2025 USACE SAVA River Workshop

Watershed Scale Sedimentation Analysis using HEC-HMS

Training Description:

The Hydrologic Engineering Center (HEC) of the U.S. Army Corps of Engineers (USACE) is pleased to introduce the incorporation of watershed scale surface erosion modeling, specifically reservoir sedimentation analysis, into its esteemed hydrologic software, HEC-HMS. This significant upgrade empowers HEC-HMS with the capability to accurately compute long-term reservoir sedimentation, both pre- and post-wildfire events. Through sediment trap efficiency methods and dynamic reservoir volume reduction techniques, HEC-HMS now enables continuous updating of elevation area and elevation storage curves, facilitating the simulation of short- and long-term sediment deposition in reservoirs. This workshop aims to leverage these advanced capabilities within HEC-HMS to calculate reservoir volume reduction in both unburned and burned watershed areas.

Objectives:

1. Gain an understanding of the dynamic reservoir volume reduction process and empirical sediment trap efficiency equations incorporated in HEC-HMS.
2. Acquire hands-on experience in developing a comprehensive long-term reservoir sediment model, including parameter estimation, calibration, and utilization of HEC-HMS.

It is recommended that you use HEC-HMS version 4.13-alpha or higher version and HEC-DSSVue version 3.3.29 for the class. You do not need administrative privileges to install HEC-HMS and HEC-DSSVue. Download HEC-HMS version 4.13 alpha (special version for this Workshop) from here (HEC-HMS-4.13-alpha-win-x64.zip). Download HEC-DSSVue version 3.3.29 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-alpha 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:  ~1Q 2025 (TBD)
• Location: Virtual Workshop (Note: Record Lectures!)
• Instructor:
  • Jay Pak, Ph.D., P.E., Sr. Research Hydraulic Engineer, US Army Corps of Engineers, Hydrologic Engineering Center
  • Brantley A. Thames, P.E., Climate Preparedness and Resilience, Headquarters, U.S. Army Corps of Engineers
• Contact: jay.h.pak@usace.army.mil, brantley.a.thames@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.

The First Day (4-Hrs)

The Second Day (4-Hrs)

The Third Day (4-Hrs)

Budget:

• Workshop Budget (2 Instructors):
  • Duration: 3-Day (4 hours/day)
  • Cost Estimation: ~$26K (It will be adjusted based on the circumstances.) 
    • Preparation:
      • Jay: 50 hours
      • 2nd Instructor: 20 hours
    • Workshop Delivery:
      • Jay: 24 hours
      • 2nd Instructor: 24 hours
  • Notes: If there are many participants(more than 15), additional staff from HEC may be required, especially to support virtual sessions.
  • Suggested Alternative: HEC could offer an on-site workshop led by a single lecturer within a similar budget, which may be more efficient than a virtual format.

  • Proposed Adjustments for 4-Day Program (16 hours):

    1. Extend the refresher session to ensure participants have a thorough review of key flow modeling concepts (increase to ~1 hour).
    2. Allocate additional time for lectures and workshops to allow deeper engagement and interaction (~2 hours).
    3. Incorporate a practical sediment modeling demonstration based on UNBRW case studies to provide real-world context and hands-on experience (~1 hour).
    4. Cost Estimation: ~$33K (It will be adjusted based on the circumstances.) 
       • Preparation:
         • Jay: 60 hours
         • 2nd Instructor: 25 hours
       • Workshop Delivery:
         • Jay: 32 hours
         • 2nd Instructor: 32 hours