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October 27, 2017 7:38 pm

No Change in Nechako Situation

Thursday, December 22, 2016 @ 11:23 AM

Prince George Fire Rescue uses Nechako River water to create a high pressure “blast” on ice. Photo courtesy City of Prince George

Prince George, B.C. –  It’s been a little over a week since ice   on the Nechako River started  jamming up at the confluence with the Fraser   and   while the City  maintains  its level one emergency operations centre,  there has been no major  change in the level of the Nechako River.

The City  started  clearing ice  from  a back channel  that runs under the Cameron Street replica bridge,  and  that  seems to have  assisted  in  keeping the level of the River  from  rising says City Communications Director Rob Van Adrichem.

Today,  Prince George Fire Rescue was using high pressure water flow  of water being pumped from the Nechako,  to  break up some of the ice ( see photo above).  Van Adrichem says the  water blasting “seems to be working.”

With the  holiday weekend nearly here, the  City has taken some steps to  make sure  any changes  in the  Nechako levels  are noted.  “We will  continue monitoring  the situation  throughout the holiday” says Van Adrichem, as  Prince George Fire Rescue will  be checking  various locations throughout the  weekend and early into next week.

(At right,  the  back channel that runs from the Nechako under the  Cameron Street  replica bridge -photo 250News)nechakodec222

There has been  no  change in the length of the stationary ice,  holding at 12 kms upstream from the confluence  although  a few more channels of open water have formed  leading to the Fraser River.

As a precaution,   the City  will be  delivering notices to  residents along P.G. Pulpmill Road and to businesses along River Road to  let them  know there will be sand  and  bags  available should  those property owners  feel there is a need to  further protect their properties.   At this point,  there have been no reports of any  flooding either by water from the Nechako  or groundwater,  the offer of sand  and bags is  just a precaution in the event  the  levels should rise.   Those  wanting sand and bags can call  either 250-561-7534 or 250-614-7828  to arrange to have sand  and bags delivered.   Then it’s up to the property owner to fill  and place the bags.

With temperatures expected to  dip  back into the deep freeze,  there remains a possibility of  more ice forming.


Depth Charges, blast that channel out! LOL

    Det cord with a booster every ten feet or so should do it..

    No leave it alone. Just about every city in the world has some sort of flooding problem at some point. Let those who built below the water line pay the price. If you want to play in the river get a boat, don’t build there and expect others to pay to rescue you.

Good advise Northman and He spoke. If the city would have listened to some of the knowledgeable guys a few years back we wouldn’t be in this predicament. DREDGE-DREDGE-DREDGE. SO SIMPLE.

    Prove it!!!!

Proof is in the pudding. It is very obvious that the scientific community has no solution. We’ve spent millions ,added hot water ,hired an ice buster, sprayed water on ice, moved ice and guess what, we still have a problem. Lets put some shovels in the ground this spring and see what happens. Its worth a try. Studies and theories have not worked so far. Its time to fix the problem, not put a bandaid on it.

    that makes sense, our city doesn’t seem to have any, or don’t seem to use it if they do.

      It only makes sense to those who do not understand why it typically does not.

      The ice is what has to be prevented from forming. Making a channel deeper does not prevent ice from forming and especially doe not prevent it from creating an ice jam when it hits the Fraser River ice as it did this year.

      There are ways that ice formation can be reduces or, if formed, can be broken up before it hits the river confluence.

      Do some research and learn. The Fraser in PG is not a shipping channel.

      Gus, give your head a shake. The ice jam isn’t created because the ice on the Nechako is hitting the ice on the Fraser. The ice on the Nechako is jamming because it is running aground on the shallow river bottom of the Nechako. This isn’t rocket science.

“There are ways that ice formation can be reduced, or if formed, can be broken up before it hits the river confluence” You used hot water ,didn’t work. You used the ice buster, didn’t work. You sprayed water on it, didn’t work. You built dikes, didn’t work. Your solution of spending millions and DIDN’T WORK IDEAS is all but used up. Look outside your tiny box.

    None of the methods you described dealt with ice formation. Every single one dealt with ice floes AFTER they were formed and down river of where they formed.

A deeper wide Nechako river channel will stop this problem.

    The Prince George Citizen digitized edition dated January 5, 1950 (which was before any effect would have been felt from the Kemano development) provides some interesting information from an exchange between the Northern Interior Lumbermen’s Association which had about 12 remanufacturing and lumber processing plants north of the First Avenue CN yard. That correspondence had started in February 1948 with a letter to John McInnis, MPP for Prince George.

    It cited the serious floods caused by ice jams in the years 1917, 1921, 1926, 1933, 1937, 1941, 1944 and 1946. It also stated that those floods had chiefly affected the CN properties.

    The Association stated that “the general opinion of those who have studied the cause of these menacing ice jams is that they are caused by the gradual silting up of the Nechako River channel at the point where it joins the Fraser River, and that the dredging out of a clear channel for the Nechako River waters at that point would be a corrective measure.”

    Mr. Mcinnes passed the letter on to the Deputy Minister of Public Works who then wrote a memorandum to the Minister of Public Works in which he stated: “the NILA are correct in stating that the difficulty with ice at Prince George is quite serious. To date the CNR have been the most seriously affected but the situation has changed materially in recent years in that the industries have been established all along the CNR between our bridge (Cameron Street Bridge) and the CN bridge over the Fraser and, for the most part, on the river side of the track. The ice very probably does considerable damage to their properties and, in addition, ties up operations for a considerable period.” He goes on: “As to the proposal to dredge out the Nechako River channel at the confluence of the Nechako and Fraser, I am afraid we are in no position to state whether or not this would have any effect on the ice flow. One would have to o into very careful survey and study of the conditions pertaining when the ice starts to run.”

