Stilling basins are in common use when designing heading-up hydraulic structures such as
barrages, dams, weirs …etc. This research paper investigates the effect of stilling basin shapes
with different heights of end step on the characteristics of submerged hydraulic jump and the
energy dissipation downstream the radial gate. Generally, this research investigate the main
characteristics and parameters of the submerged hydraulic jump such as; the vertical velocity
distribution, the near bed velocity decay along stilling basin, and the stability of bed protection
downstream the stilling basin. In the present research paper, these characteristics will be tested in
a pool-type stilling basin with end steps downstream (DS) the radial gate of new spillway of Assuit
Barrages. The experimental program was conducted on a re-circulating flume with 1.0 m wide, 26.0
m long and 1.2 m deep, with discharges range from 40 to 190 l/s. Statistical equation was
developed to correlate the length of submerged jump with the other independent parameters.
Finally, clear matching of results from the length of jump and velocity analysis was obtained.