fivemile creek FEMA letter of map revision (LOMR)
PROJECT TYPE
Waterway & Floodplain Management
CLIENT
City of Meridian
LOCATION
Meridian, ID
project description
Under our Hydraulic Engineering term agreement with the City of Meridian, WCG prepared a letter of map revision (LOMR) to revise the FEMA floodplain and floodway for Fivemile Creek in the vicinity of E Franklin Street and S Locust Grove Street. Previous FEMA mapping showed the floodway out of alignment with the stream channel. Additional development within the floodplain had occurred since the effective model including a stream enhancement project and subdivision development within the flood fringe.
WCG duplicated and corrected the effective model and created a revised conditions model in HEC-RAS of the 10%, 2%, 1%, and 0.2% flood intervals. We also completed a floodway encroachment analysis.
The new flood mapping corrects the floodway misalignment and depicts the base flood inundation at a higher level of detail using recent LiDAR topography.
key services list:
Hydraulic modeling and analysis
Topographic updates using LiDAR
Floodplain inundation mapping
FEMA application forms
Hydraulic memorandum describing methodology