The Stream Restoration Program utilizes hydrologic and hydraulic models for estimating runoff quantities, rates and the hydraulic forces impacting a reach of stream. These analyses provide parameters for use in stable channel design. For projects within an existing floodplain, generally the existing FEMA hydrology and hydraulic models are used. For smaller projects models are developed for each specific project. Common models used are:
Hydrology: HEC-1 TR20 FFA
Hydraulics: HEC-2 HECRAS (HECGEORAS) WSPRO Manning’s Equation
Results from the H&H analyses are used to estimate channel boundary shear stresses and sediment transport capacities, which allow for prediction of future short- and long-term channel erosion and provides data for design of channel stabilization measures.