Aquifer-Stream Interactions (ASIs) play a critical role in effective groundwater management, yet their complex dynamics remain poorly understood in channelized lowland perennial streams. This study presents a multi-scale, multi-technique investigation of ASIs along two streams in Shelby County, Tennessee, overlying the confined Memphis aquifer. The goal is to define a suitable methodology for characterizing ASIs in this specific hydrological setting, serving as a starting point for developing a standardized approach. The methodology includes an initial evaluation of various field techniques, followed by extensive surveys using potentiomanometers, electromagnetic induction (EMI), vertical temperature profilers (VTPs), and complementary techniques such as seepage meters, bank tests, and well-data analyses. Results reveal distinct hydrogeomorphic behaviors across and along the streams, challenging the ASI homogeneity notions typically assumed in groundwater models. Nonconnah Creek exhibited streambed colmation and negligible hydraulic gradients, resulting in disconnection from the aquifer during low flows, except for a 300-m losing reach with high downward gradients, potentially degrading the Memphis aquifer. In contrast, the Loosahatchie River displays relatively homogeneous streambed properties and small, upward hydraulic gradients, suggesting uniform ASIs along the surveyed reaches. EMI proved highly effective for mapping streambed sediments quickly, while potentiomanometers accurately measure small head differences critical for understanding ASI dynamics. VTPs were less practical due to extended data-collection times and vulnerability to flooding. This study emphasizes the importance of site-specific, multi-scale investigations using diverse techniques to accurately characterize ASIs in lowland streams, highlighting the confounding influences of geological formations, anthropogenic alterations, and depositional processes on groundwater-surface water interactions. The findings contribute to refining local water balances, informing groundwater management strategies, and underscoring the need for incorporating local-scale field data into regional groundwater models. The proposed methodology serves as a foundation for developing a standardized approach for characterizing ASIs in lowland channelized perennial streams, adaptable for similar stream systems worldwide.