The mission of the OHD hydraulics group is to develop and evaluate hydraulic modeling techniques suitable for use in operational river forecasting, assist the OHD Hydrologic Software Engineering Branch in transitioning these techniques into operational software, and provide scientific support for implementation at field offices. We strive to provide forecasters at National Weather Service River Forecast Centers (RFCs) with tools to improve their river forecasts. RFCs serve a wide variety of users by producing routine forecasts of both water flows and water levels over a range of time scales. To create water forecasts, RFCs collect hydrometeorological observations and forecasts and use this information to force hydrologic models. RFCs then use hydraulic models to translate forecasted flows from hydrologic models into water levels. NWS operational hydraulic models range in complexity from simple rating curves to one-dimensional dynamic wave modeling. Flood forecast maps based on hydraulic models are also available in some locations. Hydraulic models must account for both natural landscape features (e.g. wide floodplains) and man-made structures such as bridges, dams, levees, and other structures. We are actively investigating the potential benefits and feasibility of using more complex two-dimensional (or even three-dimensional) models to improve our forecasts. At the same time, we strive to support expansion and improvements to implementations of existing models.