Laboratory Investigation of Stilling Basin Slope Effect on Bed Scour at Downstream of Stepped Spillway: Physical Modeling of Javeh RCC Dam Elnaz Eghlidi 1 & Gholam-Abbas Barani 2 & Kourosh Qaderi 1 Received: 1 May 2019 /Accepted: 21 October 2019/ # Springer Nature B.V. 2019 Abstract Stepped spillway and stilling basin are one of the most important energy dissipation structures. Eventhough, most of energy dissipated by these structures, but in skimming flow, the upstream flow motion is nonaerated and the residual energy capable to destroyed structures during floods. In this study, effect of stilling basin slope on bed scour, downstream of Javeh dam was investigating. Experiments performed in hydraulic structures laboratory of the University of Kerman with six different discharges (5, 7, 13, 17, 25 and 30 l/s.m) and five various stilling basin slope (0.02, 0.01, 0, -0.01 and - 0.02). The parameters such as maximum scour depth (d s ), flow velocity (in three point), water depth on upstream and downstream of stepped spillway and stilling basin, the distance of the maximum scour depth to sill (L s ) and the gheometery of scour hole measured. Result shown that when stilling basin slopes was 0.02, the average of maximum relative scour depth, 47% Increased and in -0.02, 52.2% Decreased. In addition, the distance of maximum scour depth until stilling basin increased by increasing and decreased by decreasing the stilling basin slope. Keywords Stilling basin . The energy dissipation structures . The maximum depth of scour . Scour hole Water Resources Management https://doi.org/10.1007/s11269-019-02395-5 * Elnaz Eghlidi elnazeghlidi70@gmail.com Gholam-Abbas Barani gab@uk.ac.ir Kourosh Qaderi kouroshqaderi@uk.ac.ir 1 Department of Water Engineering, Faculty of Agriculture, Shahid Bahonar university of Kerman(UK), Shiraz- Mollasadra Street, Hedayat Street, Kerman 191, Iran 2 Department of Hydraulic Engineering, Shahid Bahonar university of Kerman (UK), Kerman- Shahid Bahonar University, Kerman, Iran