Rapid adaptation is necessary to maintain, let alone expand, access to reliable, safe drinking water in the face of climate change. Existing research focuses largely on the role, priorities, and incentives of local managers to pursue adaptation strategies while mostly neglecting the role of the broader public, despite the strong public support required to fund and implement many climate adaptation plans. In this paper, we interrogate the relationship between personal experiences of household water supply impacts from extreme weather events and hazard exposure with individual concern about future supply reliability among a statewide representative sample of California households. We find that more than one-third of Californians report experiencing impacts of climate change on their household water supplies and show that these reported impacts differently influence residents’ concern about future water supply reliability, depending on the type of event experienced. In contrast, residents’ concern about future water supplies is not significantly associated with hazard exposure. These findings emphasize the importance of local managers’ attending to not only how climate change is projected to affect their water resources, but how, and whether, residents perceive these risks. The critical role of personal experience in increasing concern highlights that post-extreme events with water supply impacts may offer a critical window to advance solutions. Managers should not assume, however, that all extreme events will promote concern in the same way or to the same degree.