The work may have blocked locals from the beach for a few months, but the result unblocked salmon from valuable rearing and spawning grounds for lifetimes.
The Pacific Rim National Park has wrapped up a $1.7 million restoration project that will allow fish to flow freely through Sandhill Creek underneath Wick Road. Wick Road was closed through the spring while a corroded and undersized culvert was replaced with a free-span bridge and a stream was ecologically engineered to flow underneath.
“As far as we can tell, it was the single best improvement in [local] stream ecosystem health that has been achieved in the past decade or more,” Pacific Rim National Park ecologist Yuri Zharikov told the Westerly adding the late Bob Redhead was instrumental in getting the project off the ground.
“The person who led this effort from the get-go was Bob Redhead. He was the champion and the driver behind this process…Bob Redhead was pivotal in achieving what we have achieved.”
As part of one of the largest stream systems on the peninsula, Sandhill Creek plays a vital role in the West Coast’s environmental health.
It allows salmonids to access rearing and spawning grounds, helps keep wildlife like bears, otters and eagles that rely on these salmonids well nourished and provides a food source for smaller animals that feast on the scraps larger animals pull from the stream and leave behind.
“Most of Sandhill flows through still-undisturbed forest and that’s the conditions that persisted in this area prior to industrial logging, development, road building and everything else that’s happened here in the past century,” Zharikov said.
“Overall, this area was known as the ‘salmon factory’ and that speaks to its flat landscape and low rates of flow in the streams that allows fish to migrate long distances and to spawn successfully when they get into these systems.”
Zharikov added the salmon that swim through Sandhill bring in nitrogen which creates stronger forests.
“Importantly, they grow the forests themselves,” he said. “Trees growing around streams, to a large extent consume nitrogen that is derived from the ocean and that’s the nitrogen that the salmon physically bring into the streams and into the forest systems and allows the trees to consume it and grow bigger.”
When Wick Road was constructed prior to the Park’s establishment in the 1970’s, it landed on Sandhill Creek, roughly 400 metres from Hwy. 4, and a culvert was installed to allow salmon to continue traveling through.
This hanging culvert—a culvert suspended above the downstream water’s surface—though was undersized making its discharge during heavy rainfall too massive for fish traveling upstream to battle through and, because of its elevation, young salmon were unable to travel through it during dry periods.
In addition, Zharikov said, the artificial waterfalls created by the hanging culvert created deep pools that became “ecological traps” for young salmon trying to get downstream.
“They ended up in the deep pool and they were consumed by sculpins, which is a major predator of juvenile salmonids in freshwater ecosystems,” he said. “That particular arrangement created extremely favourable conditions for these sculpins to simply sit there and wait for young salmonids, or anything else, to be brought through the current down through the culvert.”
Zharikov said Park staff, along with the Department of Fisheries and Oceans Canada, investigated the Wick Road culvert in 1999 and realized it was heavily corroded and significantly smaller than it needed to be to serve a stream Sandhill’s size.
“Having a large swath of the landscape essentially blocked, as far as fish passage, seemed counterintuitive to our mandate and certainly counter to how we position ourselves as both a protection and restoration agency,” he said.
“What it boiled down to was the resources required for the project of that scope and size…Everybody realized that, to make a meaningful and lasting restoration contribution to the ecosystem health, it would need to be something bigger than just trying to patch up the existing culvert.”
The resources required for a large-scale restoration project became available through 2014’s federal budget and, after engineering assessments were done, a plan of attack was determined. Rather than replace the existing culvert with a larger one, a free-span bridge was created to allow unblocked passage through a stream habitat created underneath.
Work kicked off at the start of 2016 and, with the bridge and stream now complete, Zharikov believes fish access has been restored to what it was prior to the road’s construction roughly 50 years ago.
“The area underneath the bridge was ecologically engineered to resemble a natural stream that would be passable to any fish, adult or juvenile, at any point,” he said. “To me it is exhilarating…Now you have a free span bridge with a natural looking stream flowing underneath without any restrictions to the way and the rate of its flow.”
He added Park staff worked with the Central Westcoast Forest Society to restore the ecological integrity both upstream and downstream to remove any lingering sculpin traps.
Zharikov said he’s excited to see coho swimming under the bridge and entering the tributaries upstream this November.
“Being able to see fish moving freely under the bridge, that’s the greatest reward, I think, for both us as the responsible agency and any local resident or visitor who cares about salmon and the environment in general,” he said.
He said Park staff will monitor the area and research the project’s impact on the ecosystem.
“We will be able to say exactly how many more fish are using the area and how it improved their productivity,” he said.