The course covers a variety of areas that go beyond the Basic HEC-HMS course which focuses on event-based flood hydrology.  This course contains modules on continuous simulation, including the details of modeling water content in the soil, evaporation and transpiration, and details of the components included in HEC-HMS for representing these processes.  This course also contains modules on model calibration and validation, snow processes and snowmelt modeling, parameter optimization, uncertainty analysis, modeling frequency and hypothetical storms, and ensemble analysis.  A final project is included that ties together the various lecture and workshop topics that were introduced throughout the week.

The following table provides links to all lectures and 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 PowerPoint files are included below and can be downloaded for reference.

You will need HEC-HMS version 4.11-beta.9 or newer to open the workshop files. You can download the software from

Lectures and Workshops


PowerPoint Files

Lecture 1: 

Model Calibration and Validation

Explanation of model calibration versus model validation.  Discussion of techniques and statistical metrics used to evaluate model performance.

Lecture 2: 

Continuous Simulation Methodologies

Explanation of differences between event and continuous simulation.  Description of the soil moisture accounting and deficit constant methods that can be used for continuous simulation.

Lecture 3


Explanation of the physical process of plant water use and approaches to simulating evapotranspiration.  Discussion of the importance of evapotranspiration in the water balance over long time periods, the methods available in HEC-HMS for modeling ET.

Workshop 1: Calibrating and Validating a Single Event Model

Practice calibrating single event models and explore different calibration techniques.  Validate a model to independent events using parameters from model calibration.

Calibrating and Validating a Single Event Model

Workshop 2: Calibrating a Continuous Simulation Model

Practice calibrating continuous simulation models.  Explore the effect of different methods for representing evapotranspiration.

Calibrating a Continuous Simulation Model

Lecture 4: Case Study of a Continuous Simulation Model for the Russian River Watershed

Discussion of the application of HEC-HMS to the Russian River Forecast Informed Reservoir Operation (FIRO) study and how the HEC-HMS model was developed and calibrated.

Lecture 5: Gridded Data Import and Manipulation

Discussion of gridded data sources.  Downloading, importing, and using within HEC-HMS are also discussed.

Lecture 6: Snow Hydrology and Data

Brief history of snowmelt/accumulation modeling.  Explanation of the physical processes at work during snow fall and pack accumulation.  Discussion of the role of ripening and pack melt.  Introduction to the types of atmospheric data required for snow modeling.  Discussion of methodologies used to collect information about the snowpack.  Sources of data and appropriate processing procedures.

Lecture 7: Snowmelt Modeling Methodologies

Introduction to the temperature index, hybrid, and energy budget snow modeling methods along with guidance on parameter estimation.  Discussion of parameter calibration techniques, optimization, and uncertainty.

Workshop 3: Point Snowmelt Calibration

Review atmospheric data and prepare a Meteorologic model for use with all available snow modeling methods in HEC-HMS.  Become familiar with the available snow modeling methods using a point watershed.  Calibrate using data from a SNOTEL.

Calibrating Point Snowmelt: Swamp Angel Study Plot, Colorado

Workshop 4: Gridded Snowmelt Calibration

Become familiar with the available snow modeling methods using a gridded watershed.  Calibrate using SNODAS data.

Calibrating Gridded Snowmelt: Upper Truckee River, California

Workshop 5: Downloading and Importing Gridded Data

Download, import, and edit gridded data.  Use gridded data within an HEC-HMS project.

Workflows for Downloading, Importing and Manipulating Gridded Data

Workshop 6: Manipulating Gridded Data

Use the Grid To Point tool to calculate subbasin-averaged SWE from SWE grids and the Normalizer tool to create a normalized precipitation grid that captures the temporal variability of one gridded dataset but the cumulative volume of another gridded dataset.

Part 2: Manipulating Gridded Data

Lecture 8: Case Study of a Gridded Snowmelt Model for the Columbia River Watershed

Discussion of the application of HEC-HMS to the Columbia River study and how the HEC-HMS model was developed and calibrated for a multi-million dollar study which evaluated alternative reservoir operation scenarios within the Columbia River watershed.

Lecture 9: Reservoir Modeling Methodologies

Modeling reservoirs using the HMS Reservoir element, including specified releases, outflow curves, outflow structures, rule-based reservoir routing, and sedimentation.

Workshop 7: Modeling Reservoir Operations within HEC-HMS

Utilize multiple Reservoir options to simulate reservoir storage, elevation, and releases.

Modeling Reservoir Operations with HEC-HMS

Lecture 10: Model Optimization Methodologies

Understanding model optimization using HEC-HMS, including the Simplex and Differential Evolution search methods, strategies for effective optimization, parameter estimation, and flood maximization.

Workshop 8: Model Parameter Optimization

Use the Simplex and Differential Evolution options to optimize model parameters.

Applying Simplex and Differential Evolution Optimization to Single Event Calibration

Lecture 11: Model Uncertainty Methodologies

Describe various sources of uncertainty in hydrologic modeling results and ways in which they can be quantified using the Uncertainty Analysis within HEC-HMS.

Lecture 12: Optimization and Uncertainty Analysis Case Study - Optimization and Transposition of Historical Storms

Use of the HEC-HMS Optimization Trial and Uncertainty Analysis for exploring the flood impacts of real storms using a what-if approach.

Workshop 9: Application of the HEC-HMS Uncertainty Analysis Compute Option

Use the Uncertainty Analysis to explore uncertainty in outputs that are due to various hydrologic process.

Applying the Uncertainty Analysis Compute Option in HEC-HMS

Lecture 13: Frequency and Hypothetical Storm Methodologies in HEC-HMS

Discuss hypothetical and frequency storm precipitation methods in the HEC-HMS Meteorologic Models. Investigate storm area, temporal patterns and other critical components. 

Workshop 10: Frequency Storms

Use the Depth-Area Analysis to develop flow-frequency curves at multiple locations.  Also, develop custom depth-area reduction curves and compare against those from NOAA Atlas 2.

Applying the Frequency Storm Met Model in HEC-HMS

Workshop 11: Hypothetical Storm

Use the Hypothetical Storm option in order to estimate flow-frequency at various points of interest.  Utilize multiple temporal and spatial distribution patterns.

Applying the Hypothetical Storm Met Model in HEC-HMS

Lecture 14: Ensemble Analysis

Present the Ensemble Analysis along with example applications.  Describe goals and outputs of a typical Ensemble Analysis.

Demo: Ensemble Analysis

This demonstration will be provided live

Final Project: Calibrate, Validate, and Apply a Complex Model

This final workshop combines information from all lessons and workshops and gives you another chance to calibrate, validate, and apply an HEC-HMS project.

Advanced Applications of HEC-HMS Final Project