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

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.
 
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.

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

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

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Aerial view of the concrete fish ladder.

http://www.pac.dfo-mpo.gc.ca/pacifi...lide-eboulement/bulletins/2020-05-08-eng.html
 
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.
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Work continues on the platform as part of the pneumatic fish pump system installation.

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Progress on the concrete fish ladder construction.

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

http://www.pac.dfo-mpo.gc.ca/pacific-smon-pacifique/big-bar-landslide-eboulement/index-eng.html
 
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.
 
I think its funny they are now putting in the system that was suggested on day 1 when this happened way back.

High tech fish transport system set up to ‘whoosh’ salmon past Big Bar landslide

https://www.coastmountainnews.com/n...t-up-to-whoosh-salmon-past-big-bar-landslide/
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.

 
I think its funny they are now putting in the system that was suggested on day 1 when this happened way back.

High tech fish transport system set up to ‘whoosh’ salmon past Big Bar landslide

https://www.coastmountainnews.com/n...t-up-to-whoosh-salmon-past-big-bar-landslide/
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 *** by ya statements that don't tell us much. Are there no salmon migrating through at this time?
 
WHY not post for us the ongoing results of the sonar activity and visual sightings of migrating salmon rather than these *** by ya statements that don't tell us much. Are there no salmon migrating through at this time?

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

So they probably have no data
 
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!
 
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This project was always going to cost north of 100m when all said and done.

Anyone that thought differently did not look at the price tag for hells gate.
 
Big Bar landslide response information bulletin
May 29 2020

Ongoing onsite operations
This week, a spike in water levels and heavy rain slowed progress at the site. Work on the foundation for the pneumatic fish pump system, the Whooshh Passage Portal™, was suspended for several days. In addition, our salmon monitoring team continues to encounter high water levels south of the slide site, which is preventing the installation of key monitoring equipment.

Despite these challenges, work continues on the Whooshh™ installation. Progress is being made on the electrical components, mounting the intake piping and hangars for the tubes, and placement of the last two in-river pumps. The prime contractor, Peter Kiewit Sons ULC, also continued scaling work and the installation of rock fall protection mesh.

The Province of B.C.’s River Forecast Centre is predicting water flows to reach up to 6,000 cubic metres per second (cms) for this portion of the Fraser River. Crews are taking every safety precaution as they continue to work onsite during these flood conditions. This situation may slow progress as water levels rise further. Teams are currently working diligently to redesign the Whooshh™ installation to ensure it performs in these conditions.

Monitoring fish movement at the slide site
Fish monitoring provides the key to understanding fish population size, movement and health in near real time. We will use this data to calculate the migration time of individual fish of select species, size and gender. Between now and the end of the migration season in November, two types of monitoring methods will be used above and below the Big Bar landslide site – hydroacoustic and radio tagging.

Hydroacoustic monitoring uses sonar technology to count the number of salmon successfully passing through the slide site and to track their continued migration. This method is non-invasive and does not require fish handling. The equipment counts the number of salmon and technicians can delineate between species in most cases but it does not provide data on which stocks are passing by. Each salmon stock returns to a different spawning ground. Hydroacoustic monitoring stations are currently operating below the slide site near the Big Bar ferry and 40 km upstream at Churn Creek.

Radio tagging involves inserting a tag into a fish’s stomach or attaching it to their back. The internal tag does not affect migration as salmon typically do not eat while moving upstream. The radio tag emits a signal that is detected by a shore-based receiver. The monitoring team has installed the radio receiver network to monitor fish passage through the main stem of the Fraser River and into major spawning streams. Location data from these tags provide the passage rate of fish and the survival-to-spawn rate of the stocks. The team will also collect a tissue sample for genetic stock identification and a small blood sample to assess the energy and stress levels of the fish expected to pass the slide site.

Both monitoring methods were used in 2019 during the emergency response phase to track fish passage at the slide site. The team has refined and improved its approach based on information gathered through last year's response by:

  • expanding the upriver radio receiver network to improve data collected on the survival-to-spawn rate;
  • identifying better sites for tag application to minimize the tagging effectsFootnote1 on fish; and,
  • linking fish behaviour observations to velocity maps with detailed tracking through the slide area.
The monitoring team has been onsite since May 19, however, the high freshet flows from the region’s rapidly melting snow pack are impacting the deployment of equipment. Radio tagging and sonar counting operations are underway. We expect to receive fish passage data in the coming weeks and will share this information in upcoming issues.



Working platform used to install the Whooshh Passage Portal™ tubes. Click to enlarge.



Generators for the Whooshh Passage Portal™. Click to enlarge.



Aerial view of the working platform and rock mesh installation. Click to enlarge.



Fitting a water pump pipe to the fish ladder for the Whooshh Passage Portal™. Click to enlarge.
 
 
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