The article presents the results of research on the substantiation of giving a stable shape of cross-section to the channels of hydro-reclamation systems of southern Kazakhstan. The calculations on the stability of irrigation channel slopes were made, as well as their design features and practical substantiation of stable profiles were presented. The shapes of stable slope were determined using of actual values of geotechnical parameters of slope soils. The results showed that the slope profile takes a stable shape during the channel operation, close to the parabolic.