This list contains rivers and other streams that have been regarded, currently or historically, as among the most polluted in the world due to their quantity of pollution, the severity of different components of the stream's pollution, its impact on the local population, or a combination of all factors.
Africa NameLocationDependent populationDescriptionSources of pollutionImpactAkaki RiverCentral Addis Ababa, Significantly high contaminant concentrations in the rivers.Waste disposal site of Addis Ababa, Ethiopia's largest city.Rural population downstream of the main city put at risk of health issues.Awash River18.6 million Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International LicenseInternationally famous for its high density of hominin fossils. Inscribed on the UNESCO World Heritage List in 1980.Industrial and urban wastes, agricultural runoff (pesticides, fertilizers), and sewage discharge.Severe ecosystem damage.Imo RiverSoutheastern Reported by the World Health Organization as one of the most polluted rivers in Nigeria.General Manager Emeka Ugoanyanwu issued a public warning that that locals should not dispose of trash, urinate, bury the dead, and build soak-away pits along the river, due to it polluting the river with coliform bacteria.Severe risk of making the main source drinkable water for Owerri non-potable.Modjo RiverCentral One of the two most polluted rivers in Ethiopia.Habtamu Dugo, "Environment in Peril in Oromia, Ethiopia", Independence Institute website, published 8 May 2009Wondwossen Sintayehu, "Action Professionals’ Association for the People vs. Environmental Protection Authority: Report on the Public Interest Litigation Case instituted at the Federal First Instance Court of Ethiopia" , submission to the Thematic Workshop on Governance, Civil Society Participation and Strengthening Partnerships for Chemicals and Waste Management and SAICM Implementation, United Nations Institute for Training and Research (accessed 24 April 2011)Toxic industrial chemicalsNairobi RiverThe rivers are mostly narrow and highly polluted,Ndiritu, G. G., N. N. Gichuki, P. Kaur, and L. Triest. 2003. The Nairobi river is mainly used by local citizens for bathing, washing clothes, and cleaning their homes. Characterization of environmental gradients using physicochemical measurements and diatom densities in Nairobi River, Kenya. Aquatic Ecosystem Health & Management, 6 (3): 343-354. though recent efforts to clean the rivers have improved water quality.Agriculture, slums, and industry.Olifants River and Close to the historical area of the Pedi people, Sekhukhuneland.Green algae and very high sulphate levels attributed to coal mining and industry in the upper catchment.Osun RiverOsun State, One of the river goddesses in Yorubaland. In 2018, the river suddenly began to change color due to gold mining. The river recorded the highest level of microplastics ever reported in river water globally in early 2024.Plastic pollution, heavy metals and cyanide contamination as a result of illegal gold mining, and human generated waste.Threatening the Osun Osogbo Sacred Grove.
Asia +NameLocationDependent populationDescriptionSources of pollutionImpactBharalu RiverAssam, One of the most polluted rivers in the state of Assam. The biochemical oxygen demand of the river is 52 mg/L compared to the permissible limit set by the National River Conservation Directorate (NRCD) of 3 mg/L.Guwahati city's municipal wastes.The obnoxious smell generated by the river is also a health hazard for the residents of Guwahati.Buckingham CanalConstructed during British rule, no longer used due to rail and road travel. The most polluted waterway in Chennai.Sewage and effluents from industry and agricultural in Chennai, including North Chennai Thermal Power Station. Nearly 60% of the estimated 55 million litres of untreated sewage produced by Chennai is dumped into it daily.The silting up of the canal left the water stagnant, creating an attractive habitat for malaria-spreading mosquitoes.Buriganga RiverDhaka, Economically very important to Dhaka. Ranks among the most polluted rivers in the country.Chemical waste of mills and factories, household waste, medical waste, sewage, dead animals, plastics, and oil, primarily among nine industrial areas lacking industrial wastewater treatment plants.Citarum RiverWest Java, ~5,000,000Longest and largest river in West Java, Indonesia. Described by the Asian Development Bank as the world's most polluted river.2,000 industries, primarily textile factories, contaminate 5,020 sq miles of the river with over 20,000 tons of waste and 340,000 tons of wastewater daily. Toxins include lead, mercury, arsenic, sulphites, nonylphenol, Phthalates, PCB 180, paranitrophenol, and tributylphosphate.Elimination of a significant part of the river's fish population, estimated at 60% since 2008.Cooum RiverTamil Nadu, 9,000 familiesCalled "a stinking cesspool" in poetry and journalism. A World Bank-funded project shows that it is 80 per cent more polluted than treated sewer water.An estimated of untreated sewage from government agencies like Chennai Corporation and local businesses, leading to high faecal coliform bacteria, pesticide, lead, zinc and cadmium levels.Fish were able to survive in the water for only 3 to 5 hours even after samples were diluted. Almost zero dissolved oxygen.GangesTens of millions of peopleThe most sacred river to Hindus. Levels of thermotolerant coliform bacteria from human waste in the river near Varanasi are more than 100 times the Indian government's official limit.Failure of the Ganga Action Plan due to corruption and poor planning/expertise.Main article: Pollution of the GangesGhadir RiverSouthern Beirut region, About 120,000 inhabitants in the Hayy El-Sellom neighborhood.The most polluted river in Lebanon, described in 2017 by Lebanese minister of public works Youssef Fenianos as no longer normal water, but sewage water.Industrial zones by the river.Floods of sewage water in settllements near the river, leading to periodic displacement. Believed to contribute to elevated rates of asthmatic and skin diseases, especially in children.IlekAktobe Region, , and Orenburg Oblast, .Илек, Great Soviet EncyclopediaThe most polluted water body in the Ural-Caspian basin."Water resources of Kazakhstan in the new millennium," Water Resources Committee of RK, 2002Boron and chromium in the river caused by the tailing ponds of former chemical plants via ground water.Indus River, , Birthplace of the Indus Valley Civilisation in the Bronze Age.