Until now, hydraulic research of stepped spillways has focused on characterizing aspects as: the different types of flow that occur on the dam, the air inception processes, the potential negative effects associated to the risk of cavitation, the energy dissipation produced by the steps, or the discharge capacity of the spillway. These investigations, however, have focused on stepped spillways with sidewalls, which impose a continuous width along the dam. This paper shows the first results of the research project ALIVESCA, the project aims to analyze the behavior of stepped spillways without sidewalls and establish criteria for new trends of design in this kind of spillways. The absence of the sidewalls will reduce costs and risks in the project execution since it does not require the construction of concrete lateral walls that usually require major works. ALIVESCA has raised from the initiative between the company Dragados S.A. and the FLUMEN Institute of the Polytechnical University of Catalonia, as a Collaborative Applied Research project, with the aim of increasing the capacity to develop new trends in the stepped spillway design. The project also counts with the collaboration of the Centre for Hydrographic Studies of CEDEX.