ZHENGZHOU, June 26 (Xinhua) -- A water and sediment regulating operation has been carried out at Xiaolangdi Reservoir on the Yellow River since June 23 in central China's Henan Province. The ongoing operation works by discharging water from the reservoir to clear up the sediment in the Yellow River. This year, the operation will be jointly conducted in Xiaolangdi Reservior, Sanmenxia Reservior and Wanjiazhai Reservoir, an effort to make speeding currents carry tons of sand into the sea. The operation will last for 17 days.