Fish survive in Bears Creek, despite water quality that degrades as the stream travels through the urban environment
Will Pearson  - 
October 5, 2021

This spring, I walked along a portion of Bears Creek with Dylan Radcliffe, an avid naturalist and water resources technician.

Bears Creek originates in the Township of Selwyn, in a provincially significant wetland that straddles either side of County Road 19. It enters the city near Hilliard Street, and then cascades down through the Edmison Heights neighbourhood before joining the Otonabee River just south of Marina Boulevard.

At one point during our walk, Radcliffe wondered aloud what fish might live in the creek, a question which caught me off guard. I’d have guessed that no fish could navigate the culverts and other infrastructure that interrupt the creek’s flow.

Apparently, I’d have guessed wrong. “Fish can get into all sorts of surprising places,” Radcliffe told me. Even though he was the expert between the two of us, I was skeptical.

But a draft watershed characterization report prepared for the City of Peterborough last year confirms that three species of fish are known to live in Bears Creek. And later in the spring, I returned to the creek where it runs through a ditch alongside the parking lot of the Northcrest Plaza. There, next to a discarded Tim Hortons coffee cup and a plastic grocery bag flowing with the current, a fish was flopping on some rocks in a secluded and shaded portion of the creek.

The fins of a creek chub caught between some rocks in Bears Creek.

I photographed the fish, which was about six inches long, as it fought to free itself from the rocks. But it quickly swam away from me, retreating to a hiding place behind some tree branches.

My photographs were grainy and blurry, mostly featuring a hard-to-make-out Unidentified Swimming Object. But I sent them to Radcliffe anyway. “Creek chub I think,” he texted back. One of the three species identified in last year’s watershed report.

Finding a fish in this litter-strewn ditch, where the bank is constrained by a chain link fence on one side and by a parking lot on the other, was thrilling for me.

I had already been exploring Peterborough’s creeks for a month or two. But now they opened up a whole new side of themselves. They weren’t just aesthetically pleasing conveyances of water. They were ecosystems.

And fragile ones at that, I came to learn. “Most urban creeks are not healthy creeks,” Hayley Goodchild of Peterborough GreenUP told me. That’s for two main reasons, she said. First, they are often engineered to have hard rather than natural banks. Once forced into a concrete channel or culvert, creeks are deprived of the vegetation and animal life that would otherwise live along their banks and help to keep them healthy. Second, urban creeks take on the stormwater that runs off of our city’s paved surfaces. That stormwater can introduce pollutants, raise water temperatures, and cause erosion.

Last year’s draft watershed report assessed the health of each of Peterborough’s 18 subwatersheds according to a variety of metrics. It found the urban portion of Bears Creek to have “poor” aquatic health, and it recommended the Bears Creek subwatershed as a high priority for remediation.

The report noted “decreasing water quality as the creek progressed downstream. This likely represented impacts from urban development including sedimentation and nutrient inputs from adjacent landuse.”

Bears Creek enters this culvert on the west side of Hilliard Street …
… and then exits on the east side of Hilliard into a sleepy, wooded area.

After entering Peterborough’s city limits and crossing under Hilliard Street, Bears Creek spills down into a ravine north of Hilliard between Franklin Drive and the Parkway Trail. Much of this ravine is hidden below street level, but those who venture down its slopes find a hidden green gem for the city’s north end — the Bears Creek Woods. 

When I visited the Bears Creek Woods with Radcliffe, he noted the silty nature of the soil on either side of the creek, indicating a significant runoff had happened in the woods recently.

Dylan Radcliffe in the Bears Creek Woods in April 2021.

Bears Creek is a “flashy” stream, Radcliffe continued, which means its water volume swells quickly whenever there is rainfall. 

“A flashy watershed is one that has a high degree of impermeable surfaces, like roadways, parking lots, roof tops, those sorts of things,” he said. “So water from rainfall events falls on those surfaces and instantly runs off into the closest waterway.”

