Rivers are the planet's most significant freshwater resource, which sustain entire ecosystems, ensure the diversity of flora and fauna, and create favourable conditions for human existence. However, it is often the result of human economic activity that proves devastating both to the river and to everything located on its banks.

Various organisations publish "their own" lists of the dirtiest rivers every year. The number of rivers included in the lists may vary, as may the type of pollution used to include a river in the list. However, there are rivers that have been found in all of these lists for at least the last ten years. They are united by one thing - the rivers flow through densely populated areas with poorly developed waste management infrastructure and intensive industry.