The nature and distribution of soil particles and pores plays a strong role in determining the soil hydraulic properties (specifically the soil water retention curve and the relative hydraulic conductivity curve) that govern water movement. A new mathematical model for these hydraulic properties was developed by conceptualizing the soil as a random assemblage of soil particles represented by randomly sized overlapping spheres (fully penetrable spheres). The spatial arrangement of the spheres was assumed to follow a homogeneous Poisson process. A stochastic analysis was utilized to obtain analytical expressions for soil water retention curves and relative conductivity at varying water contents. Unlike the existing models of soil hydraulic properties, this new model incorporates soil porosity in estimating model parameters. Furthermore, because of this conceptualization, we are able to determine the types of soils for which the model is appropriate. A quantitative evaluation of the new model was performed by examining data on hydraulic properties for several soils. In addition, quantitative and qualitative comparisons were made with currently used expressions (such as the van Genuchten model, Brooks-Corey relationship, and Kosugi model) for the same data sets. Results show that the new model provides reasonable fits with the observed water retention curve and good predictions of the hydraulic conductivity, particularly for soils exhibiting a distinct air entry pressure.