Small hydropower facilities in Brazil affect downstream flow regimes by releasing water at variable rates, causing hydropeaking. This study analyzed 11 river reaches with 24 hydropower facilities in the Pantanal wetland area. Results show that hydropeaking leads to significant sub-daily changes in flow patterns, with indicators like rate of rise and fall, amplitude, and duration of high pulses being most affected. These alterations occur in all months and are not related to river or facility characteristics. Both small and large hydropower facilities contribute to hydrological changes through hydropeaking, highlighting the need to understand the ecological impacts in tropical river systems.