A case study approach based on examples from the Black Hills region is used to evaluate the role of water professionals in developing feasible and fair public policy involving water resources. Examples presented include a long-term hydrologic investigation in the Black Hills, a local wellhead protection program, issues being addressed by a local flood management commission, coordination of definitions of beneficial stream uses by two state agencies, water-quality problems related to rapid population increase in a rural area, and impacts of potential climate change on water resources. In some of these examples, the hydrologic work was separated from policy making to ensure neutrality. In other examples, involvement of the hydrologists and water resource engineers directly benefited policy development. Opportunities for increased effectiveness were observed in most of the examples.