    Finally he describes where the toe of the ice jam is” “……the initial jam takes place above the CN bridge ….. I have seen seven feet of ice over the CNR tracks, with a considerable part of the river flowing down the trench excavated in the ice by the CNR. …… insofar as public works are concerned, a large expenditure would not be justified.”

    Based on the opinion of the Deputy Minister, the Minister then passed the memorandum on to Mr. McInnis, MLA and included the following words: “It would appear that our works are not particularly affected by flooding conditions caused by ice jams in the river and remedial measures, if feasible, should be undertaken by those concerned …..I feel we should not, at the present time, undertake this additional responsibility unless there is a definite commitment on the part of those affected that they will underwrite the financial obligation necessary for such remedial work.”

    source= pgnewspapers.pgpl.ca/fedora/repository/pgc:1950-01-05-11

    To this day, almost 70 years later, whether it is the province or the City, the position remains the same. The land owners chose to locate at the river’s edge. They even observed or could have done their due diligence and found ice jams on average 5 years apart. The land owners pay, just as they did with the recent riverbank riprap placement on the banks of the Nechako. The City took the same position taken by the province in 1948.

    The railway, on the other hand, had no historic information to go by when they built the original bridge and track. The understanding in 1914 of such river action was also far less sophisticated as it is today. Notice that the CN cut a trench in the ice at their cost to try to mitigate the effect of the ice jam.

    Many large cities live with the consequences of such lack of knowledge through no real fault of theirs. However, when economic benefits dictate, major remedial works are often undertaken by government in modern times.

    So, locally, and in several other areas in Canada, the impasse, after 70 years and more, is still one of non-experts saying “DREDGE” while engineers and government say: “THERE IS NO PROOF IT WILL WORK”.

    I also note that the toe of the jam is still in the same location, just to the north of the CN Bridge. Other Nature remains true to her “path of least resistance notion”.

    Based on river hydraulics and the logic of “ownership of the problem”, I side with the Government, be it Province or City, in the case of the Nechako/Fraser confluence.

      “Other Nature” = Mother Nature. … :-)

      BTW, it seems the ice jams have been occurring at about the same frequency since the location was inhabited by an ever increasing number of non-aboriginal settlers, no matter what happened to the amount of water flowing down the Nechako as a result of damming the river.

      Does anyone know if there are verbal history stories from the Lheidli T’enneh about river ice and ice dams? Possibly there are some records from the Hudson Bay factor at the trading post. There was probably not reason to explore the Nechako until the ice left the rivers.

OK I concede.. Lets just do more studies, go down and watch the river flood. Bring a blanket and hot cocoa. See Ya There!

    gopg2015 wants proof that dredging will work yet offers no proof that it will not work. One thing that is for certain, if nothing is done, nothing will change.

      Didn’t they at one time dredge the river for gravel? Was it just a rumor or true?

      Klein operated out of the property on the Fraser at the confluence, the location where you can still take a car and drive a few hundred metres towards the center of the Fraser at low water, typically in August.

      That is actually the toe of the ice jam that was talked about in the 1948 letters and what is in the latest pictures from this year the location of where the “ice dam” is, just north of the CN bridge.

      There are several channels, but the main one is on the north side of the Nechako, where the pulp mills built their water intake, which then crosses the Fraser at that point to the east side of the Fraser.

      If one were to invest as much as some in Europe have done to “canalize” the river by building solid walls at banks for 5 to 10 km, and make sure that the the ends of the walls will divert the flow of the river away from scouring behind the walls and causing them to eventually fail, then one will solve the problem for a few hundred years with maybe one event every 50 or so years.

      I do not have any clue with how much that would cost, but definitely much greater than $250 million.

      Let’s go for it, see if it will work.

There is a bow in the river at Cologne, Germany. The Romans chose that site to build a northern fortified provincial town which began as a small military outpost in 50BC. There was an island at that time on the west bank which was settled by the conquered Germanic “natives”. The main channel of the Rhine would have been on that inside of the bow.

The east side of the river was relatively well protected because it is the location where the natural gravel deposits occurred, exactly the same as all along the Nechako.The outside of the bow is heavily fortified with a vertical wall to prevent scouring, in addition, an artificial island was built

Picture of gravel bar on the inside bow of the Rhine river at Cologne Germany during a low water event.
wall alamy.com/stock-photo-a-man-walks-along-the-rhine-river-banks-with-very-low-water-level-99548843.html

On the other side, the outside of the bow, one can see the masonry/concrete vertical dike which protects the city. The visible part of the wall is about 3 storeys high.

This is a picture of the Rhine flooding in 1983, which often breaches the 3 storey high dike, but was especially high that year.

There is an international agreement in place to reduce the effects of such “canalization” over about 200 years along the Rhine which has led to such extreme flood events. The main principle is to give the river enough room (width) to allow the water to spread out where there is no intense urban development, including constructing weirs from transportation channel dredging gravels. The intent is not to deepen the channel but to widen the river along its 1,320 km course (about the same length as the Fraser River).

source = rivernet.org/rhin/rhineriver.htm

The US army corps of engineers is taking the same course of action to mitigate flooding along the Mississipi, which is also a main navigable river in the USA with many areas being dredged for transportation purposes.

It should be noted that despite the dredging of both rivers, the floods still occur. Luckily, they only have spring freshettes to handle without the addtional problems of ice dams.

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