. . "The River Kasai is 1,338 miles (2,153 km) long. It has an average discharge of 10,000 m\u00B3/s and a drainage area of 880,200 km\u00B2. It flows into the Congo. The countries within its drainage basin are: Angola, Democratic Republic of the Congo"@en . "How long is the River Kasai"@en . "The River Kasai is 1,338 miles (2,153 km) long. It has an average discharge of 10,000 m\u00B3/s and a drainage area of 880,200 km\u00B2. It flows into the Congo. The countries within its drainage basin are: Angola, Democratic Republic of the Congo"@en .