Back to the drawing board on Hebgen Lake repair (Must read)

I notice a lot of people have been reading this story on the gate failures at Hebgen Dam, the news of which was first brought to us on Sept. 1 by “Idahosal.” (Salle)

They thought they had the way to fix the broken headgates at the dam, but it failed.

Oh Oh1 PPL back to the drawing board on Hebgen repair. AP


Sept. 9

The news now is grim. The bulkhead plan did not work. There was too much turbulence at the dam intake for them to place the steel plate and stem the flow. At the moment there does not seem to be a “plan B”. The flow is still at springtime level. They are losing more than 5 inches of reservoir water elevation every 24 hours and this will accelerate as the level drops due to the cone shape nature of the reservoir bed. There are two scenarios that are scaring us at the moment.

Read the rest at

Sept. 11. Remove boats before they are stranded, Hebgen Lake propert!y owners told. AP

Latest. Sept. 16. Progress slow in Hebgen Dam repair.  By Andy Malby, editor. The Belgrade News






  1. Nathan Avatar

    hello all
    I’ve been following this closely since it occured but have not read anything on the ecological implications of this. Will this have any negative effects? Are there any benefits that could come from this?

  2. Ralph Maughan Avatar

    Salle tells me she thinks the highway is being undermined at a spot about halfway along Quake Lake.

  3. Salle Avatar

    There are references in the article that imply the ecological harm may be wide-ranging. I can see where that could be true. We’re not just talking the Hebgen Lake reservoir, this is the Madison River and eventually, the Missouri. If the lake drains, there will be a lot to consider for the downriver regions.

    We saw bears right where the roadbed seemed a little more ripply than when the runoff was heavy. There’s a steep slope and slides/rolling boulders occur often. the road is cut into the bank and set up on a corridor shelf arrangement that is above the water but the ground about ten to twenty feet below the corridor bed is likely to give way given the greater than normal current that flows through the lake with this release.

    A constant flow of this magnitude at this level can eventually erode too much of the shelf and then the road will go.

    Any engineers out there see what I mean? If any portion of the road gives, US287 will be closed. At this segment of road, from US191 to at least Ennis, cuts off traffic that is not allowed to travel through the park portion of US191, like hazardous materials trucks. Also, that high way is under much construction and has closures for a couple more weeks. This is a major corridor of truck and any other traffic out of the central Rockies.

    If the lake goes, I too, wonder what will happen with some of the wildlife in the canyon and that depend on the lake in general.

  4. TPageCO Avatar

    Do we have an update on this situation anywhere? I did go to the dam website – the flow is still over 3100 cfs and the lake’s dropped over 6 feet.

    Any word from PPL?

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