The Sanmenxia Dam on the Yellow River was the first of its kind.  It was constructed to prevent midstream sediments from flushing downwards, but it incurred problems over the years. Unlike many other river dams in the world, the dam facilities on the Yellow River had to consider thick, heavy sediment. Passed through the Loess Plateau, the river carried mud and sand downstream. Sediment deposits had long been an obstacle, but the situation improved.