Daivões dam spillway: a novel solution for the stilling basin

Abstract

The Upper Tâmega Hydroelectric Project is located in the Tâmega River, a tributary of Douro River, and includes, among other elements, the construction of three dams: Alto Tâmega, Daivões and Gouvães. Daivões Dam is a concrete arch gravity structure, 77 m high above foundation, with a gated controlled spillway, located in the center of the dam, and followed by stilling basin controlled by a tall end weir to force the hydraulic jump in a shorter distance. The hydraulic performance of the proposed spillway stilling basin was tested and optimized on a physical model at 1:50 scale. The paper presents the results of the physical models study and the final unconventional solution adopted for the spillway stilling basin.