Another jetty, another breach project
Raincoast has begun a new connectivity restoration project on the North Arm jetty.
As we make our way the 3 km walk to our work site on the North Arm jetty and start to hear the sounds of heavy equipment moving I can’t help but smile. After a challenging few months navigating permitting processes, lease agreements, engineering designs and finding a contractor it is a huge relief to see the project underway. And within a few short weeks, construction will be done and it will be almost time to start monitoring the results.
The project we are undertaking is to create a breach in the North Arm jetty in the Fraser River Estuary, a structure that has disconnected habitats in the north part of the estuary for over 100 years. Our breach is 30 meters wide and will be connected on mid to high tide levels, providing juvenile salmon access to the vast brackish water habitats in the centre of the estuary, which they rely on to transition to the increasing salinity of the water before making the final push to the open ocean. If all goes well, we will be back next year to create a second breach in the jetty to further restore connectivity and the natural processes which help to build a healthy and resilient delta.
Building upon previous success
This project builds upon our recent success in restoring connectivity through the Steveston jetty, another major barrier in the Fraser Estuary. The Fraser River splits into two arms as it flows through Metro Vancouver, the South Arm which carries the majority of the flow and meets the ocean at Steveston, and the North Arm, which takes less of the flow but still provides important habitats for salmon, and enters the ocean just south of the City of Vancouver near YVR. Both arms of the river had similar jetties built in the early 1900s to hold the mouth of the river in a fixed location and allow for dredging of the channels for navigation.
Prior to this, the mouths of each arm would meander over the years, depositing sediment and creating a shallow channel which made entering the river for navigation challenging. Once the jetties were in place, the channel was dredged, and shipping activity began to occur. Over 100 years later, we are finally able to incorporate considerations for juvenile salmon and the many other organisms that rely on the estuary.
Planning for this project began in 2017 when we first evaluated options for restoring connectivity across the Fraser Estuary. We looked at the various barriers which existed in the estuary including the Steveston North jetty, the North Arm jetty, the McDonald Slough Causeway and the Iona Sewage Outfall jetty. We then did hydraulic modeling studies for all projects to look at potential outcomes and designs as well as creating cost estimates to determine what was feasible with our grant funding. We took on the Steveston North jetty for our first project in 2018, based on our estimates of overall potential benefit and the level of funding we had available.
We did baseline monitoring across the entire estuary and continued to pursue all of the proposed projects as we know they will all benefit to juvenile salmon in the estuary. Now that we have finished our work on the Steveston North jetty, we are very happy that we have found the funding to turn our attention to a second structure and continue to transform the estuary into an place that can support our juvenile salmon and broader ecosystem processes.
You can help
Raincoast’s in-house scientists, collaborating graduate students, postdoctoral fellows, and professors make us unique among conservation groups. We work with First Nations, academic institutions, government, and other NGOs to build support and inform decisions that protect aquatic and terrestrial ecosystems, and the wildlife that depend on them. We conduct ethically applied, process-oriented, and hypothesis-driven research that has immediate and relevant utility for conservation deliberations and the collective body of scientific knowledge.
We investigate to understand coastal species and processes. We inform by bringing science to decision-makers and communities. We inspire action to protect wildlife and wildlife habitats.
