PHOTOS: Spectacular Yellow River Xiaolangdi Waterfall-Watching Festival

The Yellow River Xiaolangdi Waterfall-Watching Festival has become an tourist attraction in Luoyang, central China's Henan Province, as people throng to watch what is surely the world's most spectacular process for removing sediment from a river.

The sediment builds up and slows the water flow in the lower reaches of the waterway.

The Xiaolangdi Dam regulates water and silt flow annually.

The festival lasts from June 30 to July 5 this year.

When the Xiaolangdi reservoir dam takes off the brakes and discharges floodwater, a 70-meter-long waterfall rushes down the aptly-named Yellow River.

The temperature of Xiaolangdi scenic spot is 4 to 5 degrees lower than the urban district of Luoyan.

It's even cooler at the water outlet too, 10 degrees lower than city temperatures.

The Dam is a multifunction project designed for flood control, ice control, dredging, industrial and municipal water supply, and hydroelectric power generation.

Located 40 km north of the ancient city of Luoyang, the dam is the largest on the Yellow River, and second only in size in China to the Three Gorges Dam on the Yangtze River.

Since 2002, 14 such operations have been conducted at the reservoir.