Structures that impound large volumes of water or tailings slurries are an inherent threat to inhabitants of low-lying areas downstream. Today most states regulate non-federal jurisdiction dams within their boundaries. This regulation normally entails classification as to hazard level and specifies periodic inspections. With respect to hazard level, dams are generally classified in accordance with a system established by the Federal Emergency Management Agency (FEMA). Dams that fall into the FEMA High and Significant Hazard categories are almost always required to have an Emergency Action Plan (EAP) in place. The contents of a typical EAP will include:

  • Physical description of the dam
  • Limits of the potentially inundated area
  • Triggers that cause the EAP to be implemented
  • Notification requirements
  • Participant responsibilities
  • Public notices and EAP copies
  • EAP exercises and training
  • EAP updating
  • Appendices (maps, assignments, announcements, notification chart, etc.)

D'Appolonia has prepared EAPs for earth embankment dams, concrete-gravity dams and mine tailings impoundments on streams ranging from small creeks to large rivers. We are familiar with the regulatory process for obtaining plan approvals and we have worked with plan participants to incorporate their valuable local knowledge.

D'Appolonia has prepared numerous Emergency Action Plans using the guidance documents illustrated above.

Some example D'Appolonia projects involving preparation of Emergency Action Plans for dams are provided in the following:


Safety Inspection and EAP Preparation for Seven Dams in Pennsylvania

D’Appolonia was retained by the Pennsylvania Department of Environmental Protection (PADEP) Bureau of Waterways Engineering to perform field inspections and to prepare Emergency Action Plans for seven earth embankment and concrete-gravity dams located in several Pennsylvania counties. The scope of work included development of the Probable Maximum Flood (PMF) for each dam and routing the flood associated with a postulated dam breach through downstream channels. EAP documents were prepared and distributed to the EAP participants.

Safety Inspection and EAP Preparation for Six Dams

D’Appolonia was retained by the Mercer County (Pennsylvania) Conservation District (MCCD) to perform field inspections and to prepare Emergency Action Plans for six earth embankment dams located in rural Mercer County. The EAPs were prepared consistent with PADEP requirements and copies were distributed to EAP participants.