Concerns for the Lake Simcoe Watershed

Why Are We Concerned?

Lake Simcoe’s ecosystem is in a precarious position, and that means the area’s $420 million per year sustainable outdoor recreation and tourism sector, and its jobs, are at risk too. The main environmental problems facing the lake are: phosphorus pollution, climate change, development and intensive paving/hardening of lands and the subsequent loss of forests and wetlands, urban stormwater run-off, road salt, and invasive species.

Phosphorus and Fish

The nutrient phosphorus is naturally occurring, and although is not toxic in and of itself, too much is a bad thing. Excess phosphorus reaches the watershed’s streams and the lake, and causes excessive algae and aquatic weed growth which, upon decomposition, ultimately triggers low oxygen levels in the water.

The Lake Simcoe science community uses the Lake Trout as an indicator species for lake health, meaning it is used to infer habitat conditions. For instance, the science behind the LSPP uses the Lake Trout’s dissolved oxygen needs to determine the lake’s phosphorus load target. Efforts to improve the lake’s health are helping, as our indicator species indicates; the Lake Trout is showing signs of recovery as phosphorus loads have come down since the 1980s and dissolved oxygen levels have come up. But phosphorus loads have not gone down in recent years. The Lake Simcoe Region Conservation Authority’s Phosphorus Update states, "While annual variations are apparent, the recent five-year average phosphorus load is consistent with the average of the last decade (2005/06- 2014/15; 85.8 tonnes) despite an increase in the urban area of the watershed.”

Efforts to bring down phosphorus loads appear to be just cancelling out the increased load from new development, urban and suburban areas.

Development Impacts

Development can affect the environment in two main ways: loss of natural lands or farmlands, and water quality impacts. Across Simcoe County and the Lake Simcoe watershed, forests and wetlands are being lost, largely to development and changing land uses on farms.

Development impacts on water quality stem from the loss of natural features and their pollution-filtering functions, increases in hardened impervious areas, leading to run-off, phosphorus loading associated with construction and polluted stormwater run-off, urban development and major infrastructure (eg. highways). Phosphorus from development activity is the only growing source of phosphorus entering the lake. Ontario’s Lake Simcoe Phosphorus Reduction Strategy says:

“Under the Plan all new developments are required to have enhanced stormwater management controls in place, subject to limited exceptions. Accounting for these controls, analysis indicates the phosphorus load from these new developments would be 15.3 T/yr. Additional analysis indicates that combining “Enhanced” stormwater management controls with LID [Low Impact Development] practices would reduce the phosphorus load from new development to 9.2 T/yr. While the Strategy and the Plan strongly encourage that effective measures are taken to mitigate and reduce phosphorus contributions from new development wherever possible, significant phosphorus loadings from development will occur and should be offset in some way.”

The Lake Simcoe Phosphorus Offset Program (LSPOP) goes some way to meeting this need by charging developers for the phosphorus loads coming from their developments, and spending the money on projects that restore water quality nearby. The Lake Simcoe Region Conservation Authority deserves credit for their leadership in advancing, and gaining support for, Phosphorus offsetting, Low Impact Development and stormwater management policies and programs. But the LSPOP is not a panacea. It is heavily bureaucratic, and it not guaranteed to succeed in the long run. LSPOP does not apply to all new development, and it assumes that in some cases the offset will be administered in perpetuity, which is highly optimistic.

The Low Impact Development programs which have been established in the Lake Simcoe watershed as a result of the Lake Simcoe Protection Plan are cutting edge in Ontario. We should not presuppose the outcomes, however, before we have evidence that these programs and techniques are working to protect water quality. Careful monitoring and adaptive management must guide development decisions in the watershed, so that ultimately the lake’s health is protected.

Climate Change and Lake Simcoe

The lake’s water is now staying warm longer at the end of summer, which affects freeze up. The lake is staying in its spring / summer state for a month longer than it used to in the 1980s, so the length of time the ice covers the lake is shorter than it used to be. In the Lake Simcoe watershed, annual air temperatures have already increased 1.6°C from 1980 to 2012. Data suggests that over the next 40 years there will be an average mean temperature increase of 2.5 to 3°C and an increase in annual levels of precipitation in the order of 10%. The changes described stress the lake’s delicate ecosystem and its wild inhabitants, and put Lake Simcoe’s significant ice fishing industry on thin ice.

While we may not solve climate change, we must take steps to mitigate and adapt to a changing climate. Increased forest cover may help mitigate the effect of urban heat islands in communities around the lake, while forests, and in particular, wetlands, can help slow and cool urban run-off and run-off from major precipitation events and reduce the financial costs of floods by up to 38 percent.

We Can Do This

At the moment there is no substantial evidence that Lake Simcoe’s overall health is improving, though some indicators are promising. The status quo is hurting Ontario’s water quality, reducing farmland and natural cover, and limiting our options for a sustainable future. Due to the recognition of Lake Simcoe’s water quality problems, the LSPP requires low impact development, phosphorus offsetting from most new development and better stormwater management. However, combined with the other factors stressing the lake, we have no assurance that these improvements will be enough to bring phosphorus levels down and improve water quality.

Lake Simcoe is the most extensively studied lake in Canada. We do not need more research; we need to use the adaptive management and precautionary principles that guide the Lake Simcoe Protection Plan. Governments must protect the forests and wetlands that improve water quality, and embrace the benefits of sustainable land use planning and techniques. The science-based Lake Simcoe Protection Plan shows us how we ought to build and operate in order to protect water quality and the watershed’s ecosystem. Nothing less will do and the recommendations contained herein are designed to help fulfill this imperative.



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