Delta’s Cougar Creek to get five weirs for spawning salmon

Delta’s Cougar Creek to get five weirs for spawning salmon

The Cougar Creek Streamkeepers spent a week building the barriers

The Cougar Creek Streamkeepers have spent a week doing construction down at Lower Cougar Creek to make it a better place for spawning salmon.

The streamkeepers have constructed five weirs, horizontal barriers across a waterway, along Lower Cougar Creek to increase depth of the pools behind the weirs and oxygenate the water passing over them.

“These are mainly for chum salmon,” said Bob Scanlon, the instream habitat coordinator for the streamkeepers. “Chum salmon like to spawn in low gradient, slower water. They’re kind of lazy fish — and they’ll love this area down in here.”

He looked over at the weir he was building with fellow streamkeeper Pete Willows.The water was already starting to pool behind the rock, and a trickle flowed over the barrier. Undergrowth drooped over the edges of the bank.

Weirs are a natural stream feature — although these ones are man-made — and can be made by falling logs, rock piles or even beaver dams.

“Back in the old days, it was the beavers who often made impoundments in the water,” streamkeeper Deborah Jones said. “But now we don’t have enough trees to allow beavers to just be cutting everything down.”

The pools act, not only as a refuge for fish, but also a place where smooth pebbles can pile up, creating an ideal spot for salmon eggs.

Related: Delta to ‘rename’ Northeast Interceptor Canal to Lower Cougar Creek

The rock for three weirs was donated by the Corporation of Delta, and additional rock for another two was found already in the stream.

Now is the ideal time for the streamkeepers to build the weirs. It is what is known as “fishery time,” a part of the year when the small fry are moving out of the river, and don’t mind a little habitat disruption.

Spawning salmon won’t start to be moving up the Fraser River and into Cougar Creek until late October.

“There are probably scores of salmon at the mouth of the Fraser,” Willows said.

“But they’re waiting for some cooler water,” Scanlon added. “The water’s too warm in the Fraser right now.”

This year, Cougar Creek will see mostly coho salmon — an active, shy salmon that prefers the swift waters in Cougar Canyon. But it’s possible that some of the gregarious, lazy chum salmon will return this year too.

“We won’t be getting a lot of chum actually until next year,” Scanlon said. The streamkeepers have been releasing 150,000 fry a year, and next year will be the first return of those fish.

Scanlon is expecting 500 chum next year, but wouldn’t be surprised to see 3,000 make their way up the stream.

“It’s probably not going to happen, but who knows.”