The University of Washington's Climate Impacts Group (CIG) performs integrated assessment of climate impacts on the hydrology and water resources of the Pacific Northwest, with the goal of increasing regional resilience to changes or variations in climate. This work requires integrating physical and social science approaches to appropriately contextualize understanding of the physical system within the institutions that influence it. This talk will draw on several examples from CIG's research in the Columbia River basin (concerning the development of hydroclimatological forecast applications and an assessment of the basin's vulnerability to climate variability and change) to illustrate a methodology for addressing issues relevant to regional water resources management and decision-making. This approach is anchored by an understanding of the physical (hydroclimatological) system and requires both an assessment of the effect of human activities on the physical system and an evaluation of the institutional context, that is, the "rules of the game" that guide social practices relevant to the system under examination. Specific research approaches useful for evaluating the institutional context include mapping institutional frameworks, interviewing stakeholders, and elicitation of decision calendars. The proposed approach is most successful when research on the three components is undertaken in parallel, rather than in series, thus encouraging cross-fertilization and enabling mid-course consistency checks and adjustments.