MandysMom wrote:Thinking about you Anne!
Velda
Thanks, Velda.
I am kinda in a stew. It is pouring rain here at my house just now (!), with a LOT more on the way over the next few days.
I originally "self-evacuated" when I first heard that water "might" "begin to be released" over the emergency spillway. Why? Because the "emergency spillway" (now conveniently re-named the "auxiliary spillway") was just a. . . hillside (no concrete) from which (get this) they were in process of removing all of the ground cover down to bare dirt so that "trees and bushes would not wash down into the river".
Er. . . this made no sense to me.
1. "released" implies control. There is no control over the water when it begins to flow over the emergency. . . [cough] I mean the "auxiliary" spillway. This "spillway" is comprised of a 30-foot-tall lip of concrete at the top of a hill. When the lake gets full enough - as it did - water begins to flow over this lip, like it or not. Picture a bowl of water. Keep pouring water into the bowl and watch what happens. You get the idea.
2. All of the vegetation that might have "greased the way" for the water coming over this "spillway" was removed (you can see this in the videos). Now, imagine what happens if you go out into the back yard with your garden hose, put your finger on the end, and spray your grass at as high a pressure as you can manage (this would probably be somewhere in the area of 10 cfm - 10 cubic feet per minute). What happens? Not much. The water just rolls off the grass. Now take this same garden hose, with this same method, and spray an empty patch of dirt, and watch how fast the water begins to dig a hole. At only 10 cfm.
The water flow over the emergency, I mean the auxiliary spillway, was 12,000 cubic feet per second. MAGNITUDES greater than the garden hose example. Small wonder that this bare, dirt, hillside eroded. BIG surprise that! [not]
When it was announced that the water "might" come over the auxiliary spillway, armed with what I know about water and erosion, I left. I went to the San Francisco area and stayed with friends. The next morning (after I had left) water began to come over this emergency/auxiliary spillway - even though, as late as the day before, they were predicting that it would not.
This flowed all day (seemingly) without problem, all the while DWR (California Department of Water Resources) sending out regular bulletins that "everything was working as it was designed to work, no problems, no worries".
So, I thought (since I am a glass half-empty kind of person, rather than a glass half-full kind of person) I would just go back home (after being gone for about two days). So I'm thinking (sometimes it doesn't pay to think, one should just go with their gut) what the hell do I know? If DWR says things are fine, then they are fine, right? RIGHT???
So I loaded up my van, and drove the two hours home. When I got home I was pretty beat, threw all of my laundry into the washing machine, and stuck dinner in the oven. While dinner was cooking, I unloaded my van. I wasn't even going to turn on tv, I mean I had the straight scoop, right?? But I did anyway - I dialed up my Roku box to the Weather Underground channel. There found a clickable "flood notice" warning. Ho-hum. This notice had been on this website for more than a week, so I decided not to even click on it, and just go to bed.
Clicked on it anyway: "Imminent partial dam failure expected within the next 45 minutes. Evacuate Immediately. This is NOT a drill. This is NOT a drill. This is NOT a drill". So much for advance warning!
Did this get my attention? Well, yes and no. I was completely exhausted, this didn't seem real, I was beginning to feel a bit shocked by the whole adventure and I wondered if it was a hoax. So I called my friend (whose home I had just left) in the Bay Area to try to get a grip on [un]reality. She said to get packed, and that she would go online and see what was what. She, too, thought it might be a hoax.
I started throwing everything that I had just unpacked back into the van as fast as I could. Didn't take long. Families all up and down my block were outside throwing stuff in their cars just as fast as they could. Just as I was sitting down on the couch to take a breath, my friend called back: "Get the Hell out NOW!!" It didn't take any further encouragement. I walked out my front door, keys in hand, started my van and drove away. Everyone else on my block was still packing - it was a bit of a blessing that I had already self-evacuated once already - so I didn't need to sort and choose what (and what not) to bring.
I drove west out of town, which took about 15 minutes, instead of the usual 5, until I came to my favorite turn-off and turned south. I beat the horrible traffic and terrible congestion (that I later saw on tv) that probably happened only a few minutes later, had I not gone when my friend called. I had a few "iffy" spots to get over - namely, the Sutter Bypass and Knights Landing - but since I had passed this way just a little more than an hour before, I felt confident that they would be safe. They were fine.
After two more days at my friend's house (THANKYOUTHANKYOUTHANKYOU J & S!!!) the "mandatory" evacuation was lifted, but a "provisional" evacuation still remains in place. I interpret this to mean "Go home and get your stuff together, remain vigilant, and be ready to leave again on a moment's notice."
Which I am doing. I have a friend of a friend (is this how rumors get started?) that says someone close works for DWR. Allegedly, the word on the street from this person is that if the level of the Feather River at Yuba City reaches about 70 - 75 feet (flood stage is 80 feet) or if water begins to again flow over the emergency/auxiliary spillway at Oroville dam. . . to just leave, and not wait for evacuation orders.
Which I will do - in fact, I am doing all my laundry and re-packing my van even as I type (multi-tasking!!)
What with all of the hullabaloo, there has been very little mention of the still-damaged, and still-flowing concrete (well, concrete-and-dirt just now) primary spillway. There is something that looks like an access road, or access area to the right side of this spillway, when looking at the spillway from the bottom to the top. If one looks at the videos, and still photos (YouTube), it appears that the initial breach in the concrete, which occurred several days ago, happened more or less opposite this access area. If one looks at video and still photos from yesterday (after many days of 100,000 cfs water release down this spillway) and compares these photos and videos to those from several days ago. . . it appears that the spillway is not only eroding downstream from the break, but it is eroding upstream (towards the flood gates) as well. Note that in the original press releases regarding this damage, it was stated that "the breach is approximately 2/3 of the way down the spillway, near the bottom".
It appears that this might no longer be the case. The most current photos and videos seem to indicate that the breach continues to erode upstream (again, towards the flood gates) and now appears to be about 1/2 way down the spillway, instead of 2/3 down the spillway.
Are these indications accurate? I don't know. It is difficult to estimate the rate of uphill erosion from photos and videos taken from different angles.
Bottom line: if the erosion - of the concrete - reaches the spillway gates, or even near to the spillway gates. . . all bets are off.
Historically, March can be the wettest month in my area. There is - currently - a massive snowpack in the Sierra, much of which is drainage into the Oroville dam watershed. When a warm storm arrives, with rain on the snowpack (instead of more snow) the snowpack will begin to melt.
This can happen slowly, and it can also happen all at once. This was one of the main reasons for the massive flooding that happened in my area in 1997 (check YouTube for Marysville Flood 1997). Which, by the way, almost - I say, almost - also over-topped the emergency spillway at Oroville dam (there was about 12 inches remaining before the flow would have begun).
What happened in 1997 is that there was a large snowpack in the Sierra in the Oroville dam watershed. A massive sub-tropical (as opposed to arctic) WARM storm came through that was called, at the time, the "Pineapple Express" (one doesn't forget these things).
The entire snowpack melted within a few days, with a massive amount of snowmelt running down into Oroville dam.
Today is a warm storm, and it is currently pelting with rain at my house. Tomorrow's storm, and the storms for the rest of the week, are predicted to be colder.
I pray that it might be so.
Anne
