By: Mike Anderson

A recent report from the Lake Simcoe Region Conservation Authority (LSRCA) states that Lake Simcoe’s phosphorous loads spiked at 131 tonnes in 2017.

That’s up from 73 tonnes in 2016, and significantly higher than the target of 44 tonnes set out in the Lake Simcoe Protection Plan (LSPP) in 2009.

According to LSRCA, annual phosphorus loads – the amount of phosphorus entering the lake from all sources — are used to help assess the health of the lake and how it’s changing over time. For instance, too much phosphorus can cause serious issues, including excessive plant and algae growth.

Graphic courtesy of LSRCA

LSCRA says 2017 was a wetter than average year, which may account for the high phosphorous loads: “More rain and snow means more flow into the rivers and ultimately the Lake.”


While LSRCA acknowledges the levels are higher than expected, it says the news isn’t all bad.

Oxygen levels are trending higher, which is good for a healthy coldwater fishery – however, LSRCA cannot explain why they remain positive despite an increase in phosphorus loads. It says more research is required.

“Targets set out in the Lake Simcoe Protection Plan identified an annual phosphorus load target of 44 tonnes, but that number was aspirational,” says Mike Walters, LSRCA’s CAO, in a recent media release.

“Forty-four tonnes was chosen because it was understood to be the phosphorus load necessary to achieve another, more critical target of 7 mg/L dissolved oxygen levels.

What we’ve learned is that despite higher phosphorus loads measured, we’ve actually surpassed the dissolved oxygen target. Oxygen is the more important measure because we know how dependent fish are on cold, clean, oxygen-rich water.”

However, not everyone agrees with the LSRCA’s interpretation of the results.

Jack Gibbons, Chair of Lake Simcoe Watch, calls the results “unacceptable.” “We are going backwards, not forwards,” he says.

According to Mr. Gibbons, Lake Simcoe’s average annual phosphorus pollution during the past three years (97 tonnes per year) has risen by 11 per cent relative to the previous three-year average (86 tonnes per year).

Mr. Gibbons is calling on the provincial government and specifically, local MPP Caroline Mulroney, Minister of Transportation, to help find a solution.

“In 2009 the Government of Ontario’s Lake Simcoe Protection Plan called for Lake Simcoe’s phosphorus pollution to be reduced to 44 tonnes per year. Unfortunately, Premier Ford’s Government does not have a plan or a budget to reduce Lake Simcoe’s phosphorus pollution to 44 tonnes per year,” he says.

“It is time for Caroline Mulroney to provide the strong leadership we need to reduce Lake Simcoe’s phosphorus pollution to 44 tonnes per year by 2026.”

Reaction was also swift from MP Scot Davidson, who issued a media release following LSRCA’s report.

Mr. Davidson is calling on the Liberal government to immediately re-start the Lake Simcoe Clean-Up Fund, which the Liberal’s promised to do during the last federal election campaign.

“It’s clear from this report that the heightened levels of phosphorous in Lake Simcoe can be directly attributed to the cancellation of the Lake Simcoe Clean-Up Fund,” says Mr. Davidson in the release.

“Over ten years, the Clean-Up Fund prevented an estimated 27,800 kilograms (roughly 27.8 tonnes) of phosphorus from entering the lake. This was achieved through innovative projects supported by the Clean-Up Fund that specifically targeted phosphorus reduction.”

LSRCA is also calling on the federal government to uphold its commitment to provide $40 million to clean-up Lake Simcoe:

“Access to that level of financial support will enable organizations like ours to continue the much-needed research and on-the-ground projects to address phosphorus and a host of other impacts to the Lake.”



  1. There are many things that add to the phosphorus levels of our precious lake.
    Below, I have lightly touched on some of these many examples.
    I wish something could be done about these problems, but who is going to stop it?
    Probably no one? ?‍♀️
    It seems that any “Powers to be” just find a band-aid solution, or some temporary solution.
    Companies that are supposed to be responsible for this sort of thing, just seem to spend their funds on pamphlets, or public education and don’t do enough to address MOST of these problems.
    Yes, it is something, but it really does NOT address these problems and it seems that so far, not much is ever really done unfortunately. At least, not enough to really help.
    1. Something has to be done about the Beaverton market garden fields!
    After the last heavy rain, we witnessed backhoes digging around in the muck in the fields and there was a lot of running water from these fields just pouring in the ditches.
    Seems like the wrong time to be doing this?
    The main ditches were FULL of a lot of mucky water that could run freely and steadily into the lake at Centennial Park.
    I mean A LOT! AND the water was dark brown! The effluent stunk!
    I had thought that there was already something done so that this would not happen?
    The “berms” that were apparently made to prevent this obviously were not working.
    Can’t everyone see this?
    2. I would also like to address the fact that over-use of septic systems happens frequently along shorelines of Lake Simcoe. It is very common to see many cars parked along roads near particular old cottages and MANY people there EVERY weekend!
    Don’t people realize that sewage has to go somewhere when septic systems are over used?
    How do these septic systems even pass inspection?
    Also, some septic pumping companies spread human waste directly onto farmer’s fields!
    As if that would never run into nearby ditches when it rains or snow melts? ?‍♀️
    3. There are MANY farmers fields in which hedge rows have been completely removed to allow more yield of crops. This too allows many chemicals to mix with water and that in turn, drains freely into nearby ditches that find their way to the lake.
    4. Livestock excrement also makes a problem for the water quality of the lake.
    Keeping livestock too close to nearby ditches should not be allowed.
    5. Overuse of lawn chemicals. Ya….we have all heard how the “new” lawn products and lawn care companies are using “safe” products to produce weed-free lawns. But are they safe?
    ANYTHING that promotes “healthy” growth of any plants, including lawns can also leech into the lake during rains and snow melting.
    6. I do support the cull of cormorants whose excrement is toxic and most certainly effects water quality in Lake Simcoe. There are those who do not agree, but it has been my experience that these people just do not know much about them. They only see them fly and swim. They have not witnessed fully what destruction they do and how they effect water quality or the Sports fishing industry.
    Some of the things I mentioned above could also potentially effect water quality in wells or municipal water. Funny….no one ever addresses this.
    There are many things that should be done in order to save our lake.
    But I ask – how would anyone “Clean-up” the lake? You can’t filter it easily. You can’t keep an eye on everything all at once.
    I suggest that something be put into place by lawmakers, and that some of these things are stopped completely. The sources of phosphorus are many.
    There should be more money allotted through the Provincial, Federal Governments and Municipal governments for actual fixing the problems, not for more paper pushing!
    Real money has to be spent on upgrading septic systems, (maybe again allowing the LSRCA’s funding to help with that).
    Fix the problems that are allowing effluent to freely run into ditches and into the lake by making permanent solutions.
    Stop the destruction of hedge rows which should not be allowed to be removed completely.
    Lawn care chemicals should not be allowed anywhere near the Lake Simcoe Watershed.
    Keep livestock back from nearby waterways by providing funding for fences and/or some sort of barriers that do not allow their excrement to run into nearby ditches.
    Stop the spreading of human waste on farmer’s fields by local sewage removal companies.
    Although I have lightly touched on SOME of the problems that add to the phosphorus levels on Lake Simcoe (and other lakes, rivers, streams, waterways), something has to be done and done quickly.
    I have written this in hopes that SOMETHING will be done. Any one of these problems should be addressed and fixed in any given year as time and money allows.


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