Application of Two-Dimensional Hydraulic Simulations and Habitat Modeling for the Assessment of Channel Restoration Designs

Evaluation of the potential cost-benefits associated with proposed stream channel restoration designs were evaluated using two-dimensional hydraulic and habitat modeling approaches. Channel topographies in three test sections were derived by combining digital elevation data generated from low elevation high resolution aerial photogrammetry and channel survey data. The combined digital terrain model was used to develop a hydrodynamic computational mesh for use in two-dimensional hydraulic simulations of the flow field. Habitat computations for target species and life stages were accomplished by integrating substrate and cover mapping in GIS with the hydraulic properties to compute the amount and quality of available habitat under existing stream conditions. Proposed channel restoration designs were evaluated by modification of the underlying computational meshes in each study reach and modification of the substrate and cover values based on reference hydraulic conditions. Available habitat quantity and quality were computed for target species and life stages based on the expected changes in channel topography, hydraulics, and proportional contribution of specific meso-habitat types within the study reaches