By reading your post on another thread, it looks like you beat me to the punch this year Chris. I've been complaining about gravel extraction in the Fraser drainage for a long time. My posts last year were fairly aggressive. If you can remember, I was complaining about lack of best management practices during extraction practices, (no silt fence, refuelling in critical areas, no biodegradable hydraulic fluids in machinery below OHWM, lack of safety practices which lead to a fatality last year, etc, etc.).
I had a meeting with the Mayor of the City of Chilliwack and here director of Engineering and brought up these concerns on the Vedder and Fraser Rivers.
I also have arranged a meeting early in the new year for our technical people from the Fraser River Gravel Stewardship Committee to present our case to all of Chilliwack Council members.
We have a meeting of the committee this Friday also as we continue to work on this, into our 5th year now and it is a struggle to get things changed as this is driven by the province and FOC seems to continues to let it happen.
Here is some recent info for you to dissect. We received this from FOC why they allow gravel extraction on the Vedder. It started from some queries I made to FOC and one of our FRCSC members asked these additional questions.
how is gravel removal in the Vedder affecting chum spawning habitat and chum spawning numbers?
As stated in my email below I understand that the majority of chum in the system spawn upstream of the Vedder Crossing bridge, and that chum prefer to spawn at the downstream end of bars, where there is typically upwelling flow of water through the gravels. On larger bars these upwelling areas are sometimes identified by seeps at the downstream end of bars. The upwelling due to hydraulic pressure, even on undisturbed bars, can cause a quick-sand type of condition. I have not yet walked along the gravel removal areas this year to make my own assessment. The gravel removal impacts to chum spawning are relatively temporal and features such as enhancement of chum spawning areas are included in the gravel removal plan. Significant fish habitat enhancement projects have also been completed within the Chilliwack river flood plain in the past.
- Can you please provide me with an outline of what is the design flow and how many years of gravel removal has to take place to allow many to believe that it must continue to be removed every second non pink year?
- Does DFO still abide by the intent of the gravel removal policy that DFO Pacific Region forwarded to the Province in 2000?
- How does DFO assess the need for such mining programs in fish habitat or are technical staff expected to not question any such program proposed by the province or local government and if so, why?
The province and/or local governments are responsible assessing and managing flood risks in the area. The design flow identified by the province is the flood flow with an expected return period of once every 200 years. That flow rate is based on Water Survey of Canada flow gauge information, and is 1470 cubic metres per second. Cross sections of the river are collected every 2 years, and computer flow models are used to identify areas of the setback dykes that may be overtopped or close to overtopping during a design flow event, then removal areas are identified and designed to manage the gravel budget and flood profile along the Vedder River. Gravel removal targets are equal to gravel inputs from upstream. Raising of Dykes has occurred where needed as well. Through DFO's participation on the technical committee we have the opportunity to discuss the flow modeling results and flood mitigation options.