Chilliwack looks to uncover hidden streams

The city is creating a formal system to 'daylight' the watercourses currently moving through pipes and culverts

Author

Grace Kennedy
May 06, 2025

The City of Chilliwack is taking a more formal approach to replacing its culverts and pipes with open streams. 📷 City of Chilliwack/Facebook

This story first appeared in the May 6 edition of the Fraser Valley Current newsletter. Subscribe for free to get Fraser Valley news in your email every weekday morning.

Chilliwack wants to bring its underground streams into the light, and it's not the only Fraser Valley community looking to do so.

The Fraser Valley was once full of meandering streams and intertwining watercourses. But as settlers began to reshape the region for farming, and as developers paved over fields to build houses, the valley’s natural streams were turned into narrow ditches, or pushed underground into pipes culverts.

Today, the City of Chilliwack is beginning the process of bringing at least some of those pipe-bound streams to the surface.

The process—known as ‘daylighting’—brings positive environmental benefits to the region, by establishing riparian habitat, promoting groundwater filtration, and replenishing aquifers. But daylighting isn’t entirely altruistic.

In a council meeting earlier this year, Chilliwack staff noted that many of the pipes and culverts that kept local streams below ground are beginning to fail due to age—storm pipes have a lifespan between 20 and 70 years, and it’s not clear when some of Chilliwack’s pipes were installed.

In some places, particularly rural areas like Greendale or Yarrow, the city doesn’t know a pipe needs replacing until a sinkhole forms above or flooding occurs.

The city does not have enough money in its culvert replacement budget to fix the unexpectedly failing pipes, according to a staff report. (Staff said it cost around $3,000 a metre to have a contractor replace a pipe, while it only costs around $300 a metre to have city staff open the watercourse.)

It has been the city’s unofficial policy to restore underground channels into natural watercourses when possible, creating open streams and small riparian areas instead of simply replacing the culverts.

Now, the city is looking to take a more formal approach to opening the streams—and hopefully doing so before sinkholes form.

Coun. Chris Kloot said he had concerns that ditches created to bring water to farms might be characterized as fish-bearing streams.

“It could be used as drainage today … but in a very short period of time, it will be classified—at some point, outside of our control—as a fish-bearing or protected species watercourse,” he said.

Changing legislation on riparian setbacks for fish-bearing streams could have an impact on people with those watercourses near their homes, Kloot said. He wanted to potentially include a cost-sharing option for property owners who may want to keep pipes beneath their yard, rather than recreate a stream.

An official policy is still in the works, and would cover roughly 8km of covered ditches on municipal land, largely in neighbourhoods like Greendale and Yarrow. The policy would likely give homeowners the option to keep their pipes and culverts, if they pay the difference between daylighting and pipe replacement. (Chilliwack council went back and forth on when, exactly, that option would be appropriate, given how expensive pipe replacement is.)

Chilliwack isn’t the only community daylighting its underground waterways.

The City of Abbotsford is daylighting streams in its tentative Mill Lake Park plans. Council has indicated support for a plan that would see a portion of the Willband Creek uncovered. Currently, 900 metres of the watercourse is enclosed within the city’s stormwater and sewer systems. The city’s most recent Mill Lake concept included replacing a culvert that drains water east toward Ravine Park with a restored stream, at least within the park boundaries.

Mission’s Environmental Charter also includes policies for daylighting watercourses; staff began work to review its streams and ditches and draft a policy for removing culverts last year. In January, staff identified Horne Creek and Lane Creek as possible places where the watercourse could be opened up.

Langley City is also looking to expose its streams; its official community plan specifically states that daylighting should be considered in site planning. In Metro Vancouver more broadly, removing unnecessary stormwater pipes is part of the region’s Climate 2050 Roadmap, and Vancouver itself has work underway to uncover its “lost” streams.

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