11 thoughts on “Photo Sunday, 4/11: 10 Aerial Photos of Rat Creek rebuild

  1. Kudos to the engineers and crews that constructed this. Appears to be thoughtful and well executed. Plus, they have expertly matched the soil color 🙂

    Is Rat Creek not presently flowing? Appears to be dry. Perhaps there is an unseen bypass? Or drought?

  2. Of course the project isn’t finished, but so far I haven’t seen then main culvert that should be properly bedded onto/into competent rock. Is the equipment obscuring the intake? Where is the outfall? The two “overflow” CMP’s that seem to be resting on top of the fill slope do not appear to be complete, but if they are–no, I can’t believe that they would be designed to discharge the outflow above the toe of the slope. Again, if CALTRANS had supplied the public with their plans and specifications, this sort of interpretive observation would not be necessary. Are they releasing selected pix for any reason? This reason? Is anyone doing independent drone work? We need closeups of the toe and discharge as well as the intake works. I shudder to think what will happen to animals, including humans, that might be sucked into these culvert intakes; even if they do install debris “filters,” the pressure would be impossibly severe. At flood, what will be the total consequences of the forces created by that much water at that velocity and weight contained in a CMP at that steep a gradient?

  3. I have a lot of respect for engineers too, but I do “fear” that there is too much politics involved and too little public engagement. It is a rare engineer who will stand against tradition or the group. Admiral Rickover insisted that minority reports be attached to the “consensus” reports. That didn’t use to happen in CALTRANS (and almost every public agency and most private corporations), and I strongly suspect that it does not happen today. When the Loma Prieta Earthquake flattened the Cypress Viaduct Freeway in 1989, killing 42 people outright, a single CALTRANS engineer said that he had for years pushed for encircling steel to be added to the structural supports for earthquake resistance. I only heard him say it on TV once; then I never heard of him again. However, a lot of overpasses and similar structures were retrofitted after that. I have no way of knowing what might have been the case here. Apparently, secrecy rules. Some engineers do engineering; others use “standard” specifications. Still others use “intuition.” Nothing wrong with intuition; Robert Maillart was an intuitive engineer–that is, he combined the two.

  4. W. I have come to the conclusion that we will get quik fixes from here on out. Not built to last for years,just a season or three. There is simply to much revenue being lost by the day,by the trifecta of taxation. Gas,hotel car rental. The cost to pay out ratio gets screwed the longer the drive thru Disney ride remains closed. There is TREMENDOUS political pressure to get this thing up and running asap.

  5. The uphill side should receive a thick coating of 12″-24″ sharp rock over the raw soil & around the culvert input.
    Or equivalent. That will be coming soon.

  6. The big (“overflow” culvert doesn’t appear to have a steep enough gradient to get the velocity WAY up, but the two smaller ones can probably be expected to build up excessive pressures and cavitation might (likely will?) be significant. The “suction” and the inlet will be a magnet for debris, and internal clogging (almost impossible to remove) can likely be added to the the list of headaches–to put it mildly, BECAUSE they appear long enough to take a log. At the outlet, the discharge pressures are likely to be very great. Of course, I hope this has all been carefully engineered with models and everything rather than based on standard specifications and guesswork.

    There is likely to be considerable turbulent flow at the inlet to, to the point, I fear, that mere armoring alone might not do. Probably the bigger the headwall, the better, but then, hey, maybe a bridge would begin to look cheaper in the long run.

    Watch this video. It mimics what happened here on a smaller scale https://www.youtube.com/watch?v=d69gaCaV5Wk Go to 17:00–44:15. Watch closely and re-run and stop as necessary to get a full understanding.

  7. Bridge would have been such a better, although longer process. Nature would have a canyon. I give this 10 years before issue arise and 20 before it blows

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