In 2008, pastoral communities who had settled in Usangu Wetlands of Southern Tanzania for since the 1950s were evicted by government due to the need to conserve the wetlands as part of the catchment area for the Great Ruaha River, which started drying up during the dry season in 1993. Since there was no trade off debate between government and the pastoralists before eviction, the major aim of this paper is to analyze this decision using the trade-off approach in particular an heuristic approach. To achieve this, the paper first describes the scenario, identifies issues on decision making, and uses the trade-off decision approach to analyze the government decision to evict the pastoral communities. The analysis uses an heuristic approach, which identifies: need for effective comparative analysis of values as perceived by pastoralists and government; unintended consequences of unfulfilled promises, which may reverse any values on both sides; level of government most appropriate for implementing such decisions at community level; and how the translation of authority between national and local level government is undertaken to minimize negative tendencies, showing that trade-off approach is multidimensional. The paper illustrates and re-emphasizes the use of an heuristic approach at different levels of decision making concerning conservation and development as a better way to examine and arrive at acceptable positions in an equally demanding but contrasting alternatives.