Early designs had the MS flowing down the hillside like the current ES. The design was discarded because designers knew the spillway hill was problematic.
It seems to me the new design should have some redundancy for the MS (perhaps an armored channel for the ES, perhaps an independent secondary gated spillway) or protection for the power plant (if there is a flood situation forgo the electric generation and protect the plant, perhaps with gates). Hindsight is 20/20, unless the lesson is ignored. Rebuilding the existing design doesn't mitigate the MS being a critical point of failure. But I'm not a dam engineer.
In the past week or two someone posted "do it while the money is flowing". I agree 100%. Now is the time. Coming back in 5 or 10 years for more money ain't gonna fly.
Source:
California State Water Project, Bulletin 200, Vol 3, page 93 (1974)Hi Ray76, (& others getting up to speed).. That "clip" section of the archives was the result of the original design findings in the HYD-510 analysis. That section revealed a series of "engineering judgement" chain of events that started this hillside erosion consequence "hot potato" (Emergency Spillway ES).
Even though the "cash is flowing" - (FR KC Burke quote) - the new proposed concept design Emergency Spillway with RCC buttressing and a partial downhill "apron" still has a serious design flaw of repeating the whole crisis chain of events. DWR is making the same "engineering judgement" shortcoming as in the early "Politics of Engineering" back in the 1960's. The links below, (first one has the clip you noted), provide a series of clickable reads to cover past postings of these discussions (& graphics).
FRpost links: (volumes of photos, diagrams, discussion):
Politics of Engineering Judgement: How Failure is introduced…
DWR's 1960's Split spillway "engineering political solution" coming back to haunt the future? (new Failure mode of the entire dam)
How can the spillway be brought to modern design standards based on spillway design history and other dam failure knowledge gained?
Modern Spillway Design vs Oroville Design - 2 Dam Failures, Drain Pipe, Rebar, "Hydraulic Jacking", "Void" Finding by Radar
More:
The panel report also said that while touring the spillway, consultants spotted “extraordinarily large” amounts of water gushing out of drains...
Expert Board of Consultants swizzled flow number specifications for the New Main Spillway and the New Emergency Spillway. Why?
3D Model simulations of a "flip bucket" & how a spillway flow could "jump a distance".. Concerns in the force vector stresses in anchoring such a design
Citing potential security risks, state and federal officials have blocked the public’s ability to review the latest report from an independent panel of experts brought in to guide state officials’ repairs at the crippled Oroville Dam.
THIS is the DWR letter that triggered the response in a block of the public's ability to review the latest report from the independent panel of experts (functional "security" weakness)
How can the spillway be brought to modern design standards based on spillway design history and other dam failure knowledge gained?
DWR's Project Safety Compliance Report strategy will come back to haunt them