Here is the significant (some noted as "car sized") bubbles that were surfacing in front of the Emergency Spillway. The equivalent water displacement for these sized & number of "bubbles" indicates a penetrating flow. Where to has not been discussed by authorities other than unconfirmed reports of "leaks" (scanner traffic). Maggief has more info on the "reports" in some of her excellent detective work.
It would be interesting to see a video of that, to see if they are in fact bubbles. There are no ripples from any prior bubbles, and the camera just so happened to be here when the bubbles appeared. Maybe they’re just reflections. Need video.
At the last video I saw before the water began to recede, there were a couple of spots below the emergency spillway, near the main spillway that shows streams of water coming out like fire hoses. The impression I had was that there were two streams of water, under pressure working their way beneath the emergency spillway.
I agree they are withholding data from the public, but I would expect that examination on the lake side of the spillway would reveal where water was escaping. They can't afford to ever let the water get this high again. Northern California dodged a bullet.
This image reveals a large 2foot diameter metal drain pipe buried under the footing elevation of the Emergency Spillway. This photo was taken before the flooding (overtop of the spillway). Notice the waterflow. A pipe of this size, and the angle it is projecting puts it underneath the ES Weir, would be unusual to drain the soil in the immediate vicinity (normal rainfall on the topsoil).
The Emergency Spillway blueprint design has the Weir as a concrete shell with aggregate fill. Drains are designed in the footing of the bottom of the aggregate horizontal to the elevation of the footing.
The blueprint design drawings indicate the Wier is sitting atop a rock foundation. But the type of rock may be what has been revealed in the deep cut erosion (hard rock but fractured or weathered rock).
What is also interesting is that this 2foot diameter drain is close to the opposite side of where the bubbles occurred. That drain pipe may have been a good indicator to any increased water underflow to the substructure of the ES Weir when flood levels occurred (just before and just after the cresting of the Weir).
