Reservoir Regulation has Brought a Classic River‐Dominated Delta Under Human Control

Abstract Damming of wild rivers has trapped vast quantities of sediment that would otherwise nourish deltas, causing severe sediment deficits and accelerating delta erosion worldwide. The Yellow River Delta (YRD), once prograding seaward at ∼10 km 2 /yr, began retreating at −5.6 km 2 /yr following completion of the Xiaolangdi Reservoir. Implementation of the Water and Sediment Regulation Scheme (WSRS)—a reservoir flushing program—fundamentally reversed this trend. By mobilizing trapped sediment and enhancing downstream channel scouring, the WSRS increased sediment delivery to the sea from 17.6 Mt/yr before its initiation to 178.5 Mt/yr during operation years. This renewed sediment flux restored delta growth, producing subaerial expansion of 6–7 km 2 /yr and significant subaqueous deposition near the estuary. These results demonstrate that the YRD has entered a new phase of evolution under active human management and highlight that sediment trapped behind dams can become a potentially important source for restoring sediment‐starved deltas worldwide.