Trancoso is a small city in the state of Zacatecas, Mexico that has experienced flooding problems along the stream Barrio del Refugio. In recent years, the flooding, which starts at the road towards the western edge of town, has flooded nearby buildings to a height of over 5 ft. The residents of the area say the stream floods two to three times per year. Two upstream sub-basins contribute to this stream. Each year, runoff from the two upstream sub-basins results in flooding, mainly in the part of the town that is downstream from a major road. The purpose of this project was to perform a watershed hydrologic and hydraulic analysis that included the effects of the detention basin and the road. In addition, we wanted to provide an engineering solution to help mitigate the flooding.