Filamentous algae (FA) and rooted aquatic plants (macrophytes) are essential primary producers in rivers, providing habitat and basal food resources. However, excessive biomass accumulation can negatively impact the ecosystem and the people that utilize it. The Klamath River in Southern Oregon and Northern California has high rates of primary production, and excess growth in the summer can lead to clogged infrastructure, reduced dissolved oxygen, and impaired beneficial and cultural uses. The world’s largest dam removal on the Klamath River in 2024 provided an opportunity to investigate conditions influencing FA and macrophyte growth, including the impacts of a large sediment pulse and spring peak flow variability. We hypothesized that increased turbidity from sediment pulses associated with reservoir evacuation would inhibit growth by reducing benthic light. With this study we aim to: (1) document biomass and growth timing of FA and macrophytes compared to pre-dam-removal light availability and discharge conditions, and (2) identify environmental mechanisms limiting and driving growth. We collected field data before and during dam removal and applied a mechanistic model and random forest analysis to examine limiting growth factors. We collected bi-weekly FA and macrophyte biomass, %cover, and physical habitat characteristics (velocity, temperature, depth, light availability, turbidity) at two sites downstream of the dams during summer 2023 (pre-removal) and 2024 (during removal). The sediment pulse from dam removal did not appear to delay FA and macrophyte growth, and conditions permitted persistent growth despite consistently high turbidity, potentially due to the lack of high spring pulse flows. However, we cannot compare results to a clear-water, pre-dam removal scenario due to high turbidity from 2023 wildfire sediment pulses. We expect model results to reveal similarly low sensitivity to light availability compared to flushing flow and scouring mechanisms. We are exploring these mechanisms across different scenarios using these models to inform how management actions may impact biomass accumulation in the Klamath River.