We present strategies to perform large-scale simulation of saturated groundwater flow using mixed finite element methods. The greatest limitation of these methods is their memory requirements. To overcome the memory limitations of the mixed methods, we use a domain decomposition strategy. We also present a multigrid acceleration for the domain decomposition. For sufficiently small problems, the conventional mixed method is more computationally efficient than the domain decomposition approach. However, the domain decomposition method allows one to simulate larger problems than is possible with the conventional mixed method. ¿ American Geophysical Union 1993