Intermittent rivers and ephemeral streams support diverse primary producers, including algae, that sustain trophic networks in these challenging environmental conditions. Algae adapt their morphology, physiology, and life cycle by producing mucilage or resting stages to cope with hydric stress and fluctuating water temperatures. Remnant pool-like areas that persist longer during low flow events may serve as a refuge to fuel remnant pool food webs or act as a recolonization source when flows return. The overall project uses an experimental approach to investigate the dynamics of benthic algal assemblages in pools under intermittent wet and dry conditions. I hypothesize that the transitional periods between flowing and drying phases will create environmental stressors that favor epilithic assemblages dominated by cyanobacteria or diatoms that can produce mucilage or spores during dry periods compared to diatoms adapted to thrive during flowing phases. Alternatively, lower water levels that concentrate nutrients during transitional phases could favor taxa tolerant of higher nutrient levels or, depending on the nutrient ratios, functional groups like nitrogen fixers. Epilithic algae from rocks placed in cages in pool areas of Barton Creek that experienced intermittent flows were collected at the beginning of the wet period and during the dry period. Samples will be examined for algal biomass (Chl-a & AFDW) and assemblage structure. An image-rich algal flora will be used to characterize the functional groups of algae. Samples run on a FlowCam5000 will be sorted into relative abundance of major groups (cyanobacteria, reds, greens, diatoms) and functional groups. Studied pools had no visible algal blooms, indicating that algal growth may depend more on microalgae-like diatoms during wet periods. In prolonged dry conditions, algal assemblages appeared to shift to surface, filamentous green algae, and benthic cyanobacterial mats. Results will enhance our understanding of how intermittent hydrology influences algal functional groups within ephemeral waters.