Rock slide in Fraser River, B.C., may hinder salmon passage

Discussion in 'Conservation, Fishery Politics and Management.' started by wildmanyeah, Jun 26, 2019.

  1. shuswap

    shuswap Active Member

    Sonar monitoring hasn’t started yet. Covid has had an impact. But should be underway in May.

    Covid is the new reality at the moment and it has created some significant logistical issues for field work. It’s not just business as usual. Lots of considerations. Need to keep everyone safe.
  2. GLG

    GLG Well-Known Member

    Big Bar landslide response information bulletin
    May 1, 2020

    Ongoing onsite operations

    Earlier this week, work onsite was impacted by the high freshet flows from the region’s rapidly melting snow packs. During this time, crews readjusted to make progress in other areas such as the installation of anchors that will suspend the tubes for the pneumatic fish pump.

    Water levels have since dropped and construction has resumed on the concrete fish ladder, which will guide fish to the pneumatic fish pump system. Efforts are now focused on fully completing the base of the fish ladder while the river remains in check.

    Big Bar ferry operations have been suspended since last week as a result of the high water. Work onsite continues to be supported by river boats and crews, who provide site transport and are responsible for swift water rescue.

    Prime contractor Peter Kiewit Sons ULC continues to face weather challenges with high winds slowing renewed rock scaling and the spring thaw impacting road conditions.

    What do high water levels mean for fish?

    Fish should be able to migrate upriver naturally during moderate flows from approximately 1,700 to 3,200 cubic metres per second (cms). Work completed this winter is expected to significantly increase the time during which these levels exist. Higher volumes will be tempered, improving the ability of fish to pass through the slide area on their own.

    The cooler spring temperatures delayed the onset of freshet but the Fraser River flow now exceeds 3,200 cms. These elevated volumes mean the “nature-like” fishway will not be viable until the return of more moderate conditions.

    The pneumatic fish pump system is expected to be in use by the end of May, when fish usually arrive at the Big Bar landslide site. This system will transport migrating fish when water levels are too high for them to use the “nature-like” fishway.

    Finally, fish migration and hydrological monitoring programs throughout the spring and summer will help provide accurate information about fish migration to support further planning.


    Installation of anchors that will suspend the tubes for the pneumatic fish transport system.

    Construction of the concrete fish ladder was hampered this week by rising water levels, as seen at the bottom of this photo.
  3. Dave

    Dave Well-Known Member

    Any idea where they are measuring discharge? used to be at Hope but that may have changed.
  4. wildmanyeah

    wildmanyeah Crew Member

    They have one near big bar
  5. Whitebuck

    Whitebuck Well-Known Member

  6. SerengetiGuide

    SerengetiGuide Well-Known Member

    This weekend looks to be hot up there...sure water levels will spike, but as someone said maybe it is better to melt a bunch of that snow before the fish show up in June. Only worry is another excuse for DFO to shut everything down.
  7. GLG

    GLG Well-Known Member

    Big Bar landslide response information bulletin
    May 8 2020

    Ongoing onsite operations
    Work continues to progress on the pneumatic fish pump system, despite pauses in construction this week due to high water levels.

    An unexpected rock fall earlier in the week highlighted the hazardous and dynamic operations at the Big Bar landslide site. Previous slope reviews did not detect this instability. Fortunately, there were no injuries.

    Crew safety is paramount. Prime contractor, Peter Kiewit Sons ULC, has implemented a number of measures to further enhance safety at the worksite following the rock fall. First, Kiewit installed a concrete retaining wall along the affected rock fall area. A dedicated spotter is now onsite during work hours to watch for falling rock and alert workers with an air horn and by radio should they detect movement. The number of workers in the construction area is also being limited and once the construction of the fish ladder is completed a mesh curtain will be installed on the slope to protect the site during summer operations.

    Presentation to Maa-nulth Fisheries Committee
    On May 4, we shared an update with the Maa-nulth Fisheries Committee regarding winter work milestones, spring work underway and planned summer work. Participants were pleased with the progress and acknowledged the work of everyone involved to restore fish passage at the slide site.

    What is a concrete fish ladder and how does it work?
    To support fish passage at the Big Bar landslide site this summer, crews are constructing a temporary fish ladder that will guide fish to a holding pool. From there, fish will enter the pneumatic fish pump to migrate past the slide site.

