Colquitz River
The Colquitz River is home to both coastal cutthroat trout (Oncorhynchus clarkii clarkii) and coho salmon (Oncorhynchus kisutch). In recent years, the number of coho spawners has declined, however, even a few spawning salmon give us hope that with proper habitat restoration, these fish can recover and succeed in urban watersheds with their incredible resilience.
For decades, dedicated volunteers and community stewardship groups have worked to rebuild fish populations and improve the health of the Colquitz Watershed. Since 2019, Peninsula Streams has been partnering with the District of Saanich every summer to restore and enhance Colquitz River habitat with the help of community volunteers. To date, we have restored over 400 metres of important salmon habitat.
The Challenge
The Colquitz River watershed has extensive urban and suburban landscapes and land uses that impact the natural environment. These include lower flows during summer, higher flows in the winter due to impervious surfaces, poor water quality, increased sedimentation and bank erosion, loss of riparian vegetation, higher water temperatures, and an overall reduction of habitat.
Despite these human-caused impacts, the watershed offers remarkable opportunities for restoration and conservation efforts. This is largely a result of the foresight of District of Saanich staff for keeping the river channel out of pipes and open within a park trail system.
Our Solution
With the help of the Friends of the Colquitz Mainstem and working in partnership with the District of Saanich, we have restored over 300 metres of riparian and instream habitat in Colquitz Creek, mostly within Copley East Park.
Following the success of the first 2019 project where we restored 120 metres of the river, we again partnered with the District in 2020 to restore an additional 80 metres of habitat, creating a total of roughly 200 metres of continuous, high-quality habitat. In 2022, we added another 100 metres of high-quality salmon habitat.
Instream work involves constructing boulder cluster runs and Newbury weirs (riffles) with spawning gravel beds which help with oxygenating the water and increasing aquatic invertebrate diversity, providing important food sources for fish. Deep pools, large rocks, and woody debris are also added to create habitat for fish and to repair bank erosion. Viewing platforms are also installed to allow for park visitors to spot salmon returning to spawn in the late fall. Riparian areas are enhanced by adding healthy, clean soil and then replanted with native plants by volunteers. Newly replanted areas were protected with split-rail fencing.
We continue to work with the District and support the Friends of Colquitz Mainstem to coordinate and implement stream monitoring, riparian planting, and maintenance.
To learn more about the Colquitz, check out our webinar:
Setting up a dam on the Colquitz River
Restoration includes adding rock-crests with spawning gravel, large rocks, and woody debris to enhance fish habitat and protect against erosion.
Colquitz reach restored in 2019
Copley Park Restoration
Project done by UVic Community Mapping on Colquitz River restoration.
The process of restoring the stream has resulted in a healthier habitat for a variety of native species such as coho salmon, coastal cutthroat trout, otters, and great blue herons. However, the continued protection of the river is integral to making sure these positive changes last!
The (ongoing) Colquitz River restoration project, launched by Peninsula Streams and the District of Saanich in 2019, aims to restore ecological integrity and resilience to this urban watershed system.
Scroll below or click the link here to view a story map created by UVic Community Mapping showcasing the restoration done to date within the Colquitz River in Copley Park.
"Working to Restore the Freshwater and Marine Ecosystems in Saanich" on page 6 of the Saanich newsletter "Our Backyard" by PSS Senior Aquatic Biologist, Katrina Adams.
Link to Our Backyard winter 2024 edition
Check out more of Katrina's work on the Colquitz in a video put out by the District of Saanich about the restoration work being done at East Copley Park.
Colquitz River Restoration at East Copley Park