Аннотация:Оne of the main task for engineer during design of hydraulic engineering structures is an accurate calculation of weir profiles in open streams. Modern technologies make it possible to obtain building materials that allow realization of the given shapes of the surface of dam structures. To increase the reliability of building structures elements of spillway
vacuum-free dams, there is a need to improve methods of calculating configuration of the drainage surface in the area where it meets the apron.