2.5.04 Sustainable water management on the Volga – safeguarding the future of Europe’s longest river

At 3,500 kilometres, the Volga is Europe’s longest river. Massive intervention has altered the waterway on an almost unprecedented scale – with complex consequences for man and nature in the river basin. As part of a German-Russian project, sustainable solutions were developed for the economic and ecological management of the Volga and its feeder streams. The initiative focussed on water quality, water management and the safety of hydraulic structures.

The basinPart of the earth’s surface that is drained by a river and its tributaries. We distinguish between above-ground and underground basins. The drainage divide marks the boundaries of the basin. of the Volga with its approx. 200 feeder streams is the economic and cultural centre of the Russian federation and is home to around 40% of the population. Thanks to its water and resulting energy resources, the river offers enormous economic potential, which Russia has been exploiting for decades: as early as the mid 1930s, eleven large dams were constructed on the Volga and its largest tributary stream, the Kama. These structures (collectively known as the “Volga-Kama Cascade”) now generate a total output of 11 gigawatts. However, these massive interventions in the region’s ecosystem have resulted in far-reaching risks and conflicts.

The minimisation of these risks was the objective of the “Volga-Rhine project: a German-Russian joint venture for water quality and resource management on the Volga and Rhine” (period of study: 2004 to 2006). Funded by the BMBF and the Russian Research Ministry, the project involved a number of different parties: the Institute for Water and River BasinPart of the earth’s surface that is drained by a river and its tributaries. We distinguish between above-ground and underground basins. The drainage divide marks the boundaries of the basin. Management (IWG), the Engler- Bunte Institute (EBI), department of Water Chemistry, and the Institute of Concrete Structures and Building Materials (IfMB) of the Karlsruhe Institute of Technology (KIT), the Institute for Environmental Geochemistry of Heidelberg University and the Soil Physics department of the Helmholtz Centre for Environmental Research (UFZ) as well as the companies Voith Siemens Hydro (Heidenheim), MC-Bauchemie (Bottrop) and RusHydro (formerly RAO EES), Russia’s largest energy supplier. The project was co-ordinated by the IWG and EBI institutes of the KIT.

Precipitation and outflows analysed

Of particular significance are the statistical analyses and simulations of the precipitation/outflow behaviour in the Volga basin: how often and intensively does it rain? How does rainfall affect the natural outflow of the Volga? The relationship between precipitationIn this process, chemical reactions cause the transformation of dissolved substances into insoluble substances, which then settle at the bottom of a vessel or water body – e.g. in the form of flocs – where they can be more easily removed from the water. and outflow is of central significance to the entire river system: only when modelled on the basis of precise data, can accurate statements be made regarding the solute transport and highwater levels of the river.

To be able to analyse the flood zones, water depths and outflow during flooding, the scientists developed digital terrain models of five important barrages on the Volga. While the Russian contributors recorded and processed the available data, their German partners simulated the hydraulic conditions of the Volga using hydrodynamic numerical models. They also developed the program “Volga decision support system” to analyse different outflow scenarios. This program enables computer-based simulation of the entire Volga system and reservoirs, thus allowing the scientists to identify the most energy-efficient and ecologically sound management strategy for each barrage. To satisfy the various usage requirements for reservoir management, fundamental principles were devised for the simulation of barrage chains including automation functions for improved management.

Structures and water quality assessed

One of the main prerequisites for economical and environmentally friendly management of the Volga is the functionality and operational safety of the existing hydraulic structures. At the Volgograd hydroelectric station, scientists and engineers examined the condition of the structure and its individual components (weir overflows and pillars, concrete walls). The results of these on-site inspections and laboratory analyses then formed the basis for a restoration concept, the implementation of which was supported by the project partners with their combined technical expertise.

Although the former Soviet Union initiated extensive efforts to control its water quality in the mid 1940s, the results have never been published. Following the dissolution of the Soviet Union, these initiatives ground to a halt due to lacking materials and personnel. As a result, little is known about the current condition of the Russian waterways – despite the role of the Volga and other rivers as important sources of drinking water. The project thus also involved analyses of the pollutant content of Volga water and sediments. In the examined area of Nizhny Novgorod, the water quality was surprisingly good; introduced pollutants are greatly diluted by the massive water volumes transported by the river and contaminant levels reduced by self-cleaning processes.

Eutrophic reservoirs and their consequences

However, the nutrients in the water are leading to critical levels of eutrophicationExcessive input of nutrients, particularly phosphorus and nitrogen compounds, into standing or slow flowing water, thus resulting in the mass formation of algae and aquatic plants. The decomposition of dead plants and algae leads to oxygen depletion in the water and decay accompanied by the formation of hydrogen sulphide and other harmful substances (ecosystem collapse, fish kills, odours)., particularly in reservoirs; this is caused by the introduction of phosphorous compounds from household wastewater (e.g. detergents) and nutrient inputs from the agricultural industry. In the summer months, this eutrophicationExcessive input of nutrients, particularly phosphorus and nitrogen compounds, into standing or slow flowing water, thus resulting in the mass formation of algae and aquatic plants. The decomposition of dead plants and algae leads to oxygen depletion in the water and decay accompanied by the formation of hydrogen sulphide and other harmful substances (ecosystem collapse, fish kills, odours). is causing massive algae growth in reservoirs in particular; this in turn results in a reduced oxygen content of the water and the release of toxins. These effects are exacerbated by the relatively high concentrations of natural organic substances. The consequence: anaerobicAbsence of oxygen (O2). Also used in the context of organisms that do not require oxygen to live, or to describe chemical reactions that occur in the absence of oxygen. zones are appearing at many locations, which in turn leads to decomposition processes. Therefore, one of the main aims of the research project was to put the results to use, as a means of improving preventative measures and removing sources of pollution – for example, by practising ecological agriculture in the river basin.

Read more:

2.5.05 Mine rehabilitation at Ha Long Bay

Read more:

2.5.03 Drinking water quality in Iran