    Fish ladders are either permanent or temporary structures built to provide alternative fish passage through a barrier. While designs vary based on the type of obstruction, flow levels, and species of fish affected, the general principle is the same. These structures contain a series of pools that fish reach by swimming against a directed flow, then leaping through rushing water to a pool to rest. Fish repeat this process until they re-enter the river upstream. Fish ladders are designed to ensure that the water velocity does not exceed the swimming speed of fish to aid movement.

    The temporary model being built at Big Bar is a commonly used ‘vertical slot fishway’ design; similar to the permanent one installed at Hell’s Gate. Fish will swim through a thin, vertical open slot between each segment, or ‘cell’, that makes up the ladder. Each cell is approximately 30 to 40 centimetres higher than the previous one. The ladder can operate at varying water levels and takes advantage of natural fish migrating behavior.

    Usually, a ladder allows fish to swim past a barrier aided by river water flowing in from the top. At Big Bar, work is being done to create an artificial stream of water through the fish ladder. Starting with a series of large pumps supplying water or ‘attractant flow’, fish looking for an alternative route over the slide will be lured upstream into the pools. As fish swim further, they will end up in a holding pool at the same elevation as the fish pump. The use of a fish ladder encourages ‘volitional entry’, or natural fish behavior whereby they willingly enter the pneumatic fish pump. The use of this structure will help minimize stress to fish from handling and increase fish health – both key deciding factors for the design choice. The fish will then enter the pump and move over the slide site using a series of long tubes, suspended by a hanging system, above the river level.

    In addition to acting as the entrance to the pneumatic fish pump system, the temporary fish ladder will play another critical role at the slide site. Should there be a gap in fish pump operations for any reason, teams will be able to collect fish from the holding pool, transfer them to tanks, transport them 4.5 km north to the French Bar Creek riverbank, and release them into the Fraser River.

    When completed, the concrete fish ladder will be approximately 50 metres long. Building such a large temporary structure on difficult terrain, and ensuring its design is attractive to fish, was a challenge. In response, the ladder is located on a bench as close to the barrier as possible so fish can easily find it. The temporary structure is secured with large boulders to help reduce potential erosion of the work area. During freshet, currents can exceed eight metres per second. Therefore, crews are building the structure from bottom up, using steel rods to reinforce 500 interlocking concrete blocks to maintain its structural integrity.

    There are a number of unique features to the Big Bar modular concrete block fish ladder. Studies have shown that salmon migration in the Fraser River occurs primarily during daylight hours, with peak activity in the early mornings and evenings. To extend this activity into the nighttime, crews are placing large floodlights at the entrance of the ladder to guide fish into the pool. Crews are also building a ‘debris boom’ at the entrance to prevent material like logs from entering and damaging the pumps.

    Although rising water levels and difficult terrain continue to challenge construction, the team is making progress. Once operational, the temporary fish ladder will play a critical role in supporting fish passage over the slide site during the summer should natural passage be impeded.

    The working platform will help crew with the installation of the pneumatic fish pump system tubing.

    Steady progress is being made on the construction of the fish ladder, despite high water levels this week.

    Aerial view of the concrete fish ladder.
  8. fogged in

    fogged in Well-Known Member

    Very impressive!
    Great to see such an overwhelming effort to solve this huge natural disaster.
    Hope it's successful!
    Pineapple Express likes this.
  9. GLG

    GLG Well-Known Member

    Big Bar landslide response information bulletin
    May 15 2020

    Ongoing onsite operations
    This week, site preparation continued for the arrival of the pneumatic fish pump system, also known as the Whooshh Passage Portal. The first 2-lane system will be operational in early June, which is later than expected due to significant complexities with installing the mounting hardware that will support the long tubes on the canyon wall.

    Fish typically start arriving at the slide site in mid-May. Various species will continue migrating through the area until November, with the sockeye peak migration expected to occur in mid-late August. We are working closely with local First Nations to transport early arrivals 4.5 km upstream until the 2-lane system is operational. A ‘truck and transport’ method will be used with specially designed tanks. This system will also be available in case there are any gaps in Whooshh operation throughout the season.

    This week marked another significant milestone on the Big Bar project: the completion of the concrete fish ladder. The ladder will allow fish to swim up to a holding pool where they will either enter the Whooshh Passage Portal or be collected for truck transport. Last week’s information bulletin included a full feature on the concrete fish ladder.

