Have you ever wondered whether the Cowichan River is safe for swimming?

I certainly have.

After all, we’ve heard a lot about “beach advisories” this summer on southern Vancouver Island that recommend against recreational water use, including swimming, due to fecal contamination or blue-green algae.

The public advisories issued by Island Health in North Cowichan to date this summer have included Fuller Lake in Chemainus, Maple Bay boat launch, and a long-standing advisory for Art Mann Park at Quamichan Lake.

But no information on the Cowichan River, even though it is a popular swimming destination, including at Sandy Pool Regional Park, Vimy beach near Heritage Road, and in the slow-moving lower reaches near the City of Duncan.

Importantly, the Town of Lake Cowichan also operates a sewage/wastewater treatment plant in the upper river which has come under scrutiny for violating its Environmental Management Act permit.

As recently as May 27 this year, the town received an “out of compliance warning” for repeatedly exceeding its maximum allowable discharge limits, according to the province’s compliance and enforcement database.

(Read more: https://www.sixmountains.ca/article/f29d52a9-3b52-488e-ae61-4b75c936b08a )

Beach advisories can be issued when sampling exceeds 200 E. coli or 35 enterococci per 100-millilitre sample.

So, is the Cowichan River safe for swimming or not?

Resolving that question proved more difficult than you might think.

Island Health said it “does not conduct regular beach sampling along the Cowichan River.”

The Cowichan Valley Regional District (CVRD) said the focus of multi-agency monitoring in the river has been on “parameters that directly affect fish health (temperature, dissolved oxygen, pH) rather than on factors affecting recreational use of the river.”

Finally, I contacted the Cowichan Watershed Board, where communications director Jill Thompson put me in touch with Tom Rutherford, director of strategic priorities.

Rutherford explained that the board is part of a collaborative effort that includes the Ministry of Water, Land and Resource Stewardship, Cowichan Tribes, and CVRD that came together in response to the 2023 fish mortality event on the Cowichan River.

The group has installed and operated six continuous monitoring stations on the Cowichan from the upper waters down to the confluence with Somenos Creek.

The data is downloaded weekly and there is a Monday morning "situation room" meeting with representatives from all the partners, Rutherford said.

They look at the data and make decisions on how to respond in terms of adjusting water release, effluent release, angling opportunities, etc., in order to minimize impacts to fish and aquatic ecosystems.

While this continuous monitoring network does not include biological sampling, the ministry obtained funding from the Habitat Conservation Trust Foundation to take samples at the same six locations to look for nitrogen and phosphorus, as well as E. coli.

The results are good for swimmers. Sampling on July 2, for example, showed just four E. coli units at Sandy Pool compared with 25 units at Rotary Park just downstream of the silver bridge on the Trans Canada Highway, where dog feces could be a factor.

That's well below the threshold for sounding the summer alarm for human health concerns.

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— Larry Pynn, July 28, 2025