This could happen:
Up at the upper reaches of the West Fork at about 10 p.m. as the campers were starting to prepare for a good night’s sleep the water below Painted Rocks Reservoir began to change consistency and color. Being an earthen dam the color of the water started to change more rapidly by 10:30 p.m. Within just a few short minutes holes had opened in the dam and water was gushing through and destroying the dam.
A revised Montana Department of Natural Resources and Conservation Emergency Action Plan relies solely on an observer being at the dam and reporting such an incident on a phone at the top of the dam. As the water gushes through the broken dam and heads on its journey of destruction it immediately takes out all communications and power as it explodes through the narrow canyon and takes away homes tucked into the mountain near the dam and the campground below before speeding towards the West Fork Ranger Station and Connor without any warning.
The 30 foot wall of water with its churning debris of logs and pieces of houses and probably human and animal bodies would reach Conner in about an hour. All communications would be gone at that point and because everyone was unaware of the dam’s inundation they would be in their beds with many children sleeping in basements. Although the speed of the water would slow as the flood water made a turn down the canyon towards Darby it would pick up speed and hit Darby with a 25-foot wave around an hour later covering the whole town of Darby and probably costing hundreds of lives.
This destructive wall of water would reach Hamilton around three hours later with a wall of water and debris in about three more hours and would vary from a wall of water and debris of 25 feet to 44 feet as measured from the top of the water surface in the river at the time.
There would be much more destruction down the river from there all the way to Missoula and Frenchtown. I am not going to take the time now to outline the remaining damage but consider the damage to north of Hamilton. Most of the Fire Departments would be gone from Painted Rocks through Hamilton. Think of the carnage at the hospital and rest homes as the flood followed its course. It would most likely take out the 911 Center as well and it should concern us how much damage it would do to the Rocky Mountain Laboratory. This wall of water would most likely take out all of the bridges that allow the East side to access the West side and would leave the East side without an access to emergency care and to other communities.
There could, given this scenario at this time of night, be thousands dead with hundreds of homes lost and schools destroyed. This would be a Katrina style disaster for our valley.
The same thing could happen if Lake Como Dam was to be inundated at the same time of night. There are two fair size creeks leaking from that dam all the time. Conner and Darby would be spared but the damage down the valley would be very similar to the Painted Rocks scenario. Earthen dams such as Lake Como and Painted Rocks are the most likely dams to fail and all of them leak all the time. They can fail very quickly. Neither dams have Early Warning Systems and our organization hopes to see that change in the near future. Too much is at stake to not have good systems on the dams to protect our families from such a devastating event.
The wave heights and arrival times mentioned come from the Emergency Action Plan. It is amazing that we have to use seat belts by law (I have never needed mine but glad I have it just in case I need it) but government owners of these two dams have no compunction to let most of the population and infrastructure of the valley be at risk for an inundation, no matter the cause without warning systems.
I have asked local authorities and dam owners many times why there are not these protections for our valley:
• Redundant Early Warning Systems (EWS) on both dams.
• Evacuation Routes noted by signage and also available to the citizens through maps and websites to help families know what to do in a threatened or real inundation.
• There needs to be known alarm systems in the valley to warn people of a dam failure so that, in day or night, people know there are flood waters coming and can conduct safe evacuations to avoid injury and death.
Most people that live in this valley have no idea that there are more High Hazard dams in Ravalli County than any other county in the state. High Hazard dams are those that if there is an inundation would cause probable loss of life. And they have no idea that the failure of two of the dams would have such a destructive influence on our valley in the loss of life and property and infrastructure.
Throughout the history of dam failures one thing is quite common. Government agencies (many times the owners such as Painted Rocks and Lake Como) are the ones that hesitate to notify the public of a failure or probable failure. They want to try to do everything first to try to stop the problem. The nearby Teton Dam in Southern Idaho is an example. The Bureau of Reclamation announced that the dam was the best built dam in the country and it would never fail. They waited until the last minute to alert authorities of the dam failure on June 5, 1976 and in fact if there had not been a radio broadcaster at the dam at the time of the break it is very likely that the deaths would have been a lot worse than the 11 people and 13,000 cattle. Estimates were that several hundred more people would have died in the subsequent flooding if it had happened at night when no one was at the dam. They first noticed the probable failure at 7 a.m. and notified the local authorities at around 11 a.m.
It is time for the owners of Painted Rocks Reservoir, Department of Natural Resources and Conservation and the owners of Como Lake, United States Bureau of Reclamation, to show they care about the citizens and families in the Bitterroot Valley. It is alarming to realize that those that inspect and oversee these dams are also the owners, which is a dangerous conflict of interest.
Please join with us in making sure that they do what is right, not what is the cheapest. We ask citizens to speak up and get engaged in this effort to protect this beautiful valley. For more information contact me at SOS Bitterroot, P.O. Box 708, Stevensville MT 59870; dallas@qwestoffice.net; (406)240-5277.
Dallas Erickson
SOS the Bitterroot