Easy and Quick Determination of the PMF from the PMP Using Free Tools: Agenda

January 14, 2025
12:00 PM - 2:00 PM Eastern

Short Background on Probable Maximum Precipitation (PMP)
- Hydrometeorological Reports (National Weather Service)
- Statewide PMP studies
- Site Specific PMP studies
- Seasonal / Rain-on-snow studies
- Recent challenges to the maximum predicted values
- Probability when used with risk-informed decision making
Transformation of PMP values to the Probable Maximum Flood (PMF)
- Hydrologic inputs needed
  - Watershed/Drainage area boundary
  - Rainfall (gridded vs. point)
  - Topography (resolution vs. accuracy)
  - Land cover
  - Soil
  - Local hydraulics (dams, bridges, culverts and diversions)
Q&A on PMP and Hydrology
Continuation on Transformation of PMP values
- HEC-HMS
  - Importing rainfall data
  - Developing the 2-D mesh and sub-watersheds
  - Importing hydrologic parameters
  - Adding a hydraulic structure
  - Running the model
- HEC-RAS
  - Importing rainfall data
  - Developing the 2-D mesh
  - Importing hydrologic parameters
  - Adding multiple hydraulic structures
  - Running the model
Calibration and verification techniques
- Historic values
- Steam gauges
- Reservoir history
Presenting the analyses
Q&A on Modeling