“…These coupled but functionally different porosity domains result in a spectrum of solute residence times in the hyporheic zone that may show power‐law distribution in channel return flow (Aubeneau, Hanrahan, Bolster, & Tank, ; Cardenas, ; Cardenas, Cook, Jiang, & Traykovski, ; Gooseff, McKnight, Runkel, & Vaughn, ; Haggerty, Wondzell, & Johnson, ). Residence time of water and solute directly impacts contaminant transport, microbial reactions, aquifer management, and the implementation of remediation techniques (Briggs et al, ; Cardenas, ; Culkin, Singha, & Day‐Lewis, ). Simplified stream‐based solute transport models that assume homogeneity for the hyporheic zone cannot capture the complex exchange between mobile and less‐mobile domains, which can have a substantial effect on the solute transport and reactive processes (Day‐Lewis & Singha, ; Gao et al, ; Singha, Day‐Lewis, & Lane, ).…”