How Well is the Lake Simcoe Watershed Protected?

Executive Summary

In 2019 the Rescue Lake Simcoe Coalition (RLSC) worked with cartographers from the University of Guelph to analyze the strength of the provincial and municipal environmental policies applied to the Lake Simcoe watershed landscape.

The policies were categorized into three groups based on how strongly they inhibit land use changes:

  • Best Policy Protection
  • Moderate Policy Protection
  • Not Protected by Environmental Policy

These categories were tagged to the various natural features to which they apply, and the results mapped.

Continue reading for the map and categories, which are featured in the Results and Discussion section, or use the link in the box to the right to jump ahead.

Methods and policy analysis are available here.


Results and Discussion

Jump ahead to see the results map.

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Key Targets and Research Findings

The RLSC’s 2019 “Protect Our Plan” campaign highlights two Lake Simcoe Protection Plan (LSPP) targets in its priorities for the statutory review of the LSPP:

1. Bringing down phosphorus loads to the lake and;

2. Protecting natural cover.

Target 1: The LSPP policies and its associated Phosphorus Reduction Strategy aim to bring phosphorus loads down from approximately 85 tonnes per year, to 44 tonnes per year by 2045.

What We Found

  • Despite approximately $50 million invested in Lake Simcoe from provincial and federal sources from 2007 – 2018, and the LSPP, average phosphorus loads have remained stable over the past 15 years studied;
  • There is a relationship between high levels of forest and wetland cover and good water quality;
  • There is a relationship between high water flow volumes (resulting from high levels of precipitation) and high phosphorus loads ; increasing natural cover and using more green infrastructure would mitigate the impact of high flows and reduce phosphorus going into the lake, and would increase the watershed’s resilience to climate change.

Target 2. Achieve a minimum 40 percent high quality natural vegetative cover in the watershed.

What We Found

  • The map shows us that 62% of the watershed’s land is subject to natural heritage policies that generally limit land use changes. That is a great start. But the protections are not permanent, they are applied inconsistently across the watershed, and the perpetuation of the strongest policies is at the whim of the provincial government;
  • There is a need to better protect more of the natural cover we have today in order to achieve the targets of the LSPP;
  • Land Trusts play an important role in delivering permanent protection to significant natural features, and should be supported in their efforts aimed at achieving the targets of the LSPP;
  • Only 28 percent of the watershed consists of patches large enough (25 hectares plus) to constitute “high quality natural vegetative cover”, which is comprised of woodlands, wetlands, and other rare vegetative communities like alvars and prairie grasslands;
  • The same analysis identified that only half of the watershed’s “high quality natural cover” is subject to the Best Policy Protection by strong provincial policies such as those protecting Areas of Natural Scientific Interest or Provincially Significant Wetlands;
  • 21 percent of the Lake Simcoe watershed is protected by strong policies that protect natural features of high ecological value today, but there are exceptions to protection, for aggregate and infrastructure for instance; we should not assume they will be completely or permanently protected;
  • 41 percent of the Lake Simcoe watershed currently has policies that protect natural features of lower ecological value (or have not been evaluated and determined to be more significant). The policies applied to these features are weak and often overturned.
  • The Ministry of Natural Resources and Forestry released “Technical Definitions and Criteria for Identifying Key Natural Heritage Features and Key Hydrologic Features for the Lake Simcoe Protection Plan” in 2015, which should inform municipal identification and protection of natural features. The fact that this document is no longer available online is a serious problem for transparency, and for achieving the full implementation of the natural heritage policies of the LSPP.

Note that the percentages above do not add up to 100% because there is overlap between the categories. Ie. Significant woodlands are included in high quality natural vegetative cover and under our category, Best Policy Protection.


The LSPP lacks adequate enforceable policies to ensure the achievement of the two important science-based targets above. They will not be achieved without strong policies, investments, and a measurable implementation plan. That is what the RLSC hopes to see remedied in the 2019 review of the LSPP.

The Lake Simcoe watershed could be a model for sustainable development. Simply accepting that phosphorus loadings from development will occur and “should” be offset is not a sustainable approach without demonstrating that such offsetting is actually working.

The review of the LSPP gives us an opportunity to adopt and implement future-proof policies, policies that protect what matters for the long term, while simultaneously supporting sustainable tourism, healthy lifestyles and addressing climate change impacts and high real estate values. Ultimately, permanently protecting our natural heritage will pay off.

Ontario must commit to doing this now before it’s too late.



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