Objective - This tutorial will take the user through key steps in building a simple HEC-RAS model.

Data Files

The data for this tutorial are provided below.

SimpleModel.zip

Flow Data.zip

These data are for demonstration purposes only and should not be used for engineering analysis.

Steps

Step 1: Start a new RAS Project

  1. Open HEC-RAS
  2. Create a New Project
    1. Provide a Project Name
    2. Set the Projection for the project (provided) by drag/drop 
    3. Press the Create button


  3. Create a new Terrain by pressing the Add button next to the Terrains group
    1. Provide a Name and press Create
  4. Press the +Add button next to the new Terrain layer and select the Import File option
  5. Select the USGS_Original.tif file (provided)
  6. Press the Import button
  7. Zoom to the extents of the new Terrain layer.


Step 2: Create a New Geometry

The study area for this is example is shown in the figure below.

  1. Create a new Geometry by pressing the Add button next to the Geometry group
  2. Provide a Name and press Create
  3. Turn on the Conceptual Mesh
  4. Select the Conceptual Mesh
  5. Select the Edit Tool
  6. Create a polygon for the area of interest
    1. Double-click to begin drawing
    2. Click to add a vertex
    3. Double-click to finish an Arc
    4. Connect a series of Arcs to create a Polygon
  7. Click the quick-edit icon to choose a the Cartesian Mesh Cell Type and set the Cell Size to 500 (ft)
  8. Click the Regenerate Mesh button
  9. Use the quick-edit icon to change the Cell Size to 200 (ft)
  10. Click the Regenerate Mesh button

Step 3: Set Manning n values

  1. Select the Surface Layers group and press the Add button and choose the Add Manning n Layer option
  2. Provide a Name and press Create
  3. Enter 0.05 for the Constant value

Step 4: Create New Boundary Conditions

Establish boundary conditions with an upstream inflow hydrograph and normal depth at the downstream.  You will be modeling a flow event from 01 January 1997 0000 to 05 January 1997 1200.

  1. Select the Boundary Conditions group and press the Add button
  2. Provide a Name for the event and enter a time window (shown below)
  3. Select the Boundary Condition Lines layer (and turn it on)
  4. Create the Upstream Inflow Boundary Condition
    1. Zoom to the upstream end of the model
    2. Use the Edit Tool to create an Inflow BC
    3. Press the ? button and then click the Name field and enter Merced Inflow
    4. Press the ? button and then press the Attach Data button
      1. Select Flow for the Variable
      2. Select Tabular for the Data Mode
      3. Press the Create button
    5. In the Components panel, select the Hydraulic Data payload
    6. Set the time Interval to 15 Minutes
    7. Open the FlowData.xls file
    8. Copy and Paste the flow data into the Merced Inflow boundary condition data table
  5. Create the Downstream Boundary Condition
    1. Zoom to the downstream end of the model
    2. Use the Edit Tool to create a BC line
    3. Press the ? button and then click the Name field and enter Downstream
    4. Press the ? button and then press the Attach Data button
    5. Select the Normal Depth option
    6. Set the Normal Depth Slope to 0.001
    7. Press the Create button

Step 5: Create a New Plan

  1. Select the Plans group and press the Add button
    1. Provide a Name - January 1997
    2. Select a Geometry - Base
    3. Select a Boundary Condition - January 1997 Event
      Note that the Time Window is automatically populated.
    4. Press the Create button


Step 6: Simulation the Plan

  1. In Components panel, press the Compute button
    The run will commence
  2. The Compute Log will show Progress
  3. The Plan will show it is running


Step 7: Evaluate Hydraulic Results

  1. Select the Plan Results
  2. Select Depth
  3. Animate the Depth grid using the Time Series bar
  4. Switch the output to Water Surface
  5. Move the mouse over the map to see Water Surface Elevations
  6. Right-click over an inundated area and choose Query Time Series
  7. Select the Profile Lines layer and create a profile line down the river channel.
  8. Right-click on the River line and choose the Plot | Results Profile menu option