The importance of riparian vegetation for aquatic habitat is well established in the ecological conservation literature, but urban planning agencies' limited understanding of landowners' motivations for, and interest in, riparian conservation has left them unable to prevent its loss along stream corridors. For this study I surveyed streamside residents in the Puget Sound Lowland to examine their perceptions of and preferences for riparian vegetation. I found that property owners' preferences do not match conditions on their own land, and my results suggested several possible causes, including: poor information about how to limit ecological degradation and what actions are permissible along streams; fears about potentially negative impacts of making changes; and cost, time, and other constraints that prevent owners from making changes.