The proposed design of the water level autoregulator with flexible working bodies for the channels of the parabolic section of the irrigation system is made in the form of a gate, which is a container formed by a rigid bottom, a pressure part made of flexible rubberized meliorative fabric, a rigid frame part of the spillway with a non-vacuum type profile covered with flexible meliorative fabric, and soft side elements also made of flexible rubberized meliorative fabric, which are a continuation of the pressure and spillway parts. Regulation of the water level in front of the autoregulator is carried out using a water level regulator. To determine the flow capacity of the gate of the proposed design of the water level autoregulator, a theoretical formula was derived, and experimental studies were carried out to determine the values of the flow coefficient included in this formula. The study was carried out on an experimental installation by the physical modeling method of the model and nature. As a result of the mathematical processing of the results of studies of the shutter model, an empirical formula was obtained for determining the shutter flow rate depending on the ratio of the iridescent water layer's thickness to the shutter's height. At the same time, the difference between the obtained values of the flow coefficients according to this formula and the results of experimental studies was +4...5 percent. This automatic water level regulator performs the function of a partition structure, does not require high costs, and can be portable and stationary; it is not metal-intensive, lightweight, transportable, combines the functions of stabilizing the required water level in the channel, dumping excess water, fin and debris, provides the necessary water enters the outlet openings of the channel.