i'm sure we have all seen about the dam overflow and just now I read that the roads are jammed by people fleeing town.
if anyone asks if a BOB is a silly thing to have ready show
them this.

If you live downstream from a dam you should have a plan and a BOB. The path of a hugely destructive dam failure is just an easy bike ride from me:

https://en.wikipedia.org/wiki/St._Francis_Dam

Pictures of the destruction are very sobering....

I'm downstream from a dam. How do I prep for this? It seems like perhaps I need to figure out whether my house will be flooded, and which roads will be flooded (so I can plan my escape). How would I do this? I know topographical maps exist, but I wouldn't know how to estimate flood trajectory and inundation level.

Hi,
you shouldn't need to do any flood estimations,
your local government, dam/city/county/state/country,
should have published inundation maps specific to dams,
there should also be some evacuation plans,
...
years back I checked and if I recall correctly
hazards.fema.gov
didn't have dam data
...
I watched the tv news report on the hole opening ,
two people hiking and called it in,
stayed to watch, and then for the interview,
...
I thought it was a good time to pack and review/check plans,
...
then later the hole is reported as 200 foot
...
I thought a good time to inquire about hotel reservations
and check road conditions with google and other sites
...
naturally the tv news just marveled at the spectacle,
until the evacuation was called no real thoughts of preparation were hinted at, only the potential for disaster , fear sells
...
after catching that on the news, I either read or heard about a resident new to the area returning a reverse 911 call to ask for driving directions to a hotel,
...
I thought whoa, I would never think of that ...
then a minute later I remembered I'm exausted and sleepy
but despite that , stop/think/observe/plan, it works
...
regarding road conditions, I checked for highway flooding for the first time last week, spent a good half hour trying to decide if the hazard report meant the highway was blocked or just the exit that was flooded,
and no I wasn't sleepy then

188,000 people evacuated and Oroville dam was expected to fail.
Interesting article, it reads like an ongoing situation summary. Apparently the dam had been expected to fail, possibly losing 30' (vertical) of spillway which would have put towns downstream underwater. However... Read more here: http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html

There's another good read at: http://www.sacbee.com/news/state/california/water-and-drought/article132356269.html

My local county has an official "hazards map" which lists and maps areas subject to severe earthquake shaking,liquifaction zones (also EQ related), 100 year and 500 year flood areas, regions subject to tsunami inundation, and similar goodies.

In most jurisdictions, I believe there is a requirement to inform prospective buyers if the land is within a 100 year flood zone

Latest update: Oroville Dam Evacuations: Here Are The Latest Updates

I'm coming across accounts that point that many if not most people were taken by surprise when immediate mandatory evacuation order was given. Apparently many folks put their family into the car and took off with what they were wearing, carrying, and whatever they had in their vehicle.

Anybody else picking up on this?

One of the things I had to sign when buying my house was an acknowledgment of assessed hazards (earthquakes, fires, floods, aviation, etc.).

Laat night, I watched a live Youtube feed that a person was re-streaming from a local TV news station (KRCR.)

Interesting to see events in real time and a the sharp contrast of how the news was being presented earlier today (lots of misinformation but that is perhaps another discussion later.)

During the live feed, they had a reporter who was on scene of a very busy gas station. It would come as no surprise to members here, that the people affected were not prepared in any way and were waiting for substantial amounts of time to fuel their vehicles before leaving the area.

That's almost cliché. During any large evacuation, there will be lines at ATMs and gas stations around the evacuation zone.

Getting extra cash and gas is usually one of my first step when preparing for a possible emergency. If I need it, great. If I don't need it, I won't need to visit the ATM for a while.

Keeping the lower half of my gas tank for emergencies means I can drive 150+ miles before I need to fill the tank. "Don't stop at the top of the escalator."

IMO, It's not cliche, more like unprepared. This dam has been in declining condition all week and I first seen the reports on the 7th. By the 9th, the problems were with the dam were widely reported but it was not until this weekend that the danger was raised to imminent and the reason for the evacuation.

I am sure there will be a lot of armchair quarterbacking on why the call for evac was not done sooner etc. However the fact that the dam had sustained damage earlier in the week, would have been cause for me to start preparing then and not wait until the last minute which is all too often the case for those without a preparedness mindset- no matter the disaster.

BTW, my early interest in this dam and evac is because we have old friends in that area, but they are upstream and in no danger.

Exactly. We store anywhere from 20-30 gallons of gas. In theory and in the event of an evac, with the truck tank full at 32 gallons and 30 gallons in Jerry cans, this gives a range of over a thousand miles.

To put this in perspective. If we were in the Oroville CA area and depending on traffic etc, we could drive without refueling to any of these major USA centers without a refueling.
Seattle WA
Denver CO
Phoenix AR
Albuquerque NM
Jackson Wy
Boise ID

Needless to say it would take an unheard of and massive western regional disaster event where in a 1000-1200 mile range, that one could not find fuel.

Living in earthquake country, I try to never drop below one half tank. And that is in a case where my preference would be to bug in if there should be a damaging shaker.

I doubt you would need much fuel to get beyond the confines of the watershed affected by the Oroville situation. Just be sure you sleep high.

Wildman and others..yes and we saw the photos of the bashed up cars,a lot of panic there.without making a joke out of this it must of been like a scene from a old movie where the guy runs
down main street shouting "the dam busting head for the hills"
I get the impression that it was the same thing.people were given the impression that at any moment the spillway was going to fail when from the looks of the guys in the yellow jackets standing around that was not the case.
another thing is the car wrecks.even if you were all prepped up
and on the way to you planned safe area how about the next guy who is driving like a fool.did the police have a traffic control
plan? just think about it will be like when the Big One hits.
I hope someone holds some "lessons learned" meetings.

Looks like the dam disaster threat is over (for now.)

California Residents Allowed to Return Home After Dam Spurs Evacuation

Evacuations lifted for communities below Oroville Dam

I wonder:

Will anyone prep up in the event these rain predictions create an even more serious repeat of a no notice evacuation?

Will anyone decide never to be caught in such a situation totally unprepared, again?

Is anyone going to be suspicious of what their state agencies release to the public, and how warnings are worded?

It sounds like the danger isn't past, but it's down below panic levels. If I were in that situation, I would seriously consider packing up my household and re-evacuating to higher ground until the evacuation warning was lifted

Wild, if just half of the people do something in the way of prep that would be a plus coming out of this mess.
even if folks 100's miles away are encouraged to set a box of food and water aside that would be something.
from what i read about that local town it sounds like things are not going very well.spending for emergency gear might be out of reach and i'll bet it's like that for more people than we think.

Strangely appropriate timing that this would appear on my news feed, but the 21 Mile dam in Elko NV collapsed last week. No mention of fatalities, but it looks like it took a good chunk of the infrastructure with it when it collapsed.


https://lasvegassun.com/news/2017/feb/09/elko-county-declares-emergency-after-earthen-dam-f/