Technician Report – Tuesday, September 28th

Happy Technician Tuesday! Earlier this year, our technician team surveyed Glen Urquhart stream to assess its profile for future stream restoration projects. While Glen Urquhart has been highly modified and impacted, salmon and other fish species do utilize it. Improved habitat in this area will directly benefit those species.

The main data collected was depth, width, high water marks, sediment type, presence of invasive species, and areas for improvement. These qualities were measured every ten meters along the stream. The physical features of the stream (depth, width, high water marks, etc) were then graphed to give a stream profile diagram. This diagram will help us identify the types of restoration that would be beneficial and areas where it is most needed.  

For instance, Glen Urquhart collects a large amount of water because the surrounding area has large impermeable surfaces, like concrete, as it is an urban stream. When the water load is high, it causes high flows and turbidity which wash away sediment and increase erosion. Essential gravel substrate for salmon spawning can be lost during these periods. Our profile diagram will help identify the areas where restoration projects designed to slow down flows and retain spawning sediment are most beneficial.  

Yellow flag iris was found at Glen Urquhart during the stream survey. Yellow flag iris is an issue in wetland areas. It spreads quickly via rhizomes and outcompetes other plants. It also causes a barrier to fish movement if it establishes in the center of the stream. Removal of yellow flag iris is tricky, because if pieces of the plant are left behind it can reestablish itself. These pieces can also travel downstream, creating a larger distribution of the plant. At Glen Urquart it was found in small enough numbers that we could gently pull whole plants out of the stream. 

If you find yellow flag iris in the community, you can report your sightings on iNaturalist. If it is located on your property, please consider careful removal to prevent further spread. More details can be found on the Invasive Species Council of BC (ISCBC) website.