Need a way to stay awake at night? Try an inundation map

If you’re trying to keep yourself awake at night and that Stephen King novel isn’t doing the trick, you could always take a gander at a Lake Oroville inundation map.

You may have some trouble finding an official one. But there’s an unofficial map with some interactive features that gives you a view of what might happen should the emergency spillway give out, as was feared would be the case before the Feb. 12 evacuation orders were given for Butte, Sutter and Yuba county residents.

If you like being worried, here’s all the fodder you need (unless it turns out you’re in one of the high-and-dry spots).

We ran a story about the map created by graduate students at the UC Irvine Department of Civil and Environmental Engineering. As maps go, this one is fairly sophisticated – based on a study by the graduate program, it shows how the areas downhill from the Oroville Dam would be affected if that emergency spillway were to have been knocked out and a wall of water spilled out.

We were warned in the story that it’s not an official document and can’t, therefore, be used in actual emergency planning. At the same time, no one was telling us it was wrong.

Had that spillway failed, about 451,830 acre-feet of water would have flooded the valley. The goal of the grad students’ program was to show how these sorts of projects could present data and could be used in planning – for emergencies and for risk mitigation. It’s considered to be from 60 to 80 percent accurate ... still, it’s not supposed to be officially utilized.

The unofficial inundation map can be viewed at tinyurl.com/lk6de7u. When you go to the website, you have to check a box to acknowledge “that this information is for educational purposes only and that I will not use the information depicted for legal, engineering, surveying, or official planning.”

Once you’re in, you can toggle elements to get different information, but here’s the legend that catches our attention: “Intensity of Flowing Water.” The range starts at “People Likely Stable” to “People Toppled” to “Cars Displaced” to “Structural Home Damage” to “Homes Washed Away.” Fields of color show the different levels.

If you’re in Live Oak, you probably will be able to keep your footing. If you’re in Sutter, you don’t have a lot to worry about, according to this graphic. There are parts of Yuba City and Marysville that would be seriously affected – homes gone. Linda would be OK.

What’s the real value of this map? Perhaps in making it more apparent to officials what could happen. And to make more apparent to area residents that there are real risks to be evaluated.

In informal surveys we took, some 30 percent of respondents said they didn’t bother evacuating during the Feb. 12 crisis. We’re figuring the sort of people who take these sorts of surveys are probably more prone to follow directions ... so those who ignored the evacuation order, perhaps, were less likely to participate in a survey. So the percentage of people who didn’t evacuate, we theorize, is considerably north of 30 percent. That’s a big bunch of people who didn’t bother trying to get out of the way of what could have been a killer flood, as depicted (theoretically) by this map. And then there were the thousands of people who came back to the dangerous areas well before the evacuation was lifted.

Our advice is to not let the map worry you over much – it seems to us that things are now in hand. Still, it doesn’t hurt to see what the possibilities are; you might decide to evacuate the next time.

Just maybe don’t look it over at bedtime.