LWI Region 5 Mermentau - West Bayou Grand Marais at River Station 9 HEC-RAS Simulation: Historic Event Scaled to 100-Year Design Storm
This simulation represents the 100-year design storm event for the KCDA area. The event is based on the August 2016 historical tropical storm scaled to the 100-year 12-hour design storm precipitation volume. The storm critical duration was determined by modeling the gridded precipitation over the KCDA area and identifying the peak flow leaving the KCDA area for a variety of storm lengths. To match the design storm volume, the August 2016 historical storm was configured with a 1.15 scale factor for KCDA ME_WBGM_009_UG. The model simulation was created in HEC-RAS Version 6.5. This represents the 2017 to 2019 existing conditions Mermentau geometry with calibration regions configured for validation as an average of calibration events. The simulation includes: a constant boundary inflow hydrograph for the Mermentau River based the 50th percentile flow of 500 cfs; design storm precipitation based on scaling of the August 2016 storm event; a constant mean high high water variable downstream tidal boundary condition; a constant downstream stage hydrograph of constant 50th percentile of 2.49 ft (NAVD88) at the Gulf Intracoastal Water Way derived from USACE Gage #76800, and infiltration over the watershed. The initial simulation time step is 5 seconds with the control by courant condition option enabled, allowing HEC-RAS to adjust the timestep as condition warrant during the simulation. This simulation is most applicable from river station 9 (ungaged) of West Bayou Grand Marais to the upper watershed for West Bayou Grand Marais.
Model Software Version
HEC-RAS version 6.5Model Application
LWI Region 5 Mermentau - West Bayou Grand Marais at River Station 9 HEC-RAS ModelSimulation Type
SCENARIOInput Files
| Title | Description | Location |
|---|---|---|
| Boundary Condition File | Stores boundary condition information for simulation | /ME_WBGM_009_UG/Mermentau_DS.b05 |
| Initial Conditions File | Stores all configured hydraulic initial conditions for running simulation | /ME_WBGM_009_UG/Mermentau_DS.ic.o05 |
| Unsteady Flow File | Stores user-defined flow options, initial conditions and hydrographs are stored | /ME_WBGM_009_UG/Mermentau_DS.u05 |
| Plan File | Contains a list of associated input files and all simulation options | /ME_WBGM_009_UG/Mermentau_DS.p05 |
Output files
| Title | Description | Location |
|---|---|---|
| Unsteady Flow Log Output File | Stores the computational log and hydraulic solution error computations | /ME_WBGM_009_UG/Mermentau_DS.bco05 |
| Plan HDF File | Contains plan level execution results that focuses on runtime statistics, convergence metrics, and execution status | /ME_WBGM_009_UG/Mermentau_DS.p05.hdf |
| DSS Output File | Stores time series hydraulics output for boundary conditions, 2D/SA connections, reference points and reference lines | /ME_WBGM_009_UG/ME_WBGM_009_UG_Aug2016_100yr_SF1p15/ME_WBGM_009_UG_Aug2016_100yr_SF1p15.dss |
Temporal extent
| 3000-08-01 |
| 3000-08-04 |
Temporal resolution
5SECResource Files
Metadata record information
| Created By | hdr_lwi_region_5@hdrinc.com |
| Created At | 2025-06-24t23:04:39.046692+00:00 |
| Access Level | Public |
| Is Reviewed | True |
| Owner | hdr_lwi_region_5@hdrinc.com |