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Painted Rocks dam – with no overflow system

In honor of California’s dam problems, the local Ravalli Republic newspaper just published an article on The Painted Rocks dam. Probably more thanks to the agitation of Dallas Erickson than the threatening disaster of Oroville.

If you have been watching the unfolding drama as the crumbling dam gets pushed to, and perhaps beyond its limit, you know that the main spillway damage first observed 4 years ago has now rendered that spillway hazardous to use. The emergency overflow was deemed inadequate and unusable 12 years ago. Surprise, surprise, surprise, turns out that it is indeed unusable without catastrophic erosion.

Several years ago, California politicians pushed through a “water bond” to fix aging and at-risk water infrastructure. They spent that money on social programs instead. The dam work was never done. Today they pretend this was unforeseeable and, along with their co-conspiratory captive media, find themselves not only blameless, but valued resources in prevention and mitigation.

Our local politicians and infrastructure managers are in that same position. The time to ENCOURAGE them to action is now. Relevant contact information is at the end of this article:
http://www.bitterrootbugle.com/2017/02/14/dam-threatens-bitterroot/

As Dallas points out, most people underwater in this scenario have never been told about the estimate, the risk, any plan to evacuate, and certainly of warning systems that do not exist.

Teton dam blowout – similar design to Painted Rocks – wiped out two towns downstream.


What exactly does Emergency Management for Ravalli County do?

Some will make their own estimates that are far less devastating. That is all well and good. So instead of 10,000 dead Bitterrooters it may be only 3,000. Does that somehow make it okay?

Is there a plan B if there are no bridges over the Bitterroot River between Victor and Sula? … or, said another way, between Victor, MT and Salmon, ID?

From the Ravalli Republic:

Stevensville man calls for early warning systems on Ravalli County dams

Dallas Erickson has been a longtime advocate of some type of early warning system on two of the largest dams in the Bitterroot Valley.

With the latest scare of a near catastrophic dam failure at Oroville, California, the Stevensville man is hoping that people will take another look at the issue.

The operators at both Painted Rocks and Lake Como said those structures are checked on a regular basis for any abnormalities and inspected frequently by specially-trained engineers.

Erickson recently formed a group he calls SOS the Bitterroot that will advocate for some type of early warning system on both of the earthen dams.

If either one of those dams were to fail, Erickson said they could send a wall of water up to 50 feet high that would destroy infrastructure past Corvallis.

“The scary part to me is that many people don’t even know that they are under that threat,” he said.

Larry Schock is the Montana Department of Natural Resources engineer charged with managing the dam at Painted Rocks, which was constructed in 1939.

Under state dam safety rules, any dam whose failure would cause damage downstream is considered a high hazard dam.

Dams managed as state water projects – like Painted Rocks and Lake Como – are required to be inspected annually by licensed professional engineers.

“The rules are in place to ensure public safety,” Schock said.

Dallas writes:

“Schock and others spend a good deal of time throughout the year checking water levels and the general condition of the dam. Unlike the dam at Oroville that ran into troubles when water began to run over a secondary spillway, Schock said Painted Rocks’ primary spillway is designed to handle the probable maximum flow during high water events.”

Notice that it says “probable maximum flow”. That is what the Oroville dam spillway was designed to do. Now if he would complete the thought he would have to say, “However, if we get an unusual storm then it could wash out that dam because the spillway would fail”. Office of Emergency Management made a statement that indicated 10,000 people could be killed by such an event.

Larry Schock was also reported to have said: ““We are always willing to work with the community,” he said. “We worked with a group in Gallatin County and installed an early warning system on Hyalite Canyon when we did some rehabilitation work there.”

My question is what are we waiting for? The dam to break or threaten to break. Let’s get it done.

This is what their own study says would happen. What if it happened at 11:00 PM?