Аннотация:On the basis of a physical model linking the formation of ridges at the bottom of rivers with the action of stationary waves with fixed crests on the water surface, it is proposed the hypothesis of the formation of Baer hillocks in the Volga delta with peak water flow during a sudden decrease in the level of the Caspian Sea. The proposed hypothesis makes it possible to describe all the features of the Baer ridges: in areas 10 km long, the ridge tops that exceed the middle line are located at the same distance from each other, the surface oscillations below this line do not have a regular component. An estimate of the flow Froude numbers was obtained for which the Baer ridges were formed:0.68 < Fr < 0.73.