Periodic cessation of stream flow results in changes to invertebrate community structure over time. Initially resistant taxa or resilient colonizers from nearby perennial streams are able to reestablish quickly when flow resumes followed by continued community recovery. Previous research has noted that taxa in non-perennial streams are often smaller-bodied with faster life cycles compared to those in perennial streams. Few studies, however, have examined how such alterations to community structure change food-web properties and energy transfer. Size-spectrum analysis examines body mass-abundance relationships to assess how they affect the efficiency of energy transfer and food-web structure. We examined how flow regimes, ranging from non-perennial to perennial, altered invertebrate size spectra across three nested reaches within multiple headwater streams in Alabama, USA. We collected riffle (n=4) and pool (n=4) samples from each reach four times from 2021 to 2022. We processed and identified samples to the lowest possible taxonomic resolution and measured lengths to quantify biomass. We collected continuous stage-data within each reach to characterize flow regime and physical stream attributes including width, substrate type, and depth, on each sampling occasion. We observed a reduction in invertebrate mean body size and abundance as flow declined within riffles but not pools. Future work will examine the shifts in functional feeding groups across sites, with the potential to examine shifts in energy transfer pathways. By examining both pool and riffle habitats in non-perennial sites relative to nearby perennial sites, we are able to compare the relative effects of flow cessation across habitats while accounting for available local diversity. Size-spectra analysis provides a more nuanced understanding of shifts in energy transfer as stream communities experience more frequent or longer periods of drying.