WEST YELLOWSTONE – The mythical scenario was horrible – an earthquake in Yellowstone National Park has caused the failure of Hebgen Dam; a wall of floodwater is heading down the Madison River and will be at Ennis in little more than eight hours.
Of course, this was only a fictional storyline, but it set the stage for an exercise in which officials from three counties and several government agencies worked to test the effectiveness of their emergency response systems.
The exercise was held last Wednesday in West Yellowstone as part of a requirement from the Federal Energy Regulation Committee, said Jim Stilwell, spokesman for PPL Montana, the company who hosted the event.
PPL Montana owns and operates both Hebgen and Madison Dams on the Madison River. The purpose of the emergency response exercise was to allow PPL, along with government officials and agencies to work through any kinks in Hebgen Dam’s emergency action plan. The idea was to simulate a catastrophe that would test everyone’s capabilities.
“Hopefully from this we’ll determine whether the (emergency action) plan is effective whether it’s a good plan and needs to be modified at all,” Stilwell said.
The simulation began at about 10 a.m on the Fourth of July weekend with news of the earthquake and the dam being breached. Nineteen minutes later, the wall of water from the dam had flooded Campfire Lodge and the adjacent campground, which are situated between Hebgen and Earthquake Lake. Officials from both Madison and Gallatin County, along with Forest Service and Bureau of Land Management officials worked quickly to implement evacuation procedures for the recreation facilities along the upper Madison River.
Immediately, Madison County officials began to set up communications with emergency responders and to work to establish a command center in Ennis.
Madison County Commissioner Jim Hart was appointed to serve as the public information officer and fielded questions from the media.
In the mock event, the scenarios that played out were real possibilities. If Hebgen Dam did catastrophically fail, all of lower Ennis and the surrounding lowlands would be flooded by nearly 20 feet of water. Chances are Madison Dam wouldn’t be able to contain the waters coming into Ennis Lake and would also fail. Three Forks would be flooded, so would Townsend. In fact, a failure at Hebgen Dam could cause flooding in Great Falls as Canyon Ferry Dam released high flows to accommodate the influx of water from upstream.
The flooding would result in thousands of evacuations, millions of dollars of property damage and widespread power outages. People would be injured and some would probably die. Travel in the area would be severely limited, as would communication.
“It’s just a possible nightmare,” Hart said. “I hope to hell we never have to face that.”
But central to being able to deal with it as effectively as possible would be communication, both between emergency responders and officials and with the public, he said.
“The biggest thing I got out of the exercise was the possible communication difficulties that arise in any event,” Hart said. “To me we can never have enough of those exercises to nail down adequate communication.”
It might seem like Hebgen Dam failing is an event unlikely to ever happen, but for Madison County officials, the possibility of facing such a scenario is very real, said Madison County Communications Coordinator Steve DiGiovanna.
“We actually had an imminent dam failure in 2008,” DiGiovanna told the group at the exercise during the critique after it was finished.
He was referring to Labor Day weekend 2008, when problems at the Hebgen Dam intake caused a malfunction that resulted in flows of about 3,000 cubic feet per second out of the dam. Those flows were more than three times the normal flows, but still not enough to cause flooding down stream.
However, the initial word from PPL officials at the dam was that it was failing, DiGiovanna said.
“When you’re in the dispatch center and you hear that call come in, you really have to pinch yourself,” he said.
For about two hours, county officials believed they were dealing with the worst possible scenario. When it turned out the dam wasn’t failing, it gave everyone a chance to go back and look at what was working and what wasn’t, DiGiovanna said.
It’s crucial that information come out early from PPL officials, he said. When dealing with flooding and a catastrophic dam failure, minutes and seconds matter immensely for both citizens and emergency responders. The exercise in dealing with a mythical dam failure helps with that.
“We’re there to be certain that we emphasize how important it is that the process be started early,” DiGiovanna said.
Many Madison County officials took part in the training, including sheriff Dave Schenk and undersheriff Roger Thompson, emergency management director Chris Mumme, public health administrator Jill Steely and commissioners Jim Hart and Dan Happel.
It was crucial for all of them to be in attendance and the public needs to understand that emergency management is something the county takes seriously, DiGiovanna said.
“Citizens (in Madison County) can take some comfort in knowing that people in law enforcement and the rescue services and the emergency services, that even though they may not realize it, we’re constantly working to be prepared,” he said.
And taking the exercise seriously is the only way to get out of it what you should, Stilwell said.
“We at PPL are happy and grateful these folks attend who participated so enthusiastically,” he said. “All in all I think we found out that people were pretty well prepared.”