A hydrologic model was developed as part of the Southeast Regional Assessment Project using the Precipitation Runoff Modeling System (PRMS), a deterministic, distributed-parameter, process-based system that simulates the effects of precipitation, temperature, and land use on basin hydrology. Streamflow and other components of the hydrologic cycle simulated by PRMS were used to inform other types of simulations such as water-temperature, hydrodynamic, and ecosystem-dynamics simulations.