SacBee news with interesting info. They can't get the formulations of crushed rock from the reclaimed stockpile to work (RCC intended use). This could be a significant disaster in that IF they were planning on using this material for the voluminous RCC construction repairs & building to quality standards of ES & MS new spillways. They would need a plan "B" to get known quality rock & materials to meet schedules. But this would be equivalent to trucking in nearly the same volume of the stockpile with "known good" RCC base rock & material.
Other news in this article are that new plans are afoot inferring that only "minor work" will be done in the Upper Main Spillway in 2017, leaving the upper spillway "mostly untouched".
Article excerpts: === (emphasis mine)
"In a 16-page report made public late Wednesday, the engineering consultants concur with DWR’s plan to leave the dam’s upper spillway mostly untouched this summer while focusing efforts on the heavily damaged lower spillway."….."However, DWR redacted five paragraphs that spell out the consultants’ recommendations for making the plan work."…..
"The consultants’ report, their fourth, was more heavily redacted than the previous memos released by DWR. Erin Mellon, a spokeswoman for the Natural Resources Agency, which oversees DWR, said the latest report contains more information that was considered “critical energy infrastructure information,” or CEII. That rule, intended to prevent terrorist attacks, allows DWR to seal sensitive information."…..
“There was more CEII in the fourth consultants’ memo,” Mellon said Thursday."…."In their memo, the consultants also sign off on DWR’s plan to fill in the gaping chasms in the spillway with fast-drying concrete made from recycled rock that’s been recovered from the Feather River channel below the dam. However, they add that so far the methods used for crushing the rocks don’t produce “suitable material” and need to be refined.….
== end excerpts.
Oroville Dam: The latest on spillway repairs – and what state won’t tell us
Concrete mix quality discussion: stockpile rock vs "known quality" aggregate
Asbestos found in stockpile rock - DWR treating site as "contaminated".
http://www.water.ca.gov/news/newsreleases/2017/050417news.pdf
Questions about “green spots” on Oroville Dam
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The green stripes, or vegetation, pose no threat to dam safety. Oroville Dam is sound and safe.
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DWR has determined that these green stripes are caused by rainwater falling on the face of the dam and seeping into soil layers, causing grasses and weeds to grow in rainy spring seasons.
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This has been the conclusion of numerous independent cons
ulting boards convened at five-year intervals over several decades. This vegetation was first noticed on the dam prior to the reservoir being filled in the mid-1960s.
“There was more CEII in the fourth consultants’ memo,” Mellon said Thursday.”….”In their memo, the consultants also sign off on DWR’s plan to fill in the gaping chasms in the spillway with fast-drying concrete made from recycled rock that’s been recovered from the Feather River channel below the dam. However, they add that so far the methods used for crushing the rocks don’t produce “suitable material” and need to be refined.….”
Thank you, ER333, for this week's analysis and the above official news. I had jumped on the thread to see if the snow melt is causing trouble yet. I've been reading the daily outflow/inflow summaries at the DWR reservoir site. So far the dams below Oroville are max capacity while the managers keep Oroville beneath 80% capacity. Shasta today is almost at 100%. My question is: when does the snow pack melt usually reach its peak and/or has the massive amount of snow mostly melted by now? I'll ping Ray76 over to see what he knows.