A master's thesis at wasit University's Faculty of Engineering discussed a pilot study of the hydraulic properties of the co-flow over a wide-top roar with a slot. This work included examining the impact of changing waste dimensions on runoff properties and energy dispersion to protect origin from excess energy that may cause erosion of the bottom of the canal. The results showed that the higher the water above the roar, the longer and less the roar, the higher the roar. Furthermore, an increase in the value of energy dispersion was recorded in the case of openings, the highest dispersion of energy recorded when using the circular aperture and then came the square opening and then the rectangle. The first method relied on the principle of remote analysis and incomplete self-similarity, the second method is traditional, including the calculation of discharge plants. The two methods were evaluated. The first method was the most accurate. Numerical simulation results showed compatibility with experimental work