Effects of flow depth, ions, and salinity on the evolution of suspended sediment concentration (SSC) are presented. Experiments are conducted in an annular flume using three different sediments (Rhine mud, alumina, and silica) in ionic and saline water. Observations show that at a constant bed shear stress (τ) in ionic water, the SSC of all sediments decreases because of an increase in the flow depth. At a constant the SSC increased with an increase in τ When H and τ remained constant, alumina and silica particles quickly flocculated and attained a lower equilibrium concentration (C eq)in ionic water than in saline water. Similarly, the flocculation process of Rhine mud is faster in ionic water, but the C eq in ionic water is higher than that of saline water. For all the sediments tested, the time to reach C eq is greater in saline water than in ionic water. In saline water, the evolution of SSC of Rhine mud is in between that of alumina and silica. © 2012 American Society of Civil Engineers.