Interdisciplinary Colloquium: Where does the clean water from my tap come from? – A drinking water reservoir in focus

A contribution from the field of biology




The Interdisciplinary Colloquium offers (young) scientists at the University of Koblenz the opportunity to present themselves and their research projects to a broad university public and to engage in conversation, get to know each other and exchange ideas. The scientific topics of the lectures are presented in a comprehensible way and made accessible across disciplines in order to contribute to the scientific culture on campus.


Securing clean drinking water involves a comprehensive series of steps. These include selecting a water source, installing an underground pipe system, and extracting, purifying, and analyzing the water. The Wahnbach Reservoir is an important drinking water source in the region Bonn/Rhein-Sieg/Ahr, supplying more than 800,000 inhabitants.

Long-term monitoring data provided by the Wahnbachtalsperrenverband (WTV) enables a precise water quality and quantity analysis. Investigating the development of key parameters of the water along its depth profile over time helps to understand underlying processes and interdependencies with environmental changes. An increase in surface temperature, shift in stratification, and lack of mixing at the end of summer are observed. This, together with changes in reservoir operation, impacts raw water quality. As part of the continuing project, chemical, physical, and biotic data are compiled to closely examine the water quality. Additionally, regular field studies and laboratory analyses of water and sediment samples are carried out. Hereby, a special focus lies on the manganese cycle and the occurrence of microorganisms. Manganese can cause aesthetic and technical problems. Especially, the manganese-associated organisms are relevant for the manganese cycle, so the yet not fully characterized microorganism “Metallogenium” is regularly detected in the reservoir by microscopic analysis. The impact of “Metallogenium” and other microorganisms on the conversion of different metals such as manganese and their occurrence in the Wahnbach Reservoir are scrutinized.




In cooperation with the CZS Mint-Forum