The variability of topography, geology, climate; vegetation, and land use in the Pacific Northwest creates considerable spatial and temporal variability of fluvial processes and reach-scale channel type. Here we identify process domains of typical Pacific Northwest watersheds and examine local physiographic and geologic controls on channel processes and response potential in the Puget Sound region. We also review the influence of different channel types on opportunities and limitations for channel restoration. Finally, we develop regime diagrams that identify typical combinations of channel characteristics associated with different alluvial channel types. These diagrams can be used to set target values for creating or maintaining desired channel types and associated habitats or to assess the stable channel morphology for imposed watershed conditions. Regime diagrams that are based on explicit physical models also can be used to predict likely trends and magnitudes of channel response to natural or anthropogenic disturbances (such as restoration activities). Moreover, spatial linkages of processes and the potential for distal disturbances to propagate through channel networks means that local restoration efforts that do not address larger scale watershed processes and disturbances may be ineffective or costly to maintain.