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October 27, 2017 7:44 pm

City Provides Video of River Fly Over

Friday, December 16, 2016 @ 6:13 PM

Prince George, B.C.- The City of Prince George has  provided  a video of the fly over of the  Nechako and Fraser Rivers  today.The video shows stationary ice on the Nechako River just west of the Foothills Bridge, about 10km upstream from the confluence with the Fraser. On the Fraser, stationary ice is evident down to Fort George Canyon. The total length of this ice is roughly 35 kilometres. Despite the extent of ice, patches of open water are visible, and water levels appear to be dropping.

The water flow in the Nechako River is approximately 200 cubic metres per second, which is about twice the normal volume for this time of year. Officials with the Province are indicating that the elevated water levels are primarily as a result of heavy fall rains in the Stuart – Takla watershed northwest of Prince George. They also report that discharge from the Nechako Reservoir is as low as it can be during the winter  at about 32 cubic metres per second, which is the typical  flow  from the Skinslake Spillway at this time of  year.

City crews have been monitoring a groundwater piping system under River Road that provides evidence of water levels below the surface. Currently, no groundwater has been evident in the pipe.

250News will provide the  latest information  as it  becomes available.




Too bad the video speeds up in so many places. I stopped it in several locations to see what is going on with some more detail.

The City has an interesting site giving some “facts” at: princegeorge.ca/citybusiness/longrangeplanning/floods/Pages/QuickFacts.aspx

There were 5 ice jam events from 1917 to 1955 = 39 years or an average of one event every 8 years.

There have been 22 ice jam events from 1956 to 2016 which is a 60 year period or one event every 3 years.

There is interesting terminology introduced for the Dec 1996 event. It is called a “Major Ice Jam Event”. Why the difference?

Seems that we there is no comparable criteria. I know that I have lived here since 1973 and there sure have not been an ice jam event at an average of one every three years.

Use some more scientific criteria such a flooding resulting from the ice jam, thus water levels would be the key indicator. I am sure there are a couple more indicators which could be used which would describe the severity beyond a stack of ice floes gathering on the southern shores on the sand bars.

Well you’re lucky. For me, it won’t even load!

you can bet the city paid premium prices for substandard product.

From 1917 to 1955 there was more water flow in the Nechako therefore the water was deeper. the deeper the water the less chance of freezing. After 1955 when the river was controlled by The Kenny Dam, there was less water and more silting. More silting and less water means that the river at the confluence is not as deep as it used to be. By dredging a channel, this area the water will more concentrated making it deeper and faster this will lessen the ice build up.

    That is a nice story, but there is little fact to it.

    Go to the video and stop the play at the 17 second mark. You can see the open water (typically indicates a fast moving water flow) and observe the water flow from the Nechako coming from the north side of the river, which is likely a location the primary flow has been for hundreds of years based on the nature of water flow in rivers at a bend.

    It then crosses the Fraser to its east side and flows as an open waterway down the Fraser.

    Then look at where the toe of the ice build-up is. It is as it hits the Fraser ice on the west side of the Fraser. That is where the ice jam starts to build up and then the remainder of the ice coming down the Nechako starts to pile up.

    There was no flooding to speak of at this time. The Rivers were able to handle the waterflow quite nicely. The ice that piles up into the jam begins to form further up-river on the Nechako. That is where preventative measure can be taken and that is the most common method of trying to control ice jams throughout the world. Dredging rivers is primarily used to maintain navigable waters deep enough for shipping traffic, not as a prevention of ice jams and flooding.

Will not load on any of my mobile devices but viewable on my computer

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