Okanagan Weather

[swamp1967]

Yes, all of Kelowna is a flood plain, but since the late 1940 and into the 1950's things changed after the dykes went up and development occured. Yes there are many variables, but as I pointed out earlier, sediment build up in the creek is an increasing problem. In 1990, 1997 and 2006 major flood events occured on Mission Creek and each time the Provincial Government removed large quantities of gravel so that the creek could handle future run offs. In 2012 this didn't happen. Between the KLO and Casorso bridge where the sediment in Mission Creek settles out, some portions didn't have any gravel removed in 2006 either. As one who lives along Mission Creek, I'll point out that unless gravel is removed, even normal snow packs have the capability now to result in flooding. So anything above normal, should be a bit of a concern.

[gman313]

Yes, all of Kelowna is a flood plain, but since the late 1940 and into the 1950's things changed after the dykes went up and development occured. Yes there are many variables, but as I pointed out earlier, sediment build up in the creek is an increasing problem. In 1990, 1997 and 2006 major flood events occured on Mission Creek and each time the Provincial Government removed large quantities of gravel so that the creek could handle future run offs. In 2012 this didn't happen. Between the KLO and Casorso bridge where the sediment in Mission Creek settles out, some portions didn't have any gravel removed in 2006 either. As one who lives along Mission Creek, I'll point out that unless gravel is removed, even normal snow packs have the capability now to result in flooding. So anything above normal, should be a bit of a concern.

I would suggest run off should be a concern for someone living next to a creek or river, above average snow pack, average, or below average. Perhaps these river / creek banks are best left to nature. Erosion is normal and we can only delay, not prevent.

[Glacier]

Note we did have record and near record rain in much of the interior. Mill Creek, Mission Creek, Shushwap River, KEttle River, all ran high and had minor floods in some area. I seem to remember the Fraser being quite high too due to rainfall.

Snowpack, weather and precipation all play a factor. We got a ton of spring rain.

Right as rain, you are.

There are really 4 things that cause extreme flood events in BC (5 if you count tsunamis). On the coast flood events typically occur in the fall/winter when hit with a particularly wet "pineapple express." While flooding from excessive rain (typically from May through September) can and does occur in the BC Interior as we witnessed last year, this not the usual source of flooding.

The worst flooding years on record in our part of the world coincide with extremely heavy snowpacks (the worst of the worst being 1894, 1948, and 1972). A lot of very heavy snow packs did not result in flooding because the melt was slow the following spring. Likewise, some years with relatively low snowpacks have been followed up by flooding due to either heavy spring rain or a very quick transition between winter and summer - or both.

The moral of the story is that a heavy snow pack INCREASES the odds of spring flooding.

There are two other ways that flooding occurs in BC. One is by means of an ice jam just as we saw in the Nechako around Prince George a few years ago.

The other means of flooding, though impossible in the Okanagan, is with a jökulhlaup. Jökulhlaups have been known to wipe out entire towns and communities as an entire lake drains in a very short time. Typically, the glacier at the end of a lake begins the float when the lake level reaches a high enough level. This causes the water to rush under the glacier or ice dam, and since it gouges its own channel, there is no stopping it until most of the lake drains. Generally, no one knows a Jökulhlaup is about to strike until it's too late.

[swamp1967]

I would suggest run off should be a concern for someone living next to a creek or river, above average snow pack, average, or below average. Perhaps these river / creek banks are best left to nature. Erosion is normal and we can only delay, not prevent.

What most don't understand about Mission Creek, is that most of the creek banks are made of unstable gravel that was pushed up from the bed with equipment to build dykes. You cannot leave these dykes to erode or you'll flood Kelowna. I agree we can only delay and not prevent, but there isn't much choice now with that since a city was built around Mission Creek.

So I personally think that the snow pack will increasingly less important to Mission Creek as the condition of the creek with regards to the large amounts of sediment becomes worse.

[Woodenhead]

What most don't understand about Mission Creek, is that most of the creek banks are made of unstable gravel that was pushed up from the bed with equipment to build dykes. You cannot leave these dykes to erode or you'll flood Kelowna.

I was going to post this myself. Mission Creek is dyked for certain sections, so you can't just leave it; it needs maintenance.

[Homeownertoo]

I'm expecting a story on the upcoming drought in the Okanangan any day now.

[Donald G]

To Swamp67 and Glacier ...

Thanks for providing the interesting information c/w illustrations.

The Salton Sea in California, the largest LANDLOCKED salt sea in North America, that the last part of the Colorado River eventually flows into (and evaporates) was formed in just such a way. The outflow system debris continually built up just as is happening with Mission Creek and the level of the Pacific Ocean dropped 200 feet leaving the Saultan Sea 200 feet below sea level. The rising brine content, which over the years wiped out all except one species of fish, is now midway between the Pacific Ocean and the Dead Sea in the Mideast. The large farms and orchards in that area of California are finding it harder and harder to find long term water sources for their crops. What is not watered has reverted to desert.

[Sonny Taylor]

The Salton Sea in California, the largest LANDLOCKED salt sea in North America, that the last part of the Columbia River eventually flows into (and evaporates) was formed in just such a way. ... ...

I guess you meant the the Colorado River (not Columbia). Quite a colourful history for the Salton Sea actually.

[Lady tehMa]

So hail this weekend, and snow yesterday and today. At least it isn't sticking . . .

[Queen K]

You got snow where you are right now?

[Lady tehMa]

Coming down, but not sticking. Not as heavy as the burst we had yesterday.

[Catz]

snow in Glenrosa

[Bsuds]

Snowing here too!

[oneh2obabe]

snow in Glenrosa

Keep it there.

[Catz]

LOL...babe...can hardly make out the mountain out my window...this is yucky!