New wetland salmon habitat to help restore floodplain by Okanagan River

A project to create a new rearing habitat for chinook salmon along the Okanagan River is almost finished.

To create the new wetland for salmon, Osoyoos Indian Band and the Okanagan Nation Alliance (ONA) excavated roughly 7,300 square metres of the Vaseux floodplain — a wetland area upstream of Vaseux Lake by the river — in February and March.

Once complete, the pond will help restore the riparian wetland’s ecological functions in syilx territories. 

It’s part of the ONA’s plan to help restore wild salmon back to the nation’s waterways, and to bring the riparian wetland one step closer to its original ecological functions.

“Think of it as a nursery,” explained Kasey Moran, an ecologist and ecosystems project manager with the ONA. “It’s a place where they can get to be big and strong enough to make that journey out to the ocean.”

Roughly 20 kilometres south of snpink’tn (Penticton), the project is expected to have a pipe installed under the floodplain’s dike in August, finally connecting the pond to the Okanagan River. 

That culvert pipe will give young chinook salmon access to the new rearing habitat, where they can spend months sheltering, maturing and snacking on bugs. Currently, salmon hatch in the river before they swim to the Pacific Ocean, and eventually back.

“What we’re trying to provide them with is this area off that main channel, where they aren’t getting washed out,” Moran said.

Once the river is connected to the pond, Moran said that a future project might reconnect the pond with the river’s former natural channels that still exist throughout the wetland. 

“The goal is to make it so that the river can kind of heal itself,” she said.

“You would really need the entire river to be flowing through the wetland, in order for those cleaning and sediment-trapping functions to be restored.”

Decades of engineering heavily impacted water flow

Before settlers engineered the Okanagan River to make it straight — known as “channelization” — in the mid-20th century, the waterway slowly zigzagged and meandered through the valley, Moran explained.

Before it was channelized, the river once traveled through the wetlands of the Vaseux floodplain, naturally splitting off into smaller, separate waterways.

The wetland’s native plants — including cattail, bulrush and tules — would clean the flowing water by trapping and storing sediments such as fine silt, sand and clay.

“By the time it got to Vaseux Lake, the water would be clear and drinkable,” Moran said.

But when the river was straightened and dike embankments added — to control its flow and prevent flooding — the once slow-moving, meandering waterway turned into a fast-flowing river.

In an attempt to slow down the water’s flow, eventually planners installed a series of vertical drop structures — akin to speed bumps for water — along the river’s route. 

But attempts to control the water flowing through the Okanagan River came with a cost.

“The fish can’t get past those easily,” Moran said.

To make matters worse, settlers also dumped agricultural fill around the Vaseux floodplain so the land could be farmed, she added.

‘Wetlands are the kidneys of river systems’

The dike currently in place between the floodplain and the river doesn’t actually prevent water from overflowing the river banks, Moran said.

Instead, the dike prevents both fish and water from flowing through the area naturally.

“It’s disconnecting the ecosystems,” she said. “It’s disconnecting these wet, marshy floodplain ecosystems from the river. They should all be connected.”

Since the river was channelized, she added, it has become “just like a pipe,” pumping large numbers of fish and harmful sediments into Vaseux Lake.

“The water moves right through, and there’s no capturing sediment,” she explained. “There’s no cleaning of anything as it moves through that area.”

Pollutants being dumped into the lake from the river has harmed both water quality and fish survival rates.

Contaminants flowing into the lake caused algae blooms that significantly disrupt aquatic ecosystems and pose a risk to water quality — impacting the health of humans, aquatic beings, and other wildlife, according to Watersheds Canada.

“The wetlands are the kidneys of river systems,” she added. “And we’ve disconnected the kidneys from the system here. 

“We’ve killed the kidneys, so we’re trying to bring them back.”

Wetlands ‘a grocery store and a pharmacy’

When the wetland’s restoration team excavated the pond earlier this year, they had to rid the Vaseux floodplain of invasive plants and weeds.

That’s partly because the area is “no longer as wet as it used to be,” Moran said, thanks to impacts of channelization and adding agricultural fill.

“It changed the types of plants that can survive there,” she explained, “so now these weeds are just thriving.”

In April, community members planted a variety of native plant species in the area, such as bulrush and cattail. Both plants play key roles in helping clean water flowing through them; they also act as attachment surfaces on which fish and amphibians can lay their eggs.

They also planted cottonwood and willow — two native riparian plants, in the wet soil above the open water, as well as wild rose, snowberry, chokecherry and hawthorn.

Moran said the project’s planners sought guidance about the wetland plans from syilx Knowledge Keepers, who told them “this area was really like a grocery store.”

“There was tons of food — it was a grocery store and a pharmacy.”

The excavated pond is now filled with groundwater, and is expected to fluctuate in depth from 20 cm up to 60 cm deep, depending on the low and high flows of the river. 

“It’s all one water, it’s all connected,” Moran explained. “It’s connected from the top of the mountains down to the valley bottom.”

She said that if you dug down in the area, the groundwater’s depth is similar in elevation to the nearby river surface.

“It’s all connected underground — it’s just continuously wet,” she said. “So when you dig down, it is the same water, but this was underground.”

The Vaseux floodplain re-engagement project mirrors another initiative upstream in snpinktn — the k’əmcənitkw Floodplain Re-engagement project — which was completed in 2022.

ONA also led that effort, alongside the En’owkin Centre and Penticton Indian Band. 

Similar to the Vaseux floodplain, the aim of k’əmcənitkw was “reconnecting the river to the last remaining contiguous piece of floodplain wetland in the Penticton area for the first time since the 1950s,” as noted by the South Okanagan Conservation Fund. 

Connecting the river to the k’əmcənitkw floodplain helped restore fish and wildlife habitat. And like the Vaseux floodplain, it serves as a rearing habitat for chinook salmon, too. 

The work done at the Vaseux and k’əmcənitkw wetlands speaks to a vision shared by late Okanagan Indian Band Chief Albert Saddleman in the 1990s —  “to put back the river, bring back the fish, and put back the people.”

“There’s the potential in the future to re-route the flow of water, so not having a channelized system anymore,” said Moran.

“Potentially — eventually — having the river once again meandering through a functioning wetland.”