    Construction is now focused on:

    • building the foundation for the Whooshh Passage Portal;
    • installing a pad for the generators that will power the pump system; and
    • constructing the support structures to mount the tubes.
    Work continues on the platform as part of the pneumatic fish pump system installation.

    Progress on the concrete fish ladder construction.

    Generators on this pad will power the pneumatic fish pump system.
  10. wildmanyeah

    wildmanyeah Crew Member

    Big Bar landslide response information bulletin
    May 22 2020

    Ongoing onsite operations
    This week, preparations onsite continued for the arrival of the pneumatic fish pump system, known as the Whooshh Passage Portal™.

    With anchors now installed and tested, crews started mounting the Whooshh™ transport pipe hangers. To secure the hangers along the undulating canyon wall, prime contractor Peter Kiewit Sons ULC (Kiewit), has constructed a walkway with safety lines to allow access. The generators that will power the Whooshh™ system have also been successfully installed and tested.

    In addition, crews have finalized work on the concrete fish ladder with the installation of a guardrail around the ladder’s perimeter. Kiewit has also installed a set of submersible water pumps that will supply the fish ladder and Whooshh™ system.

    As part of ongoing safety work, Kiewit has installed additional rock fall mitigation mesh at multiple locations as well as a stabilization curtain along the west beach slope.

    Finally, on May 13, Kiewit added an additional shift to advance work on the infrastructure required for summer operations.

    Long-term planning
    In January 2020, two technical working groups were established to support the development of mitigation and remediation plans for alternate fish passage and conservation-based enhancement at Big Bar. The groups include experts from three levels of government, stakeholders, non-profit organizations and academia.

    This week, these groups met to consider strategies and options at a long-term planning session. The group will establish the criteria for a decision matrix that will guide future work during the 2021 winter construction season. The definitive goal is to ensure full, natural fish passage at the slide site.

    Additional sessions are scheduled for the coming weeks to finalize options and develop a statement of work.


    Guardrails being installed around the now-completed concrete fish ladder. Click to enlarge.


    Progress on the platform allows crews to work on the Whooshh Passage Portal™ tubing installation. Click to enlarge.


    Installed and tested, the generators will power the Whooshh Passage Portal™ when operational. Click to enlarge.
  11. Pineapple Express

    Pineapple Express Well-Known Member

    Does anybody have a link to view this spot on Google Earth satellite view?
  12. GLG

    GLG Well-Known Member

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  13. Pineapple Express

    Pineapple Express Well-Known Member

  14. Whitebuck

    Whitebuck Well-Known Member

    Any news on if the sonar is up and running yet?

    Would love to see the counts.
  15. Dave

    Dave Well-Known Member

  16. wildmanyeah

    wildmanyeah Crew Member

  17. GLG

    GLG Well-Known Member

    Yes it was suggested at first but the risk of success was not good for what was needed to install it at that time. Now we have a road to the spot and the chance of success are immensely better.

    littlechucky likes this.
  18. terrin

    terrin Well-Known Member

    While seeing a high mortality rate in May and June of 2019, Roberts expects to see salmon death almost completely avoided this year.

    “There should be no mortality,” he said, noting DFO has been working closely with First Nations and the Province to find solutions to the problem.

    “We see the fish here as vital to all things for the salmon fishery and we need to find an answer … we are looking at the destruction of salmon stock if we don’t help, or facilitate, and let fish passage happen.” WHY not post for us the ongoing results of the sonar activity and visual sightings of migrating salmon rather than these cum by ya statements that don't tell us much. Are there no salmon migrating through at this time?
  19. wildmanyeah

    wildmanyeah Crew Member

    If I recall correctly they have to pull the sonar during high water.

    So they probably have no data
  20. Whitebuck

    Whitebuck Well-Known Member

    Surely there is areas that sonar can be done. Especially since they had sonar running the last week of June when the water was higher and more turbid.
    With areas of calmer water that are directly upstream and all the way to PG.
    Saw another part in that video that says only 6000 Chinook migrate past the slide in July?:rolleyes:o_O

    Much easier to have no data and keep the ocean closed to protect these early chinook that dont get encountered until the FN openings in the Fraser!
    Last edited: May 27, 2020 at 11:07 AM
    High Time and CIVANO like this.

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