Steelhead trout have had a rough time of it in the Coquihalla River since 2014.
That’s when a remnant railway bridge abutment and historic railway bed that made up the popular B.C. Parks trail located in Coquihalla Canyon Provincial Park near Hope partially collapsed and slid into the Coquihalla River.
“The slide was about 16 feet tall, and even though steelhead are the Olympic athletes of the fish world, even they couldn’t make that jump as they tried to get upstream to where they needed to spawn,” said Shaun Hollingsworth, a volunteer with the Seymour Salmonid Society.
The society took an interest in the slide soon after it happened and put together a working group that included six levels of government (including First Nations governments).
Together they moved forward to gain some knowledge and expertise in rock removal in order to alleviate the situation.
“If you get a slide like this in a remote location, you’d just go in there with dynamite and remove it. Here we had a proximity situation where the trails and the popularity of the area to hikers didn’t make traditional blasting feasible,” Hollingsworth explained.
The answer was found in a product called NXBurst.
“This is a low-velocity explosive that is really more like a fast-expanding grout. You drill holes in the rocks you want to remove and then use this product.
“It still blows the rock apart pretty suddenly, but it isn’t nearly as violent as dynamite,” Hollingsworth said.
The activity was largely water-, weather- and safety-dependent but resulted in rock pieces that are small enough to be moved hydraulically downstream during the annual high-water events on the river.
BC Parks and the Ministry of Forests, Lands, Natural Resource Operations and Rural Development (MFLNRO) provided their expertise to oversee the work and to ensure that works were completed in accordance with standards and best practices for in-stream works.
A portion of Coquihalla Canyon Provincial Park had to be closed to visitors during portions of the proposed project, but the use of the low-velocity fracturing agent limited disruption while retaining the stability of the surrounding area and integrity of the in-stream habitat.
When Holllingsworth first heard about the slide and the problem the steelhead were having, there was a shortage of funding for any remedial work but, Jackie Tegart, MLA for Fraser-Nicola, was the co-chair of the Steelhead Futures Caucus at the time and was able to access some $90,000 for the work.
Funding for the project was provided by the Habitat Conservation Trust Foundation, the Freshwater Fisheries Society of BC, the Steelhead Society, and the Ministry of Fish, Land and Natural Resources. Overall coordination of the project was provided by the BC Conservation Foundation.
“We couldn’t have done it without Jackie Tegart’s help,” Hollingsworth said. “She was the one who really got things moving.”
In a final twist, Hollingsworth said the workers had to be careful not to do too good a job in removing barriers in the river.
“We didn’t want to flatten it out to a greater degree than it had been before. The barrier now is only about six feet, and steelhead can make that jump easily.
“Coho and other fish species can’t and that’s fine since this is not an area where they traditionally spawned.
“If we did too good a job, we ran the risk of introducing those fish into the area and they would actually be an invasive species in this spawning area. That would have been detrimental to the steelhead as well.”