Multi-Objective Modeling to Improve Wetland Diversity around Lake Ontario

Since 1960, the outflows of Lake Ontario have been controlled and water levels managed by the structures within the St. Lawrence Seaway and Hydropower Project. These operations have enabled the generation of hydroelectric power, commercial navigation from the Atlantic Ocean to the Great Lakes and benefits through a reduction of flooding of properties along the lake's shoreline. However, the resulting reduced range of levels negatively affected the lake's wetland diversity compared to that which existed pre-project. The recently completed International Lake Ontario-St. Lawrence River Study proposed alternative operational plans which improve conditions for all interests and increase ecological benefits, principally wetland diversity; creating no disproportionate loss to any interest. The Study used a Shared Vision Planning approach along with an Integrated Ecological Response Model to investigate alternative management plans and determine their impact in terms of environmental performance indicators. This paper describes the estimated impact that current lake level management has had on wetlands and selected biota and the alternative plans developed by the Study Board to improve conditions. It also describes the adaptive management procedures proposed to assure that the anticipated results would be fulfilled.