This paper highlights the finite element hydrodynamic and transport modeling developments being conducted by the U.S. Army Engineer Waterways Experiment Station (WES) and its partnering organizations. The WES developments in support of surface water, groundwater, and watershed management are presented. A particular facet of these developments, the creation of integrated, comprehensive modeling systems which greatly increase the productive use of WES hydroenvironmental models, is discussed. Future development directions, including the use of scalable high performance computing resources, are also provided.