Waterfall dries up after mystery hole in the ground envelopes liquid
The San Rafael waterfall in Ecuador has run dry, local officials have traced the cause to a large sinkhole that opened beneath the river that once fed the falls.
Located in Cayambe Coca Park, part of the Ecuadorian Amazon near the border with Colombia, the falls ranked as the tallest in the country at more than 500 feet.
The government has restricted access to the site of the falls and surrounding area as a team investigates what caused the sinkhole.
Some have pointed to a hydroelectric plant 12 miles upstream as a possible cause.
‘A waterfall that has been there for thousands of years does not collapse, coincidentally, a few years after opening a hydroelectric project,’ Emilio Cobo, coordinator at the South America Water Program with the International Union for the Conservation of Nature, told Mongabay.
‘These are processes that are in scientific papers and there is sufficient evidence that a dam can cause effects of this type on a river.’
The plant, which was built by the Chinese company SinoHydro and opened in 2016, isn’t directly on the river, but it has a diversion reservoir that’s designed to remove between 90 and 100 percent of the sediment from the river before its waters reach the plant.
Sediment acts as a protective layer in riverbeds, helping to insulate the ground below from water erosion.
Without a steady flow of new sediment from upstream, the older sediment is eventually washed away, leaving more of the riverbed susceptible to erosion, a condition researchers describe as ‘hungry waters.’
Whatever the cause, researchers agree the sinkhole will radically reshape the region as the once unitary river has now been split into three smaller streams, each of which have formed their own small waterfalls along the jungle ridge.
These newer and smaller waterfalls, will bring added risk of landslides and potentially threaten the well being of fish and other invertebrates that had been a part of the river’s ecosystem for years.