“Flocculation is crucial for the structure and flowability of sediment in silty estuaries and port waterways, but its quantitative impact on the critical start-up of floating sediment is not yet clear. Experts conducted a constant water flow tank start-up test to quantitatively analyze the influence of factors such as median particle size D ₅₀, wet density, clay content, and yield stress τ y on the critical start-up law of flocculated floating mud. They constructed a critical start-up Shield number criterion for flocculated floating mud based on yield stress, providing parameter tools and mechanical basis for predicting the evolution of floating mud thickness in silty estuaries and port waterways, evaluating dredging and siltation, and discriminating navigation conditions.”