Analysis of the Flood

[dirkterrell]

It was a 1000-year event for many areas according to NOAA (meaning that the odds of such a flood are 1 in 1000 in any given year). Check out Figure 4 here:

http://www.nws.noaa.gov/oh/hdsc/aep_storm_analysis/8_Colorado_2013.pdf

[50sGrl]

Which does NOT mean that it will be another 1000 years before it happens again.

[dirkterrell]

Which does NOT mean that it will be another 1000 years before it happens again.

Yes, it is a statistical concept, not a periodic one, hence my parenthetical comment in the first post.

[madvlad]

Wonder if this means a massive blizzard is up this year :roll:

[big_sur]

Wonder if this means a massive blizzard is up this year :roll:

The farmer's almanac said it's supposed to be much snowier than usual for what it's worth. One can only hope :santa:

[madvlad]

That sucks...

[mdub]

My personal observation in past. If it is cold on holloween it will be a tough winter.

[TFOGGuys]

Something to think about: 10 inches of snow has roughly the same amount of water as 1 inch of rain. Parts of the front range received north of 17 inches of rain in a 7 day period. 170 inches of snow is a little over 14 feet. Be thankful it wasn't 35 degrees cooler.

[asp_125]

Wonder if this means a massive blizzard is up this year :roll:

That reminds me.. must buy ski passes soon. ;)

[One-ops]

Haven't seen a bad winter here in a long time.

[mdub]

Haven't seen a bad winter here in a long time.

yeah 6yrs is a long time


http://i1230.photobucket.com/albums/ee491/walkermi/ph-10453_zps28d56a8c.jpg

[Wrider]

One or two decent storms != a bad year...

[3point5]

Yes, it is a statistical concept, not a periodic one, hence my parenthetical comment in the first post.

Dirk,
youre exactly backwards here - it is a periodical concept, it is something that has repeated cycles. a 100year storm is one that has the intensity and the duration such that it is classified as a storm event that will happen once every 100 years. There are many storms that pour that hard but not as long and vice versa, many storms that last as long but not close to that intensity of rainfall.

If you know what to look for in a area detention pond, you can gauge a storm by how close the water gets the the 'emergency spillway'. Not always, but a 'modern' detention pond is designed to hold the capacity of a 100 year storm before the water reaches the elevation of the emergency spillway and overflows.

[DriverDave]

Speaking of holding water...I'm surprised I haven't heard anything in the news about Bear Creek Lake. I work for the Corps of Engineers and Bear Creek is one of my dams. It is currently over 46 feet above normal and still rising. Don't worry, it's doing a fine job of holding all that water (that's what it was built for, after all). It is going to shatter the previous record from 1995 by about 20 feet. Anyone familiar with that area should try to get a look at it in the next week or so...it's almost the size of Chatfield now!

[longrider]

Speaking of holding water...I'm surprised I haven't heard anything in the news about Bear Creek Lake. I work for the Corps of Engineers and Bear Creek is one of my dams. It is currently over 46 feet above normal and still rising. Don't worry, it's doing a fine job of holding all that water (that's what it was built for, after all). It is going to shatter the previous record from 1995 by about 20 feet. Anyone familiar with that area should try to get a look at it in the next week or so...it's almost the size of Chatfield now!

I wish you had posted this in the morning!! :) ;) I was just there this afternoon (285/470) and had I known I would have checked it out. From your size description I would assume most of the park and road/trail system is flooded?

[dirkterrell]

Dirk,
youre exactly backwards here - it is a periodical concept, it is something that has repeated cycles. a 100year storm is one that has the intensity and the duration such that it is classified as a storm event that will happen once every 100 years.

No, that is a common misconception and the main reason why the USGS has moved away from using that terminology. See this:

http://pubs.usgs.gov/gip/106/pdf/100-year-flood_041210web.pdf

and note the middle panel:



Consider the following: if we had 1,000 years of streamflow data, we would expect to see about 10 floods of equal or greater magnitude than the “100-year flood.” These floods would not occur at 100-year intervals. In one part of the 1,000-year record it could be 15 or fewer years between “100-year floods,” whereas in other parts, it could be 150 or more years between “100-year floods.”

[FZRguy]

Bear Creek Lake on Tuesday where the bike path meets the lake. Flood control worked as designed here.

https://scontent-a.xx.fbcdn.net/hphotos-ash3/580303_537158283027362_1723660384_n.jpg

[madvlad]

yeah 6yrs is a long time


http://i1230.photobucket.com/albums/ee491/walkermi/ph-10453_zps28d56a8c.jpg

I remember that one, at our place the snow was almost covering the whole front door and the garage doors, had to jump out the 2nd story window and start cleaning snow from the outside in. It was horrible plus thankfully our neighbor had a lifted F350 that hauled us all to the local king soopers cause nobody else could get out lol

[rforsythe]

For reference, here is a list of the worst blizzards in Denver (they say Colorado, but the article seems to forget there are places in CO that aren't Denver...anyway):
http://blogs.denverpost.com/library/2012/02/02/a-list-of-colorados-historic-blizzards-and-snowstorms/367/

We lived in Elbert County in 1982, and got a hell of a lot more than two feet that Denver saw. They had to use front loaders to clear enough road for one lane to get to us, we were snowed in for days, and it was up to 12 feet in places. We had a lower level on the house with a garage, and I can remember the snow coming up to the second floor on that side of the house.