Alberta Flood Watch 2014

[chemgear]

http://www.calgaryherald.com/news/ca...599/story.html

Relief as major southern Alberta flooding fails to materialize

Hundreds of southern Alberta residents were forced from their homes due to overland flooding and sewer backup, and nine communities continued to be under local states of emergency.

But officials have scaled back rainfall and river flow predictions.

[Bigtime]

The new airport tunnel is closed due to flooding.

Edit: Scratch that it is open again.

[You Need a Thneed]

Heavy rain will always have the potential to overwhelm the pumps on the stormwater tank for the tunnel. That's why there are the electronic signs all over, so it can be automatically closed temporarily. Of course, the question is "Why don't they design and build it so it can't do that?" The answer is, the costs would be astronomical. All roads are designed to flood in the heaviest rainfall events.

In this case, "flooding" means a couple of feet at most of water pooling at the low spot, which is very close to the west end of the tunnel.

[Mazrim]

It will only need to be closed for really short periods of time while pumps catch up, I assume. Certainly nothing to be worried about.

[BlackArcher101]

Originally Posted by You Need a Thneed

Heavy rain will always have the potential to overwhelm the pumps on the stormwater tank for the tunnel. That's why there are the electronic signs all over, so it can be automatically closed temporarily. Of course, the question is "Why don't they design and build it so it can't do that?" The answer is, the costs would be astronomical. All roads are designed to flood in the heaviest rainfall events.

In this case, "flooding" means a couple of feet at most of water pooling at the low spot, which is very close to the west end of the tunnel.

Except in this case I believe they designed it (storage and pumps) to handle a much greater rainfall rate than has fallen so far and the pumps should have handled it. Might have been a temporary pump control issue with some kinks being worked out. If I recall, these were just commissioned recently.

[You Need a Thneed]

Originally Posted by BlackArcher101

Except in this case I believe they designed it (storage and pumps) to handle a much greater rainfall rate than has fallen so far and the pumps should have handled it. Might have been a temporary pump control issue with some kinks being worked out. If I recall, these were just commissioned recently.

As long as the volume of water flowing into the tank is bigger than the volume of water getting pumped out, the tank could overflow. There is quite a large area that drains into that stormwater tank. I have no idea about the size of the pumps, but it's not unreasonable to think that a moderate rain for an extended period of time could completely fill the storm tank, meaning extra water would pool in the tunnel.

For the simple fact that the tunnel is sunken into the ground, there is nowhere else to bring the water but to the storage tank, where it can be pumped higher. The drainage areas, for the sake of a visualization, are 400m long and 100m wide on each end of the tunnel, so let's say 80,000 square metres. 10mm of rain falling on that area means that you have 800 cubic metres of rain water to deal with. Obviously, one storm event can bring a lot more than 10mm of rain.

If the tunnel area gets hit with a storm like hit in June 2007, with 75mm in an hour and a half, the tunnel might be flooded with 10 feet or more of water. That rainfall would bring more than a cubic metre of water into the stormwater tank every SECOND.

[BlackArcher101]

Originally Posted by You Need a Thneed

As long as the volume of water flowing into the tank is bigger than the volume of water getting pumped out, the tank could overflow. There is quite a large area that drains into that stormwater tank. I have no idea about the size of the pumps, but it's not unreasonable to think that a moderate rain for an extended period of time could completely fill the storm tank, meaning extra water would pool in the tunnel.

For the simple fact that the tunnel is sunken into the ground, there is nowhere else to bring the water but to the storage tank, where it can be pumped higher. The drainage areas, for the sake of a visualization, are 400m long and 100m wide on each end of the tunnel, so let's say 80,000 square metres. 10mm of rain falling on that area means that you have 800 cubic metres of rain water to deal with. Obviously, one storm event can bring a lot more than 10mm of rain.

If the tunnel area gets hit with a storm like hit in June 2007, with 75mm in an hour and a half, the tunnel might be flooded with 10 feet or more of water. That rainfall would bring more than a cubic metre of water into the stormwater tank every SECOND.

I'll send you a PM to prevent cluttering the thread.

[Acey]

More from Lethbridge County, Raymond, Waterton.

Spoiler!

[Regulator75]

Short Aerial video of high rivers, dam, and some flooding in Southern Alberta, Shot along 22x, Lundberg Falls, and Pincher Creek.

[Raekwon]

OMG, it must be bad, look at those people in a boat.

Originally Posted by Acey

More from Lethbridge County, Raymond, Waterton.

Spoiler!

[Boblobla]

Originally Posted by Raekwon

OMG, it must be bad, look at those people in a boat.

I hope they brought their flippy floppies.

[Roof-Daddy]

^^^ What a disaster.

Thoughts and prayers....

[Acey]

Originally Posted by Raekwon

OMG, it must be bad, look at those people in a boat.

Yeah I don't have great photograhpic evidence of it but I'm quite sure there's lots of people with water filled basements.

[Minnie]

Holy crap, that water at Lundbreck Falls! I saw some artsy pictures on FB yesterday, of Lundbreck, but the photographer didn't show the level of the water upstream nor downstream of the falls.

We stop in there any time we're down south. Love those little falls - when they're little.

[keratosis]

Originally Posted by fotze

My cousin in Lethbridge sent this photo of her backyard.

Spoiler!

How do they cope.
Nobody should have to live with white plastic lawn furniture.

[Bigtime]

Just a reminder of the Sunnyside Flood Appreciation party for volunteers that helped with the clean up last year. 4-7pm tomorrow at the Crisis Cafe site (5th street and 7th avenue NW).

For my CP buddies I have the finest hipster beer, PBR.

[SebC]

Originally Posted by Bigtime

Just a reminder of the Sunnyside Flood Appreciation party for volunteers that helped with the clean up last year. 4-7pm tomorrow at the Crisis Cafe site (5th street and 7th avenue NW).

For my CP buddies I have the finest hipster beer, PBR.

I might stop by.

[Otto-matic]

Originally Posted by Bigtime

Just a reminder of the Sunnyside Flood Appreciation party for volunteers that helped with the clean up last year. 4-7pm tomorrow at the Crisis Cafe site (5th street and 7th avenue NW).

For my CP buddies I have the finest hipster beer, PBR.

See you there tomorrow bigtime!

[surferguy]

I'll be stopping in. Lattes?

[Puppet Guy]

Originally Posted by fotze

My cousin in Lethbridge sent this photo of her backyard.

Spoiler!

that can't be Lethbridge - the wind would've knocked all the chairs over!