Hydropower dams regulate water flows for millions of downstream inhabitants worldwide, altering water availability. Under a changing climate, flow control is often framed technically and politically as being essential for reducing drought and flood risks. However, it can also disrupt ecological flows, impact livelihoods and erode environmental knowledge. We contribute to this debate by examining how ribereños —rural communities in Colombia characterized by their interdependence with rivers—experience fluctuating water levels. We focus on ‘dry events’, situations where decreases in the river's water levels hinder ribereños' livelihoods. Our case study, the Lower Sogamoso River (dammed in 2014 by Hidrosogamoso Dam), no longer follows a clear pattern of rising and falling waters, which previously allowed ribereños to prepare socially and economically for seasonal activities. Drawing on a relational perspective on rivers and infrastructures, we mobilize the notion of rhythms to account for the temporal dimensions of hydrosocial relations and sociotechnical infrastructures. Using an interdisciplinary combination of ethnographic research and statistical analysis of hydrological and electricity data, three distinct situations come into view: the regular dry season, hourly low water levels and the 2015–2016 El Niño. Our findings demonstrate how temporal operations of hydropower and associated pricing mechanisms transform the hydrosocial relations of riverine communities. Daily operations disrupt gradual seasonal streamflow patterns, hindering seasonal livelihoods, while pricing decisions generate disruptive events on an hourly scale. During the 2015–2016 drought, the energy company's water storage and price bidding strategy led to unprecedented water level variations. Synthesis and applications . Our interdisciplinary approach made it possible to connect the temporal experiences of communities with large electricity market fluctuations. We emphasize that dry events must be assessed not only based on climatic conditions or dam presence but also taking into account the intersection of temporal logics at multiple scales. We underscore the need to evaluate streamflow variations at both daily and hourly scales, which are often overlooked in research and policy yet are essential for riverine cultures across the globe. Read the free Plain Language Summary for this article on the Journal blog. Spanish translation: Read the free Plain Language Summary for this article on the Journal blog.
Betancur‐Alarcón et al. (Thu,) studied this question.