The course provides an introduction to the Hydrologic Modeling System, HEC-HMS, focusing both on using the program and performing watershed studies. The course starts with a summary and overview of the program and the mechanics of constructing watershed models. Then, components of the software are studied in detail.  Major modules include GIS tools, data entry, historic precipitation approaches, computing infiltration and excess surface runoff, transforming excess precipitation to runoff, baseflow, and channel routing. Parameter estimation techniques are taught throughout with instruction about model calibration. Instruction material is supported with workshops that illustrate the basic steps of building a model for project applications. A final project is included that ties together topics to create a calibrated model from scratch. 

The following table provides links to YouTube videos for all lectures. Links are provided to the workshop pages located in the HEC-HMS Tutorials and Guides space. All workshop files can be downloaded from the workshops pages as well. Finally, all Power Point files are included below and can be downloaded for reference.  You will need HEC-HMS version 4.8 or newer to open the workshop files. You can download the software from

An archived copy of all the workshop instructions (Workshop and workshop files (Initial Workshop can be downloaded from here

ModuleSubcomponents with LinksPower Point Files

Lecture 1: Overview of Hydrologic Modeling for Studies

Lecture 2: Introduction to HEC-HMS

Workshop 1: Creating a Simple Model

1.      Introduction

2.      Creating a New Basin Model

3.      Creating a New Meteorologic Model

4.      Creating a New Control Specifications

5.      Creating and Computing a Simulation Run

6.      Viewing Model Results

7.      Viewing Observed Flow 

Lecture 3: HEC-HMS GIS Delineation Tools

a)     Georeference Elements using Shapefiles

b)     Terrain Data and other Helpful GIS Datasets

c)      HEC-HMS GIS Data Management

d)      Building Walls and Burning Streams

e)      Automated Subbasin and Reach Delineation

f)       Customize Subbasin and Reach Delineation

g)      Element Naming and Connectivity

h)      Subbasin Discretization

YouTube Playlist

Lecture 4: GIS Parameter Estimation Tools 

a)      Subbasin Characteristics

b)      Reach Characteristics

c)      Parameter Expression Calculator

YouTube Playlist

Lecture 5: Shared Data Components

a)      Time Series Data

b)      Paired Data

c)      Gridded Data 

d)      Gridded Data Import

YouTube Playlist

Workshop 2: Creating a Georeferenced Model using HEC-HMS GIS Tools

1.      Introduction

2.      Creating and Linking Terrain Data into a Basin Model

3.      Preprocessing Terrain Data to Delineate Subbasin and Reach Elements

4.      Using Merge and Split Tools to Customize Subbasin and Reach Delineation

5.      Finalizing the Hydrologic Network 

Workshop 3: Applying HEC-HMS GIS Parameter Estimation Tools

1.      Introduction

2.      Computing Subbasin and Reach Characteristics

3.      Estimating Parameters with GIS datasets

Workshop 4: Introduction to Shared Component Data

1.      Introduction

2.      Creating Time Series Data

3.      Creating Paired Data

4.      Creating Grid Data

Lecture 6: Meteorologic Models - Historic Precipitation

a)      Meteorologic Model Overview

b)      Precipitation Methods

c)      Gage Weights

d)      Gridded Precipitation

e)      Evapotranspiration

f)       Snow Modeling 

YouTube Playlist

Lecture 7: Loss Rate Methods 

a)      Loss Methods Introduction

b)      Canopy and Surface Methods

c)      Infiltration Methods

d)      Initial Constant Method

e)      Deficit Constant Method

f)       Green and Ampt Method 

YouTube Playlist

Lecture 8: Transform Methods

a)      Transform Methods Introduction

b)     Unit Hydrograph Derivation

c)      Clark Unit Hydrograph

d)     SCS Unit Hydrograph

e)      Snyder Unit Hydrograph 

YouTube Playlist

Workshop 5: Meteorologic Models for Historical Precipitation

1.      Introduction

2.      Gage Weights Precipitation Method

3.      Gridded Precipitation Method

4.      Creating an Inverse Distance Precipitation Model 

Workshop 6: Applying Loss Methods in HEC-HMS

1.      Introduction

2.      Applying the Initial Constant Loss Method

3.      Applying the Green and Ampt Loss Method

4.      Applying the Deficit and Constant Loss Method 

Workshop 7: Estimating Clark Unit Hydrograph Parameters

1.      Introduction

2.      Estimating Time of Concentration and Storage Coefficient

3.      Time and Concentration and Storage Coefficient Impacts to the Hydrograph

Lecture 9: Baseflow Simulation

a)      Baseflow Overview

b)      Applying the Recession Baseflow Method

c)      Applying the Linear Reservoir Baseflow Method

YouTube Playlist

Lecture 10: Channel Routing Techniques

a)      Introduction to Modeling Open Channel Flow within HEC-HMS

b)      Lag Method

c)      Muskingum Method

d)      Muskingum-Cunge Method

e)      Selecting the Appropriate Routing Technique

YouTube Playlist

Lecture 11: Model Calibration

a)      Calibration Theory

b)      Calibration Strategies

c)      Parameter Impacts

d)      Calibration Metrics

YouTube Playlist

L 11 a Calibration Theory.pptx

L 11 b Calibration Strategies.pptx

L 11 c Parameter Impacts.pptx

L 11 d Calibration Metrics.pptx

Workshop 8: Applying Baseflow Methods in HEC-HMS

1.      Introduction

2.      Applying the Linear Reservoir Baseflow Method

3.      Applying the Recession Baseflow Method

Workshop 9: Applying Reach Routing Methods within HEC-HMS

1.      Introduction

2.      Applying the Lag Routing Method

3.      Applying the Muskingum Routing Method

4.      Applying the Muskingum-Cunge Routing Method

Workshop 10: Calibrating a Simple HEC-HMS Model:

1.      Introduction

2.      Populate Initial Parameters

3.      Calibrate a Basin Model to Event 1

4.      Calibrate a Basin Model to Event 2

Lecture 12: Model Calibration - Complex Studies

a)      Model Calibration Advanced

b)      Model Calibration Aids

Project: Develop a Calibrated Model from Scratch

Link to Final Project

Project Steps

  1. Download Streamflow Data
  2. Delineate Modeling Elements Using HEC-HMS GIS Tools
  3. Parameterize the Subbasin Element
  4. Add Streamflow and Precipitation Data to the Project
  5. Calibrate the Model
  6. Document Final Model Parameters