Flood Review

seewood
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Re: Flood Review

Post by seewood »

andrea-lake wrote:However, the authorities are still taking a gamble on how high the lake could rise if we get a wet spring and/or if the freshet happens too quickly. They don’t build enough of a contingency for unexpected weather in addition to a higher than normal snowpack. As Brentville points out, the weather is unpredictable. Consequently, they should begin to increase the rate of drawdown earlier and follow the 1974 standards based on 80+ years of historical experience. That is the judgement we should be relying on, and these rules were re-affirmed in the 1998 flood review.


From observations while walking the dogs over the dam and down the channel the past month or so, All I can say, I really don't know how much more the dam could be opened and increase the flow. We all know the channel was engineered for a max flow volume, which was exceeded last year for some time. Currently the channel is pretty high.
Also, I really don't know about the down stream lakes, dam flows and the flows into the US. Me thinks this emptying of the lake is so much more than just opening the dams and be damb'd of those downstream well into the US.
If it is a slow melt or even with this week of warm weather, I don't think we will have too much of an issue with really high water. If a moisture laden storm hits us right after this warm weather, the lake will fill much like last year. Drain too much and then it goes dry for the next 5 months or so, 2003 was like that, there will be complaints the lake is too low...
Last edited by ferri on Apr 24th, 2018, 9:56 am, edited 1 time in total.
Reason: Fixed quote (I think...)
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Glacier
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Re: Flood Review

Post by Glacier »

Flows into the US are no concern. The Okanagan river is a lot smaller than the Similkameen, so they don't really care about the Okanagan that much. The gates are wide open at Osoyoos Lake right now.
andrea-lake
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Re: Flood Review

Post by andrea-lake »

I agree with seewood that we don't want increased flood risk downstream, but the lake managers can reduce everyone's risk by keeping the lake lower so storage doesn't become a critical issue. Below is a concluding quote from the Okanagan Lake Water Level Management Review of Past Trends with Recommendations Final Report March 2000:

“Presently the lake is operated most of the time at elevations that are higher than may be necessary. This creates problems for fisheries during high runoff years because of the need for extensive lowering of the lake during the winter months".

The statement by Sean Reimer in Castanet today shows why they need a higher contingency factor to deal with the unexpected:
“We are currently discharging about a centimetre and half of water on the lake per day, so that based on the April to July forecast of the amount of water expected to come in, it should be managable.” That doesn't take into account wet weather in the valley bottom or if the water comes down very quickly, like last year. “That can become very problematic,” he said.
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alanjh595
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Re: Flood Review

Post by alanjh595 »

I am wondering......since they have lowered the lake, reduced the back pressure caused by the lake water, removed the natural restrictions and all of those that were caused by the accumulation of human influence (shopping carts, lumber, junk) from the creek in an effort to improve flow rate.......
Would this not only make the run faster, but also increase the likelihood of undermining by the rushing waters? The creek might not overflow, but it could cause erosion damages too.
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andrea-lake
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Re: Flood Review

Post by andrea-lake »

Mission Creek is going to rise fast now

We're all aware that the first big melt will start this week. Mission Creek has already risen from 6 cubic meters per second to 20 m3/s and is expected to spike up to 60 m3/s by May 1st. Water levels in the creek are expected to rise by about 1 meter, based on what happened with a similar flow last year.

You can see the official forecast of Mission Creek by the BC River Forecast Centre at the link below. Keep in mind it's revised daily and can change substantially.
http://bcrfc.env.gov.bc.ca/freshet/clever/08NM116.PDF

For those who want to compare the current Mission Creek forecast with what happened last year, see my post on "Snowpack and Stream Data" at this link:
viewtopic.php?f=119&t=77973
dominik
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Re: Flood Review

Post by dominik »

andrea-lake wrote:Mission Creek is going to rise fast now

We're all aware that the first big melt will start this week. Mission Creek has already risen from 6 cubic meters per second to 20 m3/s and is expected to spike up to 60 m3/s by May 1st. Water levels in the creek are expected to rise by about 1 meter, based on what happened with a similar flow last year.

You can see the official forecast of Mission Creek by the BC River Forecast Centre at the link below. Keep in mind it's revised daily and can change substantially.
http://bcrfc.env.gov.bc.ca/freshet/clever/08NM116.PDF

For those who want to compare the current Mission Creek forecast with what happened last year, see my post on "Snowpack and Stream Data" at this link:
viewtopic.php?f=119&t=77973


Yep, alone the difference between the day before yesterday and yesterday is quite noticeable down stream. I had to do a double take when I came from McCulloch down to Gordon...
andrea-lake
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Re: Flood Review

Post by andrea-lake »

Hopefully the Regional District will issue a bulletin soon to alert people living near Mission Creek about the fast rise expected.
seewood
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Re: Flood Review

Post by seewood »

The temps at night are still cold. Especially at the current snow line. I suspect there will be quite the flow around 4-6 pm after the warm day melts but once the sun goes down and no cloud cover, the temp drops slowing the melt.
Now saying that, I believe the area is expecting rain on Sat. and Sunday.
That is what will really get the water moving as it warms up at night and if rain continues, the streams are going to be moving and the lake filling back up.

More issues for the jurisdictions to deal with regardless. The continual ground slumping episodes just compound the need for resources.
Want a fear mongering statement? perhaps taxes will go up to pay for all this.
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alanjh595
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Re: Flood Review

Post by alanjh595 »

Capture.JPG


Today Sunny. High 26. UV index 8 or very high.
Tonight Clear. Becoming partly cloudy overnight. Low 6.

Sat, 28 Apr Becoming cloudy in the morning with 40 percent chance of showers in the afternoon.
Wind becoming south 20 km/h in the afternoon. High 18.
Night Cloudy with 60 percent chance of showers. Low 9.

https://weather.gc.ca/city/pages/bc-48_metric_e.html
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JoeS
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Re: Flood Review

Post by JoeS »

So with all this warm weather where is the full lake?

probably doesnt help that they have increased the discharge rate at the dam as per that website

the people that complain and worry about the flooding know that we are not what was referred to when they where talking about "draining the swap" right?
glad all this old past data is helping us over react and justify "forecasting" the lake level
again, where was all this 'what if' data last year?
mother nature may not strike us twice in a row but human error sure looks like its going to :130:
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Glacier
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Re: Flood Review

Post by Glacier »

Coldstream creek is flowing at a faster rate than it was at this time last year. In fact, the volume has increased 2000% since the beginning of April and is currently higher than it was at this time last year! Houses are being flooded as we speak. Well, not houses, but properties. Out buildings that flood most years kinda things.

Coldstreamcr.png
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Fancy
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Re: Flood Review

Post by Fancy »

JoeS wrote:So with all this warm weather where is the full lake?

It's rising.
Image
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Glacier
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Re: Flood Review

Post by Glacier »

Your link doesn't work
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Fancy
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Re: Flood Review

Post by Fancy »

I didn't post a link because it has been posted numerous times but here you go:

https://wateroffice.ec.gc.ca/report/rea ... tn=08NM083
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JoeS
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Re: Flood Review

Post by JoeS »

Fancy wrote:
JoeS wrote:So with all this warm weather where is the full lake?

It's rising.
Image

over 2 days sure
still way low for the month
its even a LOT lower then this year last time
and the dam rate is still higher then it was at this year last time. over all lake level is still dropping. one station shows a 2 day spike by a run off area

lets crank the dump rate :panic:

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