Flood estimation is necessary to design hydraulic structures and to quantify structures failure risk. Most of the methods used for design flood estimation in Mozambique were developed in the late 1960s. Furthermore, collecting hydrological data in east Africa is a big challenge; few data are available in literature for Mozambique. Pegram (2004) proposed new approaches which are applied in this project. Annual rainfall database is analyzed, adjusted and used to assess peak discharges of 198 catchments in Mozambique. In addition, hydraulic structures (bridges and box culverts) are designed along Mueda-Negomano national road of about 170 km. Key words: Mozambique, hydrological models, sizing, box culvert, bridge.