The study of watershed storage is critical for understanding watershed hydrologic functions, ecosystem dynamics, and biogeochemical processes. However, few studies have quantified how much water lies in the subsurface in urban watersheds. In this study, dynamic storage was estimated, and storage-discharge relations evaluated in Atlanta, GA among variably urbanized watersheds. Streamflow data from 2012-2016 was utilized and the simple dynamical systems model employed. Dynamic storage values in these watersheds are small: ~3mm to ~9mm. The small dynamic storage values observed across the watersheds are linked to watershed urbanization; however, other subsurface properties of the watersheds may also account for this small storage values. Storage-discharge relations across all the watersheds are non-linear, except the most developed sub-watershed (35% impervious surface area). Two less urbanized sub-watersheds (21% and 26% impervious surface area), showed high streamflow sensitivity. Overall, this study shows that the simple dynamical system model performs well in urbanized watersheds and the South River Watershed can be regarded as a dynamical system.