Managing a Lake That Flows Both Ways

Vancouver Lake, an urban eutrophic lake in Vancouver, WA, is considered a regional “gem” but, despite decades of research and restoration efforts, the lake and its users continue to suffer from a variety of issues including annual toxic HABs and noxious aquatic weeds. Championed by the local Friends of Vancouver Lake group, the state legislature has awarded Clark County funds to restore Vancouver Lake through the development and implementation of a management plan. Development of the 2023 Vancouver Lake Management Plan (VLMP) included engaging technical experts and local stakeholders, and evaluating feasible management alternatives using lake modeling and cost-effectiveness analyses. One of the key recommendations of the VLMP, based on the results of these analyses, called for enhanced lake flushing to reduce toxic HABs. Today, the project team, technical experts, and local stakeholders are working to 1) develop a funding and governance structure to ensure sustainable, long-term lake management; 2) evaluate the efficacy of piloted near-term beach management solutions to minimize risks to public health; 3) design flushing enhancement options; and 4) update and refine the linked hydrodynamic (HEC-RAS 2D) and water quality (WASP) model to further inform the feasibility of flushing options and advance implementation of long-term solutions. We encountered a number of social and scientific challenges throughout this project. In this presentation, we will summarize project goals and progress to date, and describe the successes and lessons we’ve (l)earned along the way. Through innovative problem-solving and collaboration, we’re excited to move forward together to restore Vancouver Lake.