The design of earth dams has sometimes been subjected to finite element flow or deformation numerical models. Such numerical models can improve designs and allow for the relatively inexpensive identification of potential flaws in designs prior to construction. A difficulty that has been traditionally encountered in practice is that many earth dams are 3-D in nature due to the valley in which they are typically placed. A 2-D numerical model is often inadequate or unable to represent the flow or deformations encountered close to the intersection of the earth dams with the valley walls. Another complication is that there are significant pinchout issues with the intersection of the earth dam with the valley. Many earth dams may be made up of complex low-conductivity cores or drainage sections which ultimately result in fairly complex and highly 3- D geometries with many pinch-out zones. Such geometries are extremely difficult to model with existing software tools. This paper presents a methodology based on i) integration of surface meshing methods and ii) the transference of surface meshes to volume meshes for the quick creation of 3-D finite element numerical models for the purpose of ultimately creating a 3-D flow or stress/deformation numerical model of an earth dam. The methodology allows geotechnical engineers to work off of readily available cross-sectional designs and allows for the accommodation of pinch-out zones in the mesh as the earth dam intersects the valley walls. The paper also presents a real-world case study proving the concept. An earth dam with a core is modelled based on actual site data rather than an idealized conceptual model. The methodology allows the expansion of the type of numerical models which can be created and solved in industry and has application in the areas of levees and tailings dams.