A waterfall is a geological feature where a river or stream flows over a vertical drop or a series of steep descents. These natural spectacles often form where water erodes softer rock beneath a more resistant layer. Defining the world’s absolute “largest” waterfall is complicated because the term must be broken down into three distinct, measurable characteristics to capture the true scale of these giants.
How Waterfalls Are Measured
Geographers and hydrologists classify the world’s largest waterfalls using three separate metrics. The first is the total vertical drop, which quantifies a waterfall’s height from the crest to where it collects below. This metric is further refined by noting the longest single, uninterrupted plunge, as many tall falls consist of multiple tiers. The second measurement is the horizontal span, or the width of the water curtain along its crest line. The third metric assesses the average volume of flow, calculated as the amount of water moving over the falls per second, typically expressed in cubic meters per second.
The Highest Vertical Drops
Angel Falls (Kerepakupai Merú) in Venezuela’s Canaima National Park holds the title of the world’s tallest waterfall. It plunges from the Auyán-tepui table mountain, a massive sandstone plateau, with a total recorded height of 979 meters (3,212 feet). The longest single, uninterrupted drop measures 807 meters (2,648 feet). The force of the fall is so extreme that much of the water turns into a fine mist before it reaches the ground below. Tugela Falls in South Africa’s Drakensberg mountains presents the only real challenge, with an officially measured total drop of 948 meters (3,110 feet) spread across five distinct tiers. Recent measurements suggest a possible total height of 983 meters (3,225 feet), which would make it the tallest overall drop, though it lacks the single plunge of Angel Falls.
The Longest Water Curtains
Focusing on the horizontal dimension reveals waterfalls defined by the length of the water’s crest line. Victoria Falls (Mosi-oa-Tunya, meaning “The Smoke That Thunders”) on the Zambezi River between Zambia and Zimbabwe is recognized as the world’s largest single sheet of falling water. The falls span 1,708 meters (5,604 feet) wide and 108 meters (354 feet) high, creating a continuous curtain. The Zambezi River plummets into a narrow chasm, causing a massive spray visible for kilometers. Iguazu Falls, located on the border of Argentina and Brazil, stretches 2.7 kilometers (1.7 miles) along its edge. This system is segmented by numerous islands, creating around 275 individual falls that vary in height between 60 and 82 meters.
The Greatest Volume of Flow
The most powerful waterfalls are defined by their flow rate, which is the volume of water they discharge per second. Boyoma Falls (formerly Stanley Falls) on the Lualaba River in the Democratic Republic of the Congo holds the record for the largest volume of annual flow rate. This system is a series of seven cataracts and rapids extending over 100 kilometers, with a modest total drop of 61 meters (200 feet). Boyoma Falls discharges an average annual flow rate estimated at 17,000 cubic meters per second (600,000 cubic feet per second). Khone Falls on the Mekong River in Laos is another high-volume cascade system, spanning 10,783 meters (6.7 miles) wide with an average discharge of about 11,000 cubic meters per second.