A culvert is a hydraulic structure constructed to increase the water carrying capacity away from highway and buildings in the environment. Culverts have received less attention over the years because they are not highly visible, even if they have sufficient performance. Culverts offer much smaller investment options compared with bridges and in many cases they have replaced small bridges. Culverts are also less hazardous in the case of failure. This study brings together results about several variables of culverts including optimum dimensions, shapes, materials and inlet configurations. During culvert design, hydraulic testing was required for sizing of structures, where risk analysis calculation has been performed regarding the probability of inadequate capacity of culvert design to pass floods. The failure probability is estimated using the advanced first order second moment (AFOSM) method. Therefore, the methodology ensures the design of the hydraulic structure fulfills the required role, while minimizing its future effects in the environment.