An alligator is pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, on the border between Paraguay and Argentina, in Boqueron, July 3, 2016. (Photo by Jorge Adorno/Reuters)

Workers use a boat to recover supplies from a flooded grain elevator May 4, 2011 in Caruthersville, Missouri. Heavy rains have left the ground saturated, rivers swollen, and has caused widespread flooding in Missouri, Illinois, Kentucky and Arkansas. (Photo by Scott Olson/Getty Images)

Spectators are swept by huge waves while watching tides of Qiantang River at a dike on August 31, 2011 in Haining, Zhejiang Province of China. More than 20 spectators were injured by strong tides as the typhoon Nanmadol approached on Wednesday. (Photo by ChinaFotoPress/Getty Images)

Fire rises from an oil tank in the port of Es Sider, in Ras Lanuf, Libya January 4, 2016. Firefighters have extinguished two fires at oil storage tanks at Libya's Ras Lanuf terminal, but blazes continue at five tanks in the nearby port of Es Sider after attacks this week by Islamic State militants, a Petroleum Facilities Guards (PFG) spokesman said on Thursday. (Photo by Reuters/Stringer)

The Mike O'Callaghan–Pat Tillman Memorial Bridge is an arch bridge in the United States that spans the Colorado River between the states of Arizona and Nevada. The bridge is located within the Lake Mead National Recreation Area approximately 30 miles (48 km) southeast of Las Vegas, Nevada, and carries U.S. Route 93 over the Colorado River.

In this photo taken Wednesday, April 30, 2014, a dragonfly sits on the nose of a Gharial, rare crocodile-like creatures, in the River Chambal near Bhopepura village in the northern Indian state of Uttar Pradesh. The narrow 250-mile stretch of the Chambal is a place of crocodiles and jackals, of river dolphins and the occasional wolf. Hundreds of species of birds, storks, geese, babblers, larks, falcons and so many more, nest along the river. Endangered birds lay small speckled eggs in tiny pits they dig in the sandbars. Gharials, rare crocodile-like creatures that look like they swaggered out of the Mesozoic Era, are commonplace here and nowhere else. (Photo by Altaf Qadri/AP Photo)

South Korean soldiers participate in a winter river crossing operation in preparation for a possible North Korean attack on February 8, 2012 in Yeoju, South Korea. The Korean peninsula is the world's last Cold War frontier as stalinist North Korea and pro-western South Korea have been technically at war since the 1950-53 conflict. (Photo by Chung Sung-Jun/Getty Images)

“El rio mas bonito del Mundo”, the most beautiful river of the world, the “River of five colors”, the “Rainbow River”, or even the “Escaped from Paradise”, are the shimmering appellations that Colombians give to Cano Cristales, a small stream located in the heart of the Macarena National Park, 150 km (93 miles) south of Bogota. Photo: A waterfall is seen at the end of the rainy season, in August, when the water level finally decreases, in the Cano Cristales RIver in the Sierra de la Macarena in Colombia. It has become covered with a bright pink endemic aquatic plant, Macarenia Clavigera. (Photo by Olivier Grunewald)