The Rio Tinto river in Spain crosses an ancient mining site which makes the water turn a variety of bright colours. Copper, silver and gold are mined here, as well as iron, which turns the water red. An ochre mix is responsible for the yellow tint of the rest of the river. (Photo by Olivier Jarry-Lancombe/Solent News)

A fireman pulls a woman and her dog to shore, by a row of houseboats on the river Seine in Paris France, Wednesday June 1, 2016. The Seine River has overflowed embankments in Paris as floods hit or threaten cities and towns around France. (Photo by Jerome Delay/AP Photo)

A Sadhu or a Hindu holy man sits on the banks before taking a holy dip at Sangam, the confluence of the Ganges and Yamuna rivers with the mythical, invisible Saraswati river, during the “Maha Kumbh Mela”, or the Great Pitcher Festival, in Prayagraj, India, on January 13, 2025. (Photo by Adnan Abidi/Reuters)

A dog swims as a resident navigates his boat in a neighbourhood flooded by the Purus river, which continues to rise from days of heavy rainfall in the region, in Boca do Acre, Amazonas state March 14, 2015. According the state civil defense, more than 20,000 people have been left homeless along the Purus river, where incessant rains have flooded the area and caused the river to burst their banks. (Photo by Bruno Kelly/Reuters)

Tim Anderson final balanced rock stack in the Llano River. Tim Anderson, rock balancing “pro” from Pennsylvania, carefully worked to balance his stack on a dry spot in the Llano river Saturday March 12, 2016. He was an honored guest of the festival and enjoyed visiting Texas so he came for another year. The river was higher this year because of the rains so the balancers could not get to the better rock that were available last year. (Photo by Nell Carroll/American-Statesman)

“Winter shapes, Moscow river”. Moscow river at this part is never covered by ice. When the temperature is very low it's possible to see a strong fog. Morning light and pipes of the oli factory creates a fantastic landscape. Photo location: Moscow, Russia. (Photo and caption by Sergey Rumyantsev/National Geographic Photo Contest)

Rick Sorenson, owner of the Rio Ramaza Marina, wades in the Sacramento River after securing an old paddlewheel boat on his property as the river makes its way up the levee on Garden Highway in Sacramento, Calif., Monday, January 9, 2017. (Photo by Hector Amezcua/The Sacramento Bee via AP Photo)