Updated Hydrometric Data Charts for Lake Okanagan

[gswaters]

I have recently started producing charts for daily-averaged Geodetic Height and Water Temperature for Lake Okanagan based on Environment Canada data collected at the Kelowna Station (there are other stations located at Vernon and Penticton as well).

The Geodetic Height is measured every 15 minutes and the Water Temperature is measured every 6o minutes over the 24-hour day by an Environment Canada sensor. I take the entire daily raw data set and then average it over the 24-hour period to get a daily average.

The charts start on April 1, 2020 (Why then? COVID-19 boredom!) and continue to the most recent complete day, currently May 20, 2020.

I tweet out the daily update from @WestKelownian, usually in the morning.

Here is today's chart for the Geodetic Height (in meters) for Lake Okanagan. On May 20, 2020, the daily-averaged Geodetic Height was 342.24 m. Lake Okanagan is considered "full" when the Geodetic Height is 342.48 m. Thus, as of May 20, 2020, the water level of Lake Okanagan is about 24 cm shy of being considered "full."

The actual depth of the water column at the Kelowna Station is determined by subtracting 340.26 from the Geodetic Height. Thus, the daily-averaged depth of the Lake at the Kelowna Station on May 20, 2020 was 1.98 meters.

Here is the corresponding chart for the daily-averaged Water Temperature (in degrees C) recorded at the Kelowna Station. The daily-averaged temperature for May 20, 2020 was 12.98 C. The Lake seems to be nicely warming. I look forward to jumping in ... once it gets to nearer to 20 C!

[LANDM]

Great post. Thanks for the info!!

[stuphoto]

Just wondering, and please consider me as a complete rookie on the subject.

When the lake is considered as Full, is that based on historic levels, the point right before it overflows the banks or something else?
Does anyone have the data from the floods a few years ago as a comparison?

[Frisk]

Any guesses on how high the lake will peak this year? I'm going to say 343.00m.
They've been dumping a ton of water out of the penticton channel the past few days, presumably in anticipation of the hot weather next week. The snowpack on the east side of the valley is still very high in the upper elevations.

[vegas1500]

No guesses but I will bet no matter where it peaks, people will *bleep* about it and that the region did a *bleep* job “controlling it”.

[GordonH]

I believe it's being discussed here:
https://forums.castanet.net/viewtopic.php?f=23&t=85312

[occasional thoughts]

Low vision here, I can't make out some of the names and numbers on the various graphs, above. So my question, what is the usual or standard or normal elevation of the lake? I get it that it fluctuates based on the season, inflow, outflow, evaporation, etc. but is there a "default". Maybe the concept of "full pool".

[GordonH]

Low vision here, I can't make out some of the names and numbers on the various graphs, above. So my question, what is the usual or standard or normal elevation of the lake? I get it that it fluctuates based on the season, inflow, outflow, evaporation, etc. but is there a "default". Maybe the concept of "full pool".

Full pool is 342.48

As of this morning it was at 342.318

[occasional thoughts]

Thank you, GH. So, Frisk, you're not going out on a very large limb in predicting 343.00 (metres above sea level I presume). Well, maybe if I convert it into English (lol!), 0.52m above full pool is 20.8". That's actually a fair amount if I'm understanding the numbers correctly.

I was atop Okanagan Mountain at Divide Lake on Wed. No snow anywhere around there, some seen on distant higher peaks.

[Lady tehMa]

Thank you, GH. So, Frisk, you're not going out on a very large limb in predicting 343.00 (metres above sea level I presume). Well, maybe if I convert it into English (lol!), 0.52m above full pool is 20.8". That's actually a fair amount if I'm understanding the numbers correctly.

I was atop Okanagan Mountain at Divide Lake on Wed. No snow anywhere around there, some seen on distant higher peaks.

I was up near Big White on Saturday and there was snow on the higher elevations.

[bigtimeoperations]

Anywhere below 1500 meters elevation has only trace amounts of snow left. The other day I was up at Postill Lake (elevation 1400m) no snow whatsoever. The ridge on the east side of the lake had visible patches left, and that ridge is probably 1600 meters at most. That is likely the highest elevation in the Mill Creek watershed. As noted already, tons of snow left up by the Greystokes, which feeds Mission Creek, and is one of the highest areas to drain into Okanagan Lake. All of Big White drains into the Kettle basin, not the Okanagan.

[Frisk]

It's at full pool now, seems like it might go over a bit. I don't think it'll get anywhere near 2017 type levels though.

[seewood]

High water in 2017 was 343.250 meters asl

https://www.cordemergency.ca/updates/ok ... 07-27-1119

[gswaters]

I am posting updated (12:00am PST May 30, 2020) graphs of daily-averaged Geodetic Height and Water Temp for Lake Okanagan at Kelowna from Environment Canada Hydrometric Data.

As of May 29, 2020, the Geodetic Height of the Lake is 342.49 m (the depth at Kelowna is 2.23 m). Lake Okanagan is considered “full” at 342.48 m.

As of May 29, 2020, the temperature of the Lake is 13.44 C.

For those interested I post daily updates on Twitter at @WESTKELOWNIAN

[Frisk]

My guess of 343.00 was probably off unless we get some crazy rainfall or something. 342.80 seems more likely.