Follow-up tweets from @RyanMaue regarding the volume of rainfall coming... it’s actually frightening:
> Assume 6” of precipitation across 3950 sq mile across Lake Oroville catchment area (Feather River) = 400 Billion gallons of liquid input.
> Lake Oroville holds 1.15 Trillion gallons — so 0.4 Trillion gallons rainfall = 1/3 of capacity on the way [assuming no outflow]
Even if HALF of that ends up being correct, I can’t see how that dam doesn’t over-top all together.
Can they drop the lake 30% of capacity before the rains begin?
For the next 4 days, output from Oroville should be between 100k cfps and 140k. Predicted inflow at the height of the storm should be 220k cfps.
So for every hour between now and the large inflows, that’s an hour extra the dam can handle the inflow.
There were a number of considerations at Oroville; they wanted to see how the emergency spillway handled. They found out that it just wasn’t set up to handle much of anything, and returned to using the damaged spillway. They are repairing the emergency spillway just in case it has to be used again.
They also wanted to reduce the outflow to protect river fish from silt (?!?!?!?!?!??) but the people wearing big boy pants now appear to be in charge of Oroville and are managing the water and letting other agencies manage their things as they can.
Alan, thanks for the caculations.
Throw in some large snow melts to really complicate this life and death zigsaw puzzle.