidence, the stream was often clogged or burst its banks and affected the meadows of the residents. Therefore, from 1904, the Oelbach and its tributaries were straightened and channeled. Before the confluence with the Ruhr, two tailings ponds were built, which had to give way when the Kemnader See was built.
Today, the Oelbach carries away sewage from households and industry as well as mine water.
The body of water has water quality 3, which means it is heavily polluted. The start of renaturation is not to be expected in the next few years.