Discarded Christmas trees used to restore creeks and streams, protect fish in Halton

Trees rebuild banks in creeks, streams in order to reduce warming of the water

Posted: January 04, 2019

Kent Rundle, left, and Alex Meeker stand by Bronte Creek in Carlisle, Ont., where they've worked to narrow the creek banks and cool the water to help local fish. (Taylor Simmons/CBC)

Although the holidays are over, Conservation Halton is just beginning to stockpile hundreds of Christmas trees.

They're an important resource for restoration efforts in the region, with the conservation authority using the discarded trees to narrow over widened creeks and streams and, in turn, protect local wildlife.

"With an over-widened creek, we have a greater surface area for the sun to warm up the water, and when this water is very, very warm, it's not habitable to sensitive species," said Kent Rundle, watershed stewardship co-ordinator with Conservation Halton.

Conservation Halton gathers hundreds of Christmas trees just after the holidays so they can be added to creeks and streams in the summer. (Conservation Halton)

Each year after Christmas, the conservation authority works with corporate partners, tree nurseries and municipal waste-disposal departments to gather hundreds of trees, many of which would have otherwise been burned or ended up in a landfill.

The conservation authority began using Christmas trees about six years ago to begin narrowing and cooling watersheds around the region.

Extending creek and streambanks​

The installation of Christmas trees typically begins in the summer.

"We tie the Christmas trees together using a biodegradable twine and we anchor them into the bed of the creek and the bank of the creek," Rundle said.


"Creeks carry a lot of sediment with them. The sediment will naturally get trapped in the Christmas trees, creating an earthen bank that we then grow up with trees and other plants so we get a natural habitat and a narrower creek."

The many bristled branches and needles on the trees are perfect for catching the passing sediment, and they're a natural addition to the water.

Conservation Halton adds "sediment mats" to the banks of creeks and streams. (Conservation Halton)

"I'm not entirely sure how the concept came to be, but my guess would be imitating natural processes," Rundle said.

"Trees fall down into the creek all the time. They deflect flows and probably they were saying, 'Wow, sediment is naturally depositing here. We can mimic this.'"

Cooling Bronte Creek

Courtcliffe Park is one of the main beneficiaries of the Christmas trees.

Conservation Halton started adding the trees to Bronte Creek, which runs through the area, in 2015.


From the 1970s to 1990s, the area housed a trailer park and the owners dug out large portions of the creek, according to the conservation authority.

"We believe it may have been widened by as much as five times its historical width," said Rundle.

According to Conservation Halton, a trailer park co-op existed around Bronte Creek from the 1970s to 1990s. The City of Hamilton purchased the land in 1998, and restoration work began. (Conservation Halton)

With a greater space to heat, the creek is warming, according to Alex Meeker, a monitoring and assessment biologist with Trout Unlimited Canada, a partner in the Christmas tree protect.

Warmer creeks are bad for local fish, including brook trout, a cold-water fish found in Ontario. They need water temperatures to be less than about 18 C in order to thrive.

"Brook trout are kind of known as canaries in the coal mine, so if brook trout are happy and the water is cold enough for them then we're actually helping to protect a whole range of species, as well," Meeker said.

Narrowing the creek also allows the water to pick up speed, she said, which creates better habitat conditions for fish.


Conservation Halton has also used Christmas trees to build more organic content and spaces for refuge in watersheds.

The Christmas trees are squished and tied together using biodegradable twine. They're then held in place by wooden stakes to collect passing sediment. (Conservation Halton)

Bronte Creek is now home to one of the largest "sediment mats" Conservation Halton has created, composed of between 150 and 200 Christmas trees, stretching 40 feet long and extending 20 feet into the creek.

It doesn't look like much in the winter, but Rundle said when it thaws, the results are visible.

"We've started to see earth on top of the Christmas trees and plants growing and we've even gone so far as to plant in some native shrubs here, as well, just to help accelerate the process," Rundle said.

"It works quite well."

So well, Halton isn't the only place using the technique.


Credit Valley Conservation also collects Christmas trees around this time of year to be used in installation projects in the coming summer. (Credit Valley Conservation)

Since 2008, Credit Valley Conservation has installed Christmas trees in the Upper Credit Conservation Area.

They've similarly used the trees to rebuild eroded banks and lower temperatures along a stretch of the the Credit River, which was previously used as a cattle pasture.

Credit Valley Conservation used Christmas trees to close large coves along the Upper Credit shoreline, which collected sediment and have now settled. (Credit Valley Conservation)

Since 2000, the Royal Botanical Garden has also used Christmas trees to create a blockade at the mouth of Grindstone Creek and Cootes Paradise in order to stop common carp, an invasive species that destroys natural habitats and creek beds in the area, from entering.

They're currently collecting Christmas trees (up until Jan. 14), as they reinstall the barrier each year.

The Royal Botanical Gardens is using donated Christmas trees to build and maintain a barrier that keeps invasive carp out of some of Hamilton's waterways. (Royal Botanical Gardens)

As for Halton, they're hoping to get 400 Christmas trees over the next few weeks for projects coming up this year.

If you'd like to help, rather than donations, they're asking for your time this summer when the installations begin.

"We love to have people come out," said Meeker. "The more the merrier."