As water demand drastically increased due to growing population and urbanization over the last century, a vast installation of reservoirs proliferated worldwide, fundamentally changing the water cycle (Ripl, 2003). Large-scale water regulation and conveyance systems currently determine present and future water availability to society (Sivapalan et al., 2003, Vogel et al., 2015Vörösmarty & Sahagian, 2000). In the United States (U.S.) alone, more than 90,000 dams change the quantity and variability of natural flow regimes, altering an estimated >85% of inland waterways (National Research Council, 1992). The impacts of such alteration propagate through river networks and affect the fluvial ecosystem in multiple ways: by preventing sediment transport (

Dams are a major contributor to flow regime alteration: they increase water residence time, mute peak flows, shift the timing of ecologically important high and low flows, and alter flow periodicity (Poff et al., 2007;Ruhi et al., 2018;Vorosmarty, 1997). These alterations adversely affect riverine and riparian biodiversity because the life-history, morphological, and behavioral adaptations of organisms are often at odds with the novel environmental regime (Bunn & Arthington, 2002;Lytle & Poff, 2004;Mims & Olden, 2013). Such flow regime alteration is also often detrimental to society, as it may disrupt floodplain fishing, flood-recession agriculture, and a wide range of recreational and cultural values (Anderson et al., 2019). Despite intense scrutiny, flow alteration by dams has largely been estimated via methods that do not take into account the spatial context in which these changes