Mid-June to early July. Xiaolangdi Reservoir usually discharges water and discharges sediment from mid-June to early July. By then, the Xiaolangdi water conservancy project will officially release water and start the flood dispatching mode. Huge waves and huge waterfalls will present a magnificent landscape of "how the water of the Yellow River leaves the sky and enters the sea, never to return". Xiaolangdi needs a lot of water to regulate sediment and release water, that is, to wash away the sediment deposited in the reservoir during the flood season. Such a big project can be realized, which is inseparable from the design function of Xiaolangdi.