Abstract: To explore long-term de-siltation for the Lower Yellow River (LYR), the authors proposed to redirect the planned Yumenkou project’s objective to sediment release after sort of the LYR harmful coarse sediment (CS), making use the mechanism of graded sediment sorting in gorge reservoirs along with successive dredging and CS refining. The effect was assessed with a new measure, instead of the widely used total sediment for engineering de-siltation, indicating that the proposed scheme could be effective in sort-diverting the CS, able to provide controlled stable releasing condition of the CS to the planned storage and farther to the low-lying plains under the Sanmenxia backwater and it would also be possible to remove the diameter＞0.1mm CS as construction aggregate in the future. For a scenario of 1.24 Gt/a sediment to Sanmenxia, a continuous dredging of about 60Mt/a from the dam front can depress the equilibrium slopes of downstream fluvial sedimentation by 10%, that would be sizable in preserving final storage of the flood-control reservoirs, to lower the LYR uprising potential and to curtail the sediment flushing water.