As part of ESP's role on the Watershed Concepts team for the NC Floodplain Mapping Program, ESP was responsible for the development of five flood warning map libraries to support the State of North Carolina Flood Inundation Mapping and Alert Network (FIMAN). The Map libraries will be used by State and local emergency managers to graphically display current and projected flood inundation areas and depths for vulnerable locations throughout the State.
Scope of Services
ESP's project scope included the following:
The development of a detailed hydraulic model for each site. These hydraulic models extended approximate 3000' upstream and downstream of the map library site. The models contained field surveys for the hydraulic structure crossings (culverts, bridges) and surveyed stream channel cross sections.
Detailed Manning's n-value layers using field survey information and aerial photographs
The hydraulic models were calibrated to any USGS gage rating curves or any effective or preliminary FEMA Flood Insurance Study as applicable.
Rating curves were developed for each site using a range of discharge values.
Hydraulic models were iteratively ran to achieve flood events for every half foot (0.5 ft) at the proposed gage location (typically the upstream side of the structure)
Flood boundaries were mapped for the entire studied reach for each half foot flood profile. The mapped boundaries are the basis for the map libraries
Depth rasters (GRIDs) were created showing average flood depths at locations throughout the floodplain.
back
Water Resources, Floodplain Mapping
