Monitoring lake level to prevent flood

andrea-lake
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Re: Monitoring lake level to prevent flood

Post by andrea-lake »

Glacier wrote:There hasn't been any flooding on Okanagan Lake that I know of. The lake has peaked at the 1 in 5 level, which is not flood stage. The lakes that did get serious flooding were downstream, namely Osoyoos Lake. If the selfish Kelownites got there way, there would be even more flooding on Osoyoos Lake. Thankfully, the operators knew what they were doing, and didn't flood Osoyoos more than they had to.

No selfish Kelownites here…

The Rules from the Canada-British Columbia Okanagan Basin Agreement balanced the interests of all parties as outlined in the Symonds (2000) report. http://www.obwb.ca/obwrid/docs/023_2000 ... n_Lake.pdf

Glacier, you missed my whole point. I started out by saying the lake is NOT flooding so why did we have to incur the needless expense preparing for a non-event? The answer is simple – the Lake Managers did not follow the Rules in February and March of 2018. If they had, the lake would have been drawn down sufficiently in March to save everyone from the threat of a flood that didn’t happen. It would also have given them room to reduce the outflow at a critical time to alleviate the Osoyoos flooding.
Last edited by andrea-lake on May 28th, 2018, 1:46 pm, edited 1 time in total.
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Glacier
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Re: Monitoring lake level to prevent flood

Post by Glacier »

andrea-lake wrote: No selfish Kelownites here…

The Rules from the Canada-British Columbia Okanagan Basin Agreement balanced the interests of all parties as outlined in the Symonds (2000) report. http://www.obwb.ca/obwrid/docs/023_2000 ... n_Lake.pdf

Glacier, you missed my whole point. I started out by saying the lake is NOT flooding so why did we have to incur the needless expense preparing for a non-event? The answer is simple – the lake managers did not follow the rules. If they had, the lake would have been drawn down sufficiently in March and early April to save everyone from the threat of a flood that didn’t happen. It would also have given them room to reduce the outflow at a critical time to alleviate the Osoyoos flooding.

That link is almost 20 years old. Perhaps their standards have changed since then. I mean, as we know, even the simple data about how high the lake level is versus previous years is contradicted depending on which year the article was written.

Also, you can still get flooding by following the rules outlined in that link. Look at last year.
andrea-lake
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Joined: Mar 18th, 2018, 12:58 pm

Re: Monitoring lake level to prevent flood

Post by andrea-lake »

Glacier wrote:
andrea-lake wrote: No selfish Kelownites here…

The Rules from the Canada-British Columbia Okanagan Basin Agreement balanced the interests of all parties as outlined in the Symonds (2000) report. http://www.obwb.ca/obwrid/docs/023_2000 ... n_Lake.pdf

Glacier, you missed my whole point. I started out by saying the lake is NOT flooding so why did we have to incur the needless expense preparing for a non-event? The answer is simple – the lake managers did not follow the rules. If they had, the lake would have been drawn down sufficiently in March and early April to save everyone from the threat of a flood that didn’t happen. It would also have given them room to reduce the outflow at a critical time to alleviate the Osoyoos flooding.

Glacier replied: "That link is almost 20 years old. Perhaps their standards have changed since then. I mean, as we know, even the simple data about how high the lake level is versus previous years is contradicted depending on which year the article was written.

Also, you can still get flooding by following the rules outlined in that link. Look at last year"


Glacier, you raised the issue of how valid are the Rules summarized in the Symonds (2000) report. On page 4-1 of Brian Guy's 2017 Flood Review report, he clearly states that this summary of the Rules is still valid. Refer to the excerpt below.
Symonds pic 1.jpg

Below is Brian Guy’s reference on Mr. Symonds who was called back from retirement to handle the flood emergency at the most critical period during 2017. It Mr. Symonds who confirmed that the dam outflow could be increased beyond 60 m3/sec to 75 m3/sec for short periods to alleviate the severe flooding last year.
Symonds pic 2.jpg

You also stated that the Rules were followed but did not prevent last year's flood. However, this is not quite accurate. In his 2017 Flood Review report, Brian Guy stated that the Rules were followed (arguably) in February and March, but he did not state that they were followed in April. Based on the River Forecast Center inflow data for April of 2017 and the actual lake level vx target lake level, it's clear they did not follow the Rules. They should have had maximum outflow ALL of April. They only started increasing it to the maximum at the end of that month. Under the Rules, they did not have the discretion to limit the outflow for fish scour prevention at that time. Brian Guy credited the water manager with increasing the outflow in late April despite pressure from the fish biologists who wanted to save more eggs, but he failed to note that the water manager should have actually had maximum outflow from at least the beginning of the month.
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Glacier
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Re: Monitoring lake level to prevent flood

Post by Glacier »

But you have to plan for worst case. It's been dry, but nothing like Atlin which has only had 2mm of precipitation in the past two months. If you have to plan for the case where Kelowna gets no rain for two or three months.
andrea-lake
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Re: Monitoring lake level to prevent flood

Post by andrea-lake »

Glacier wrote:But you have to plan for worst case. It's been dry, but nothing like Atlin which has only had 2mm of precipitation in the past two months. If you have to plan for the case where Kelowna gets no rain for two or three months.

Yes, and the Rules summarized in the Symonds (2000) report provide for worst case scenarios in both flood and drought situations. You mentioned needing to prepare for a few dry months and in fact, the Rules go even further. They deal with back-to-back drought years. Below is an excerpt from page 7 of that report.

Symonds pic 3.JPG
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andrea-lake
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Re: Monitoring lake level to prevent flood

Post by andrea-lake »

In my previous post, I said:

"Brian Guy credited the water manager with increasing the outflow in late April despite pressure from the fish biologists who wanted to save more eggs, but he failed to note that the Water Manager should have actually had maximum outflow from at least the beginning of the month".

