Geomorphology and American dams: The scientific, social, and economic context

American geomorphologic research related to dams is embedded in a complicated context of science, policy, economics, and culture. Research into the downstream effects of large dams has progressed to the point of theory-building, but generalization and theory-building are from this research because (1) it is highly focused on a few locations, (2) it concerns mostly very large dams rather than a representative sample of sizes, (3) the available record of effects is too short to inform us on long-term changes, (4) the reversibility of changes imposed by dam installation and operation is unknown, and (5) coordinated funding for the needed research is scarce. In the scientific context, present research is embedded in a history of geomorphology in government service, with indistinct boundaries between “basic and applied” research. The federal policy that most strongly influences present geomorphological investigations connected with dams is related to habitat for endangered species, because the biological aspects of ecosystems are directly dependent on the substrate formed by the sediments and landforms that are influenced by dams. The economic context for research includes large amounts of public funds for river restoration, along with substantial private investments in dams; and geomorphology is central to these expensive issues. The cultural context for research is highly contentious and dominated by advocacy procedures that include intense scrutiny of any geomorphologic research related to dams. Advocates are likely to use the products of geomorphological research to make cases for their own positions.