Ecological and geomorphic theory assume longitudinal connectivity; here, we test whether these concepts apply in naturally disconnected paraglacial stream networks with lakes and coarse glacial sediment. We determined downstream hydraulic geometry relationships (DHG) for channel width; riparian vegetation was inventoried across process domains (rapids, flats, lakes) over 10 km in two northern Swedish catchments—one above and one below the former highest coastline (FHC). Below the FHC, finer sediment from marine/deltaic deposition may allow more stream self-adjustment. DHG relationships were weak overall, with large local width variation, but slightly stronger in the FHC-below catchment, where a lake-effect was found, with wider channels downstream of lakes. Riparian vegetation species density did not substantially increase downstream as in connected stream networks, and vegetation similarity between reaches was weakly related to distance, suggesting disrupted dispersal. These findings indicate that formerly glaciated catchments are highly fragmented, with local factors dominating geomorphic and ecological patterns.