Urban development upstream of the woods, including the Mason Homes Parklands subdivision, is the culprit, Radcliffe said. The impermeable surfaces in these developments deflect rainwater instead of soaking it up, sending the runoff into the stream and through the woods, he said.

To get a better sense of how housing development has encroached on all sides of the Bears Creek Woods, compare the City of Peterborough’s historical and contemporary aerial imagery. Slide to toggle the image below between 1962 and 2020:

Before Image After Image

The City’s aerial imagery shows the enduring presence of the Bears Creek Woods ravine, but in other places, the imagery reveals how the stream has been diverted to suit urban development.

For example, Bears Creek exits the ravine through a culvert that carries it below a low-rise housing complex — the Briarlane townhouses. It emerges from the culvert on the other side of the townhouses and then swerves to avoid the Northcrest Plaza parking lot. But it didn’t always follow this route.

The aerial imagery shows the creek used to travel straight through where the parking lot is now. It was diverted sometime in the late 1960s or early 1970s, bent into an unnatural shape, including two right angles that the watershed report calls “hydraulically inefficient and prone to erosion.”

Slide to toggle the image below of the Northcrest Plaza and its parking lot between 1956 and 2020.

Before Image After Image

After its diverted path around Northcrest Plaza, Bears Creek swings eastward to travel alongside Marina Boulevard. Soon after, it tunnels underground in a series of culverts.

Bears Creek along Marina Boulevard, after passing Northcrest Plaza.
A culvert conveys Bears Creek under a Marina Boulevard driveway.

After flowing underground along Marina Boulevard, Bears Creek emerges on the south side of the roadway, across the street from Edmison Heights Public School. It sneaks behind some backyards, and then tumbles down through the Bears Creek Gardens, which is the park across the street from Northcrest Arena.

Here, you can appreciate the efforts of the Otonabee Region Conservation Authority (ORCA), which has worked to naturalize some of the creek’s shorelines in the park. “We’ve done a lot of planting in Bears Creek Gardens,” Meredith Carter from ORCA told me. “There was quite a bit of erosion there, so with a number of school classes over the years we’ve replanted the shoreline buffer.”

Restoration initiatives such as this one, which replant native vegetation along creek banks, are beneficial in a few different ways, Carter explained. The plants’ roots help to solidify the banks, which decreases erosion risk. And the vegetation also purifies runoff as it flows toward the creek, so that by the time it reaches the watercourse, it’s cleaner. “It’s acting like a filter,” Carter said, “so any runoff coming towards the watercourse is going to get captured in that vegetated buffer.”

In the Bears Creek Gardens across the street from Northcrest Arena, naturalized shorelines buffer the creek.

Bears Creek was the first of Peterborough’s creeks whose route I walked in its entirety. Following its journey from the city limits to the Otonabee, I discovered new places, even as I walked through a neighbourhood I thought I was already familiar with.

This is a feeling Carter shared with me as well. “Bears is neat,” she said, “because it’s kind of hidden. It goes through some highly developed areas, and still has some lovely magical parts.”

Letting the creek guide me, my sense of the city started to shift. My mental map began to rely less on the sidewalks and roadways that previously defined it and more on the area’s natural features and terrain.

But at the creek’s terminus, these two mental maps converge. Like every other stream in Peterborough, Bears Creek’s destination is the Otonabee River, which it reaches after flowing underneath Water Street just south of Marina Boulevard. Like other motorists and transit riders, I’ve passed over the creek hundreds of times without realizing it.

Just before it reaches the Otonabee, Bears Creek travels underneath Water Street, funnelled through a concrete channel that is likely unnoticed by the motorists above.

And so one night this summer, I finally climbed down to get a view of this crossing from the creek’s perspective. I found a square channel for the creek cut into the roadway’s concrete infrastructure — a somewhat undignified ending, I thought, for such a pretty creek.

Photos and map by Will Pearson.

This article is the first in Creek Week, a series about the creeks and subwatersheds of Peterborough. As more articles get posted, you’ll be able to find them here.