Just to clarify, according to Brian Guy's report, the Water Manager is subject to the direction of the Minister of Forests, Lands, Natural Resource Operations and Rural Development (FLNRORD). Therefore, while he can be credited with some degree of push back in April 2017 against the fish biologists who wanted to keep the outflow at Penticton Dam at lower levels until early May, he had limited ability to over-ride the Ministry. Under the Rules, based on the official River Forecast Center (RFC) forecast at the beginning of April, the target lake level was 341.4 meters for the end of the month. Because of the decision to keep outflows low until April 24th and then only to increase them marginally until April 29th, the lake ended up at 68 cm above target. This fact was buried in Brian Guy's report, in his comments praising the Water Manager for his push back. However, even if the outflows had been flat out all during April, the lake still would have been 50 cm above target due to how it was managed in February and March.

For some reason, the Ministry wanted to keep the lake at higher than normal levels during February, March and April in 2017. For example, Brian Guy points out that in February the lake was 11 cm higher than even the fish biologist team (FWMT) model was recommending. More importantly, it was 21 cm above the Lake Operating Rules target for that time. Based on the official input from the RFC, the Rules required them to increase the outflow significantly to bring the lake down to the target level of 341.54 meters in February. They did not do that and the lake remained over 20 cm above target in February. If the lake had been at the target level at the end of February, the Rules would have allowed them to let the lake rise based on the RFC forecast in March. However, the Water Manager suspected the RFC forecast was too low and he knew the lake was already too high. The normal target for the end of March is 341.49 meters so he decided to increase the outflow slightly but the lake was still 26 cm higher than it should have been given the circumstances.

They made a reasonable judgement in March but they were carrying a cumulative error from February that was not corrected in March. Added to the 25 cm error in April due to not following the Lake Operating Rules, and the result was a total of 50 cm of opportunity cost. This means they would not have averted the flood, but the peak would have been 342.75 meters instead of 343.25 meters. Furthermore, had they not been constrained by the Ministry's fish biologists in March, they could have saved the lake from rising by another 25 cm, for a peak of 342.5 meters, which is close to Full Pool.

This is not a case of hindsight being 20/20. It is a statement of how the Lake Operating Rules should have been interpreted without over-emphasis on fishery goals. Brian Guy mentions in his introduction that the lake is managed today in a new way with emphasis on "instream flow needs", i.e. fishery needs. However, he states in his report that the original Rules still govern the lake management and he does not reference any legislation supporting a new interpretation.
andrea-lake
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Re: Monitoring lake level to prevent flood

Post by andrea-lake »

Broad guiding principles for lake management

Previously I’ve posted a lot of detail about the Lake Operating Rules but for those who prefer to see the big picture as opposed to the technical details, following is a summary of the principles embedded within the Canada-British Columbia Basin Agreement as presented in the Symonds (2000) Report, (see link below) and confirmed in Brian Guy’s 2017 Flood Review Report as the current operating agreement.
http://www.obwb.ca/obwrid/docs/023_2000 ... n_Lake.pdf

Symonds pic 4 May 29.png

These Rules evolved from 30 years’ collaboration among stakeholders after very thorough examination of the issues affecting all parties and are based on decades of operational experience. The major steps in the process were:

1969 - Canada-British Columbia Okanagan Basin Agreement funded a formal analysis to be done
1970’s – Comprehensive analysis was undertaken, to create a framework and official Plan
1974 - Canada-British Columbia Consultative Board published the official Plan with Rules on operating the lake, that were developed to achieve a balance among the stakeholders
1976 – Okanagan Lake Implementation Agreement was signed
1976 to 1982 – Engineering work outlined in the Plan was undertaken
1982 – Okanagan Basin Implementation Board issued final report with the Lake Operating Rules
2000 – Okanagan Lake Water Level Management Review of Past Trends with Recommendations (basically confirming the 1974 Rules)
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andrea-lake
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Joined: Mar 18th, 2018, 12:58 pm

Re: Monitoring lake level to prevent flood

Post by andrea-lake »

We dodged a bullet - but still incurred the costs

According to Shaun Reimer we dodged a bullet this year - but only because it got so dry and that's what saved us. See his interview at the link below.
https://www.castanet.net/news/Penticton ... ly-falling

However, we still incurred substantial costs to prepare for a potential flood that could have been avoided by following the Lake Operating Rules instead of relying on the FWMT model and keeping the lake 21 cm higher than target in February.

Here is an excerpt from my previous post of May 27th:
How did we end up with these unnecessary costs this year?

I think we can all accept that the costs related to flood mitigation along the creeks and rivers were necessary. However, what you may not appreciate is that the costs incurred for flood mitigation along the lake front were not necessary. Some of those costs are detailed below:
• Manpower and material for sand bag walls, bladder dams, gabion barriers, weighted barrels on docks, log booms, etc.
• Lost tourism from negative publicity predicting likely flood
• Costs of manning the Emergency Operations Center re lake flooding
• Cost of preparations by private property lake front owners
• Emotional stress suffered by people told they must relive the 2017 flood
and...
Erosion.JPG
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Steve-O
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Re: Monitoring lake level to prevent flood

Post by Steve-O »

Nothing to see here. Move along folks.
andrea-lake
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Re: Monitoring lake level to prevent flood

Post by andrea-lake »

Steve-O wrote:Nothing to see here. Move along folks.


Indeed….nothing to see here…

From the Summit 2000 Report and from Kim Hyatt's reports, here is what experienced lake managers told the FWMT Team before they embarked on creating "fish friendly" forecasting models:

FWMT pic.JPG
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