Study region: The 48,010 km2 study area in the Brazilian semiarid includes three major watersheds and 26 strategic reservoirs supplying water for multipurpose uses. Study focus: In this research, we evaluated water release in drylands with a participatory allocation system that has been consolidated for more than twenty years. Historical data (2004-2022) on storage and release from 26 reservoirs were analysed using concordance measures at the daily, monthly, and seasonal scales, along with records from river basin committee meetings. Clustering of hydrological, demand, and correlation data was performed. Furthermore, a Driver-PressureState-Impact-Response (DPSIR) framework was used to systematise qualitative and quantitative aspects of water allocation. New hydrological insights for the region: At the daily scale, rapid releases and interruptions weakened the monotonic association between storage and release, which became moderate at monthly and seasonal scales. The results suggest potential limitations in using volume-driven decision tables to predict water release from these reservoirs. In the most severe drought conditions, water users expanded the debate on adaptive water management. Hydrological and demand clustering aligned, differing from correlation-based clustering. In DPSIR, responses to quantitative questions, such as water release interruptions, were reported more frequently than responses to qualitative ones, such as pollution containment barriers. Our research enhances the understanding of water systems with strong social participation and supports modelling and management scenarios, especially in drylands.