Hi GD,
This “hole” reveals a crucial problem. In the Original Oroville Dam Geology report, for the “spillway” design, it identifies that rock of “good quality” would be deeper down from the surface. The hole shows highly fractured (or rotten) rock that is structurally unsound in withstanding a “erosion flow” condition.
Why is this a crucial issue? The main spillway is at 814ft (surface elevation of the spillway concrete slabs at the spillway water exit). Using this hole erosion depth (36ft) of fractured/rotten rock and subtracting the original elevation before the hole (833ft), the fractured/rotten rock reveals a depth down to 797ft. This is 17 feet lower than the 814ft spillway concrete slab surface.
Note: This hole is only 303 ft from the west edge of the main spillway channel.
This means that an overtopping emergency spillway reservoir level (901ft) that initiates an accelerated erosion of this now proven fractured/rotten rock level of 797ft is a differential of 104ft.
IF the emergency spillway weir gave way, due to accelerated fractured/rotten rock “back erosion”, the 104ft water height differential & the power of scouring/turbulence would be a major problem (understatement).
This is likely why there is a focus on quickly plugging this location (i.e. rock bags + fast set concrete methods). The problem is that any overtopping would find another weak spot in the emergency spillway fractured/rotten rock.
-— clip from Original Dam Geology report
“An overpour spillway can be utilized at this site by affording moderate protection to the rock near down stream toe. A natural saddle at about elevation 865 and a ravine below it offers a suitable spillway location. Rock of good quality should be found about 30 feet below surface in this saddle.”
Original Dam Geology report link: See page 22 in book copy:
http://www.waterboards.ca.gov/waterrights/water_issues/programs/bay_delta/california_waterfix/exhibits/docs/RestoretheDelta/RTD_101.pdf
Thanks for this data. Very scary.
Are you a geologist or as Sheldon would say a rock guy?
This reply by EarthResearcher333, may be one of the best non govermental reports/analsis of this disaster.
As my good Marine buddies would say what an incredible CF!
Please keep posting these good articles and replies.
Jeff Session might use them before the year is out.
These American refugees 200,000? need help and our donations.
FEMA had a few thousand blankets and a couple of bottles of water.
A Chico state grad friend, said most of these refugees are lucky to have a week or two of savings between them and bank ruptcy.
In the meantime, Moonbeam and our local and national mediots are focusing/crying about the arrests of illegal criminals/felons.
The mediots are showing how evil Trump is because of these arrests, which should have happened years ago during Obama term of welcome to America, illegals, criminals and jihadists.
If Moonbeam had his priorities based on legal citizen needs, proper maintenance would have done on this dam.
Instead illegals got free medical care, cell phones, free school for their kids with free meals at the, ebt cards, and who knows what else besides costly lawyers paid by our tax $’s.
Of course Moonbeam in his liberal senility, spent money on his bullet train from nowhere to nowhere.