2026 USSD Workshop

Long-Term Reservoir Sedimentation Analysis using HEC-HMS

4 May 2024 

Austin, TX

Training Description:

Reservoir sedimentation is a critical challenge for water resource managers, impacting storage capacity, flood control, and ecosystem health over decades. This four-hour, hands-on workshop introduces participants to the newly developed dynamic reservoir sedimentation analysis module in the U.S. Army Corps of Engineers’ Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS). By integrating surface soil erosion, channel sediment transport, and reservoir trap efficiency calculations, this tool enables accurate projections of long-term reservoir volume loss under changing land-use and post-wildfire conditions.

Objectives:

The primary objective of this workshop is to leverage the advanced reservoir sedimentation analysis methods within HEC-HMS for facilitating the simulation of short- and long-term sediment deposition in reservoirs. The workshop is structured around two key components:

1. Informative Lectures: Participants will gain an in-depth understanding of dynamic reservoir sediment routing processes including trap efficiency methods. Topics will include dynamic reservoir volume reduction processes and reservoir trap efficiency equations implemented in HEC-HMS.
2. Hands-On Training: Participants will engage in developing a comprehensive long-term reservoir sediment model, which involves parameter estimation, calibration, and practical application of HEC-HMS.

By the end of the workshop, attendees will possess the skills necessary to effectively utilize HEC-HMS for long-term reservoir sedimentation analysis, significantly enhancing their capabilities in reservoir sediment management. This workshop provides a unique opportunity for professionals to stay at the forefront of sediment management technology and apply these methods to real-world scenarios. 

It is recommended that you use this specific version of HEC-HMS for this workshop and HEC-DSSVue version 3.4.18 for the class. You do not need administrative privileges to install HEC-HMS and HEC-DSSVue. Download HEC-HMS special potable testing version 4.14 beta (HEC-HMS-4.14-beta.1-win-x64.zip) only for this workshop. Download HEC-DSSVue potable version 3.4.18 from this page, https://www.hec.usace.army.mil/software/hec-dssvue/downloads.aspx. Then use 7-zip and unzip the files to the C:\Programs directory on your computer (you should have a folder named HEC-HMS-4.13-beta within the C:\Programs directory). Then you can pin HEC-HMS.exe and HEC-DSSVue.exe to your taskbar and open these programs by clicking on the icons.

Workshop Details:

• Time:  Monday, 4 May 2026, 8:00 AM – 12:00 PM (CDT)
• Location: 412
• Instructor: Jang (Jay) H. Pak, Ph.D., P.E., Sr. Research Hydraulic Engineer, US Army Corps of Engineers, Hydrologic Engineering Center
• Contact: jay.h.pak@usace.army.mil
• Instructor Short Biography:
  Dr. Jang (Jay) Pak boasts over two decades of experience with the US Army Corps of Engineers (USACE), currently serving as a Senior Research Hydraulic Engineer at the Hydrology & Statistics Division of the Hydrologic Engineering Center (HEC). His expertise encompasses surface water hydrology, post-fire hydrology, river hydraulics, debris flow analysis, land surface erosion, and more. Dr. Pak earned his Ph.D. and Master’s degrees in Civil and Environmental Engineering from the University of Southern California, focusing his doctoral research on real-time debris prediction models integrating wildfire and subsequent storm events. He is a registered civil engineer in the state of California.

Workshop Agenda: