The Yellow River, north-central China, and comparative rivers of the western United States, the Rio Grande and the Colorado River, derive much of their flows from melting snow at high elevations, but derive most of their se diment loads from semiarid central parts of the basins. The three rivers are regulated by larg e reservoirs that store water and sediment, causing downstream channel scour and, farthe r downstream, flood hazard owing to re- deposition of sediment. Potential approaches to reducing continui ng bed aggradation and increasing flood hazard along the lower Yellow Ri ver include flow augmentation, retirement of irrigation that decreases flows and increas es erosion, and re-routing of the middle Yellow River to bypass large sediment i nputs of the Loess Plateau.