OFA provides comments on the Lake Simcoe Protection Plan 10-year Review. OFA believes Plan updates are not needed at this time but continued success will require continued investment and support. Given the many successes and improvements described along with the adaptability of the Plan, OFA believes the Plan continues to work as intended. OFA recommends continued investment by government to incentivize the voluntary implementation of Best Management Practices and government financial and technical support for research projects. OFA supports the Plan’s continued involvement with respect to urban and non-farm sources of phosphorus into Lake Simcoe as well. Given the increasing urbanization of the watershed, it will remain essential to ensure phosphorus from these sources is not increasing. The review report identifies addressing invasive species as a priority of the Plan. However, research appears to still be lacking regarding these invasive species’ impact on phosphorus levels in the Lake. OFA believes that significant factors relating to the state of the Lake were not considered in early studies that that resulted in calculating phosphorus contributions to Lake Simcoe, specifically legacy phosphorus, and the role of invasive species. For example, the studies did not attribute any phosphorus in the Lake to the impact of wave action on stirring up phosphorus in the sediment of the Lake. OFA recommended that studies should begin to look at issues of legacy phosphorus in the Lake sediment, how it is mobilized and attempt to quantify this phosphorus source.