Rubbish in the Rhine river: What the ‘Rheinkrake’ study reveals about waste in our waters

The Rhine is a habitat, a transport route and one of Europe’s most important links to the North Sea. At the same time, it carries large quantities of waste. Such river pollution has not previously been systematically investigated. A recent scientific study now shows that the scale of the problem is significantly greater than previously assumed: every year, an estimated 27 to 42 million pieces of macro-litter flow down the Rhine towards the North Sea. This equates to around 3,000 to 4,700 tonnes per year. 

These findings were made possible by the ‘Rheinkrake’ in Cologne – a specially developed waste trap that continuously collects macro-litter floating on the water’s surface or just below it. For the WEPA Foundation, this project is an important example of how environmental research, civic engagement and concrete responsibility for water protection can be meaningfully combined – which is why the WEPA Foundation has been supporting the Rheinkrake for several years now. 

The Rheinkrake Study: How much rubbish the Rhine carries towards the North Sea each year

The study is based on a 16-month survey period during which the ‘Rheinkrake’ was emptied regularly between September 2022 and January 2024, and the collected litter was scientifically analysed. For the statistical year from November 2022 to November 2023, 17,523 macro-litter items were recorded. The adjusted weight was around 1.1 tonnes. Based on this data, it was calculated that the Rhine near Cologne carries an average of around 53,000 macro-litter items per day. 

Particularly relevant: around 70 per cent of the items found are made of plastic. At the same time, the majority of the waste originates from private consumption. Around 40 per cent of all macro-litter consists of single-use products, primarily fireworks debris, drink lids and snack and confectionery packaging. More than 99 per cent of the waste recorded comes from land – not from the water itself. The results clearly show the extent to which our use of packaging and single-use items is harming the environment. 

 
  • The Rhine carries an estimated 27 to 42 million pieces of macro-litter towards the North Sea every year – around 53,000 pieces of litter per day. 
  • This equates to around 3,000 to 4,700 tonnes of macro-litter annually. 
  • Around 70 per cent of the items found are made of plastic. 
  • Around 40 per cent of the litter consists of single-use items. 
  • The 15 most common waste categories account for around 74 per cent of all macro-litter – this is where there is significant scope for effective countermeasures. 

The Rhine Octopus in Cologne: How the litter trap provides data on macro-litter in the Rhine

The Rhine Octopus was developed by the K.R.A.K.E. e.V. association and installed in Cologne. The structure consists of two collection baskets with a total width of three metres, which are connected to the bank via a floating guide fence. This ensures that floating litter is directed into the system. The litter trap enables the continuous and relatively robust collection of macro-litter – a significant step forward for monitoring rivers as a pathway into the oceans. 

A key element of the project is the citizen science approach: volunteers regularly empty the ‘Rheinkrake’, sort the items found according to international standards and record them digitally. It is precisely this collaboration between science and voluntary work that makes such high data quality possible. The study also shows that rising water levels significantly increase the volume of litter and that more waste is collected in winter than in summer. Such findings help to plan prevention and clean-up measures in a more targeted manner. 

The WEPA Foundation and Rheinkrake: The role of funding in research and water protection

The WEPA Foundation supports the Rheinkrake project, thereby helping to enable an initiative with a long-term impact. Its funding not only bolsters scientific data collection, but also environmental education, voluntary work and public awareness of water protection. It is precisely this connection that reflects WEPA’s core values: taking responsibility, valuing resources and promoting sustainable action where it makes a tangible difference. 

Why the findings of the Rhine Octopus study are relevant to the Rhine, the North Sea and environmental protection

The study not only provides new figures, but also concrete starting points for effective water protection. If the 15 most common types of waste were specifically targeted for reduction, the total volume of macro-litter in the Rhine could theoretically be reduced by more than 70 per cent. At the same time, the study shows that rivers such as the Rhine must be given greater attention when it comes to protecting the seas and coasts – and that we must recognise that our handling of waste has far-reaching consequences even in places that are supposedly far away. 

For WEPA, one thing is clear: sustainability requires knowledge, partnerships and a willingness to take action. The ‘Rheinkrake’ brings to light what would otherwise remain hidden. And it demonstrates how important it is not merely to identify environmental problems, but to tackle them through research, education and shared responsibility. 

Reason for hope: the ‘Rhine Octopus’ remains in service

The researchers are already working on new analyses – and we at WEPA will continue to support this fantastic project. But one thing still makes all the difference: that we take responsibility ourselves, handle waste carefully and consume more thoughtfully, for the sake of our rivers and the environment as a whole. 

- WEPA Group

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