Ebrie Lagoon and Komoe River

A brackish lagoon system bordering Abidjan, Ivory Coast's largest city and economic capital, connected to the Atlantic at the city itself and to the outlet of the Komoe River to the east. Global emission inventories place this outfall among the world's highest ranked, a reflection of how a metropolis built around a coastal lagoon shortens the path from street waste to open ocean.[1]

Last reviewed: July 20, 2026 Reviewed by: Plastic Bank Research Team

Why This River Matters

In the Meijer et al. 2021 inventory of 31,819 modeled outfall points, the Ebrie Lagoon and Komoe outfall ranks #21 worldwide, with a modeled emission of 3,304 metric tons per year. That places a West African lagoon mouth above many rivers with far larger basins and far greater name recognition. The study's central finding explains why: more than 1,000 rivers account for 80% of global riverine plastic emissions, and the highest-ranked outfalls tend to drain dense coastal cities rather than long continental rivers.[1]

Abidjan grew up around the Ebrie Lagoon rather than beside a single river mouth, and that geography matters in the model. Waste generated along the metropolitan shoreline enters a water body that already sits at the ocean's edge, exchanging water with the Atlantic at the city and joined to the outlet of the Komoe River to the east. Meijer et al. found that short distances between waste generation and the coast sharply raise the probability that mismanaged plastic reaches the sea, and few settings compress that distance more than a city built around a coastal lagoon.[1]

Rainfall does much of the moving. Southern Ivory Coast has a tropical climate with pronounced wet seasons, and the downpours that swell the Komoe also flush Abidjan's streets and drains, delivering litter to the lagoon in pulses. In the underlying model, precipitation and wind are the forces that mobilize land-based plastic into waterways, so basins with energetic wet seasons rank higher for a given amount of mismanaged waste.[1]

Behind the transport story sits a waste management story. UNEP describes a recurring pattern in fast-growing coastal cities: collection services that cannot keep pace with settlement and consumption, leaving open drains and informal dumps as default disposal routes. Abidjan concentrates Ivory Coast's commerce, packaging, and port logistics along the lagoon, which multiplies the material at stake, and the responses UNEP outlines for such settings, extending collection into underserved districts, formalizing waste recovery work, and cutting single-use packaging upstream, map directly onto a lagoon-front metropolis.[2]

A high rank is a modeled estimate, not a measurement. The figure of 3,304 metric tons per year is a midpoint within a global total that Meijer et al. bound at 0.8 to 2.7 million metric tons per year, and individual rankings shift as waste, rainfall, and river flow data improve. What is unlikely to change is the underlying lesson: where a major city, a lagoon, and the ocean meet in one place, the path from street to sea is short, and this outfall is among the clearest West African examples of it.[1]

Key Facts

What Drives Emissions Here

Shoreline density in Abidjan. Ivory Coast's largest city wraps around the lagoon, placing homes, markets, and commerce at the water's edge, so uncollected waste has almost no distance to travel.[2]

Collection gaps amid rapid growth. Waste collection in fast-growing West African cities often lags settlement expansion, and UNEP identifies open drains and informal dumps as the default routes for what goes uncollected.[2]

West African wet season pulses. Heavy seasonal rains swell the Komoe and flush the city's storm drains, mobilizing accumulated street litter into the lagoon in concentrated bursts.[1]

Direct opening to the Atlantic. The Ebrie Lagoon exchanges water with the Gulf of Guinea at Abidjan, so plastic reaching the lagoon can pass onward to the open ocean instead of being retained inland.[1]

Port and market waterfront. Abidjan hosts one of West Africa's major seaports, and freight handling, fishing, and market activity concentrate packaging and gear along the lagoon's shore.[2]

Methodology Note

Figures cited are modeled estimates from global-scale studies; they are not direct measurements from continuous monitoring of plastic flux at the Ebrie Lagoon and Komoe River mouth. Improving local waste data and field campaigns may refine these values. Use this profile to understand systemic drivers and regional context, not as a definitive audited mass balance.

Ebrie Lagoon and Komoe River FAQ

How much modeled plastic emission is associated with the Ebrie Lagoon and Komoe River?

This profile reports 3,304 metric tons per year for the Ebrie Lagoon and Komoe River in the Meijer et al. (2021) global river plastic emissions framework. The value is a modeled annual estimate, not a continuous field measurement at the river mouth.

Is the Ebrie Lagoon and Komoe River one of the most polluted rivers in the world?

For plastic specifically, the Ebrie Lagoon and Komoe River ranks #21 of 31,819 modeled river outfall points worldwide in Meijer et al. (2021). "Most polluted" has no single definition, and this dataset models plastic transport to the ocean rather than overall water quality, so the ranking is best read as a plastic-specific indicator, not a general pollution verdict.

Which rivers rank near the Ebrie Lagoon and Komoe River globally?

Among the named rivers in the dataset, the Bharathappuzha River (#20) sits just above it and the Sarawak River (#22) just below it in the modeled global ranking. It is the only river from Ivory Coast among the 50 named highest-emission outfalls.

Are the Ebrie Lagoon and Komoe River figures direct measurements?

No. The figures on this page come from global-scale modeling that blends waste statistics, population layers, hydrology, precipitation, and distance-to-coast assumptions. They are best used for relative priority and context, not as literal tonnage measured by a permanent gauge.

Sources

  1. Meijer, L.J.J. et al. (2021). "More than 1000 rivers account for 80% of global riverine plastic emissions into the ocean." Science Advances, 7(18). DOI: 10.1126/sciadv.aaz5803
  2. UNEP (2021). "From Pollution to Solution: A Global Assessment of Marine Litter and Plastic Pollution." View report

How to Cite This Page

Plastic Bank. "Ebrie Lagoon and Komoe River: Modeled Riverine Plastic Emissions." Rivers Carrying Plastic to the Ocean. https://rivers.plasticbank.com/rivers/ebrie-lagoon-komoe. Reviewed July 20, 2026.