Responding to Dam Emergencies

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Many dam failures have been averted by dam owners and engineers taking quick and effective action to intervene and stop an active dam failure from progressing. The focus of this webinar is to present the most common failure modes at dams and provide information on actions that can be taken to prevent or delay each failure mode. Case studies will be used to show examples of successful interventions. Actions that could potentially do harm and make conditions worse will also be discussed. The seminar will conclude with an overview of the new “Dam Intervention Toolbox” and how this interactive resource can be used as a companion to an Emergency Action Plan to help dam owners be better prepared to respond to a dam emergency.

Five Learning Objectives of This Course:

• Understand the most common failure modes at dams.

• Know what emergency measures can be taken to stop common failure modes at dams.

• Be aware of actions that can potentially make conditions worse.

• How to become prepared to respond to a dam emergency.

• Learn about the new “Dam Intervention Toolbox.”

Paul G. Schweiger, P.E.

Vice President, Gannett Fleming, Inc.

Paul is a Vice President of Gannett Fleming, Inc. and Manager of the Firm's Dams and Hydraulics Section in Camp Hill.  He has over 33 years of consulting engineering experience and has served as a project engineer or manager for the design of eleven new dams and the design and technical review of many dam rehabilitation projects.  He has inspected hundreds of dams across the nation including completing over 200 dam assessment reports.  Paul is an approved FERC facilitator for performing potential failure modes analysis exercises for dams, Emergency Action Plan exercises, and Part 12 dam assessments.  He regularly serves as an expert hydrology and hydraulics engineer on Independent External Peer Review panels for United States Army Corps of Engineers dam and flood control projects and has served on the National Dam Safety Review Board as the Private Sector Representative.  Paul is currently serving on the Board of Consultants for the Oroville Spillway Emergency Recovery Project and the Oroville Dam Comprehensive Needs Assessment.

Greg Richards

Gannett Fleming, Inc./Senior Project Manager

Greg Richards is a Senior Project Manager responsible for management and execution of projects related to hydraulic structures such as flood control reservoirs, spillways, outlet works, stilling basins, bridges, and stream channel improvements. Technical specialties include performing hydraulic and hydrologic (H&H) analyses for dams, conducting dam assessments, completing regulatory Federal Emergency Management Agency floodplain analyses and map revisions, assessing bridge scour, performing dam failure inundation analyses and mapping, designing labyrinth spillways, and estimating reservoir safe yield.  Greg co-authored the FEMA funded Dam Emergency Intervention Toolbox.  He is also an active member of ASDSO and serves on the ASDSO Dam Failures and Incidents Committee.

  • 1. Introduction:
    • a. Why This Topic Is Important
      • i. Share statistics on recent dam failures and consequences
      • ii. Being prepared to intervene to stop or delay an active dam failure is often overlooked and not included or elaborated upon in many EAPs.  Response time is limited and being prepared is the key to success.
      • iii. Benefits of an effective intervention (Prevent failure, provide more time to warn and evacuate, reduce consequences)
      • iv. Consequences of a harmful intervention 
    • b. What You Will Learn
      • i. Most common dam failure modes
      • ii. Actions that can be taken to prevent or delay each failure mode
      • iii. Actions that should not be taken, or that should be taken with caution – do no harm!
      • iv. Examples from case studies of responses (successful and unsuccessful) to actual dam emergencies
      • v. Know where to find the best resources
  • 2. Most Common Dam Failure Modes
    • a. What Is A Dam Failure Mode?
    • b. Most Common Dam Failure Modes and Early Warning Signs
      • i. Seepage and internal erosion (piping, ….)
      • ii. Spillway Erosion
      • iii. Dam Overtopping
      • iv. Structural instability (slope instability, sliding, overturning, settlement)
      • v. Other
  • 3. Intervention
    • a. Intervention Action Common to All Dam Failure Modes – Lower the Reservoir!
      • i. First, do no harm by making releases
        • 1. Loss of resource consequences
        • 2. Potential downstream consequences
        • 3. Potential structural consequences
        • 4. Potential loss of outlet control
      • ii. What to do if you do not have operable outlet works
        • 1. Siphons
        • 2. Controlled breach
        • 3. Lower downstream reservoir to contain or absorb breach flows (special case)
    • b. Seepage and Internal Erosion
      • i. Plugging leak from upstream side
      • ii. Reducing hydraulic gradient from downstream side
      • iii. Intercepting and filtering seepage
    • c. Spillway Erosion
      • i. Divert flows away from eroding area(s)
      • ii. Armor eroding areas
      • iii. Stopping or limiting erosive flow
    • d. Dam Overtopping
      • i. Lower reservoir in advance of pending flood
      • ii. Raise dam
      • iii. Armor dam
      • iv. Construct auxiliary spillway
  • 4. What About Being Prepared to Respond to Public Safety Incidents?
  • 5. Available Resources
    • a. Dam Owner Emergency Intervention Toolbox
    • b. ASDSO/FEMA Lessons Learned from Dam Incidents and Failure Website


On- Demand Webinar
Open to view video.
Open to view video.
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5 Questions
5 Questions Post Survey
Completion Quiz
10 Questions  |  3 attempts  |  6/10 points to pass
10 Questions  |  3 attempts  |  6/10 points to pass
Completion Certificate
2.00 PDH credits  |  Certificate available
2.00 PDH credits  |  Certificate available