Data gathered by coastal geologists conflict with this engineering model. Bottom sediments are moved landward in response to overhead waves. Oceanic storms have little trouble moving deposits that are deeply submerged on the continental margins. In other words, geologists have demonstrated that the entire beach profile is active. There is no inactive sedimentary zone as seen in the engineering model.
Engineers are unable to supply actual data to support the river of sand model.
The theory is based on the observation that at certain nearshore depths, bottom elevation remains fairly constant. One way to view the engineering model is to consider the movement of sand on riverbeds. Bottom elevations could be measured at a point on the Mississippi River, for example. Over time, as the bottom contour changed little, one may conclude that little sediment moves along the river bed, an incorrect assumption. Another view of the river of sand theory is afforded by a look at the Atlantic shoreline in Florida.