A democratic premise is that expert influence should not extend into the political domain of environmental policymaking. This article analyses the relationship between experts and policymakers in the historical development of the National Flood Insurance Program as a flood governance strategy in the United States. The article draws three conclusions. First, while experts asserted great influence on the development of this policy program, underlying values were evaluated and judged by policymakers. Second, as socio-political values changed, new types of experts were (...) involved in the policymaking process. Third, these different types of experts had different implications for how value conflicts were addressed. (shrink)