2026 River Cup
Welcome to the 2026 River Cup! Vote for your favorites here to help us determine Earth's most remarkable river system!
Round 1: Water Quality Threats
Matchup 13: Niger vs Citarum
Niger River
The Niger River is about 2,600 miles long and flows through West Africa to the Atlantic Ocean.
Citarum River
The Citarum is the third-longest river in Java, the largest island in Indonesia. It has a tropical monsoon climate, with an average annual temperature of 26°C.
Cast your vote!
Matchup 14: Cape Fear vs Rio Tinto
Cape Fear River
Flowing into the Atlantic Ocean, the Cape Fear River is a 191 mile long blackwater river in North Carolina, USA
Rio Tinto
The 62-mile-long Rio Tinto has naturally acidic, red-colored water rich in iron and sulfate. It supports acid-loving microorganisms.
Cast your vote!
Matchup 15: Llobregat vs Susquehanna
Llobregat River
The Llobregat River (or "El Llobregat") originates at an elevation of 4,131 ft and flows for 110 miles through Spain before draining into the Mediterranean south of Barcelona
Susquehanna River
At 444 miles long, this river is the largest on the East Coast of the United States, and flows into Chesapeake Bay, the largest estuary in the U.S.
Cast your vote!
Matchup 16: Fly vs Matanza-Riachuelo
Fly River
Fly River in Papau New Guinea is over 660 miles long and is part of the the longest river system of any island on earth.
Riachuelo River
Although Matanza–Riachuelo River is only 40 miles (64km) long, its basin hosts 10% of Argentina's population.
Cast your vote!
RIVER CUP 2026 CURRENT BRACKET
YOUR CATCHMENT CUP 2025 WINNER: ONCA CATCHMENT!
YOUR CATCHMENT CUP 2025 WINNER: ONCA CATCHMENT!
Congratulations to our 2024 Earth's Most Remarkable River:
the Gila!
Congratulations to our 2023 World's Most Remarkable River:
