Sediment models are often more sensitive to hydraulic modeling choices that fixed bed models. Adding sediment to a hydraulic model that runs and generates reasonable results often exposes model problems hidden by the robustness of the hydraulic equations or approximations that were sufficient for hydraulic analysis but not for sediment modeling. Sediment modelers should consult the 2D hydraulics manuals to help them construct an excellent, calibrated hydraulic model before they move on to a sediment simulation.  However, this section summarizes several of the hydraulic modeling best practices (and most common mistakes) that will propagate into strong or poor sediment results.