San Rafael Falls

San Rafael Falls
San Rafael Falls in 2012
Location	Sucumbíos and Napo, Ecuador
Coordinates	0°06′13″S 77°34′53″W / 0.1037°S 77.5813°W / -0.1037; -77.5813
Type	Tiered plunges (until 2015) Plunge (2015–2020)
Total height	131 m (430 ft) (until 2020)[1]
Number of drops	2 (until 2015) 1 (2015–2020)
Total width	30 m (98 ft) (until 2020)[1]
Average width	23 m (75 ft) (until 2020)[1]
Run	46 m (151 ft) (until 2020)[1]
Watercourse	Coca River
Average flow rate	293 m3/s (10,300 cu ft/s)[2]

San Rafael Falls (Spanish: Salto de San Rafael) was a waterfall on the Coca River in Sucumbíos and Napo, Ecuador.^[3] Standing 131 metres (430 ft) high,^[1] it was the tallest and most powerful waterfall in Ecuador and a popular tourist attraction. The falls were located at the eastern boundary of Cayambe Coca National Park, in the eastern Andean foothills about 170 kilometres (110 mi) to the east of Quito.

On February 2, 2020, the falls collapsed into a massive sinkhole behind the layer of hard volcanic rock that formed its lip, creating a large natural bridge spanning the Coca River.^[2] The natural bridge also collapsed about one year later, leaving an open ravine at the former site of the falls. During its brief existence, the natural bridge may have been the longest in the world, exceeding China's Xianren Bridge.^[4] The waterfall itself retreated upstream as a result of rapid headward erosion and disappeared within a few months as the river carved a new, more gradually descending channel.^[2]

The collapse of the falls has significantly altered the Coca River, with a deep new canyon appearing upstream of the former falls, and large volumes of sediment depositing downstream. Upstream erosion destroyed several bridges and oil pipelines, and as of 2023 threatens to undermine the Coca Codo Sinclair Dam, which was built upstream of the falls in 2016. Increased erosion as a result of the dam trapping sediment is thought by some researchers to have accelerated the collapse of the waterfall, although the phenomenon would likely have happened eventually due to the natural erosive force of the river.