Never too early to start planning

Published Feb. 28, 2013

The Corps’ Dam Safety Program takes a risk-informed approach to managing its dams – with public safety being the number one priority. The Rock Island District is taking a proactive approach completing six tabletop exercises in the last four years at Lockport Pool, the Farm Creek Reservoirs, Saylorville Lake, Lake Red Rock, Lock and Dam 19 and Coralville Lake.

The tabletop exercises focus on defining risk based on various dam breach scenarios and the potential consequences.

The exercises are held in the communities closest to the dam and include local, state and federal emergency responders and officials within both the immediate impact zone and related jurisdictions.

The exercises aim to educate responders about risk, what information and tools are available, what should be included in their Emergency Action Plan (EAP) or equivalent, and ultimately, to test the Rock Island District’s EAP for each dam.

EAPs provide detailed information on what to do during an emergency. Well-developed EAPs can reduce the severity of emergencies, the risk to the public, economic losses, the potential damage to infrastructure and, most importantly, may save lives in the event of a catastrophic dam emergency.

During the exercises, the Corps facilitated the discussion and talked through their EAP for each location. Background on the Dam Safety Program, definition of risk, and the key components of an EAP were presented, followed by facilitated discussion that steps through a dam breach scenario from initiation progressing to catastrophic breach of the dam. Hydraulic models are used to simulate resulting inundation. The inundation maps generated for the EAP are used as a tool for discussion and stakeholder evacuation planning. One key message in the exercises is that evacuation and response is not the responsibility of the Corps of Engineers. Communities must be prepared in the event of an emergency.

Last fall during an exercise at Coralville Lake two scenarios were played out - one with a dam breach at full flood pool (reservoir pool at the crest of the emergency spillway) and the other for a spillway design flood for both breach and non-breach conditions.

"We use extreme situations to demonstrate the risk," said Matt Stewart, dam safety program manager. "Being prepared for the absolute worst-case scenario is a proactive approach but also ensures we are prepared for those of lesser significance."

We test the EAP during the exercise. A big part of this is risk communication. As we go through the exercise we identify the missing pieces or areas that could be improved through open discussions with the participants."

Following the exercise the Corps’ EAP is sent to all of the participants along with an After Action Review to gather feedback and comments. The Corps then updates their EAP and redistributes copies to all stakeholders for the particular dam.

"The idea is that each group participating would update their EAP or equivalent and provide that to the Corps," said Stewart. "The exercises are communicating the risk but it is each community’s responsibility to develop their own evacuation and preparedness plans and identify what critical infrastructure would be impacted."