EFDC1D – A One Dimensional Hydrodynamic and Sediment Transport Model for River and Stream Networks, Model Theory and Users Guide

been subjected to the Agency’s peer and administrative review and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. This technical report describes the new one-dimensional (1D) hydrodynamic and sediment transport model EFDC1D. This model can be applied to stream networks. The model code and two sample data sets are included on the distribution CD. EFDC1D can simulate bi-directional unsteady flows and has the ability to accommodate unsteady inflows and outflows associated with upstream inflows, lateral inflows and withdrawals, groundwater-surface water interaction, evaporation and direct rainfall. The model also includes representation of hydraulic structures such as dams and culverts. For sediment transport, the model includes settling, deposition and resuspension of multiple size classes of cohesive and noncohesive sediments. The bed is represented by multiple layers of mixed sediment classes. A bed consolidation model is implemented to predict time variations of bed depth, void ratio, bulk density and shear strength. The sediment bed representation is dynamically coupled to the cross-sectional area representation to account for area changes due to deposition and resuspension