This report evaluates the costs and benefits of floodplain protection in Waterbury, Vermont and Willsboro, New York in the Lake Champlain Basin, U.S.A. The primary elements of the project are ecosystem services valuation, buildout/conservation analysis, hydrologic calculations of current existing peak flows and predicted future peak flows, hydraulic modeling of floodplains, building damage simulations due to flooding, and cost-benefit accounting to determine the best form of flood risk reduction for each community. The most economically sound flood risk mitigation plans were found in towns in which damage reductions were high, the loss of tax revenue was low, the cost of mitigation activity was low, and the ecosystem service value was high.