Green infrastructure refers to a range of urban stormwater management tools that can be flexibly implemented. These practices can aid in mitigating the negative impacts of runoff by increasing catchment detention capacity. We studied two engineered rain gardens (Cleveland OH) that were designed to infiltrate and detain direct runoff volume generated from an adjacent roadway, and sheet flow from pervious areas of each catchment area. We also accounted for hydrologic interactions between the engineered and upslope basic (non-engineered) rain gardens. A whole water-cycle monitoring approach was employed to fully assess the role of green infrastructure interventions on performance as inflows captured, duration of outflow drainage (i.e., excess moisture), hydrologic losses (e.g., evapotranspiration), and groundwater table dynamics. We found that these tandem rain gardens had good capacity for runoff inflow volumes over the course of over 100 storm events.The integration of green infrastructure in urban landscapes and long-term monitoring for effectiveness and its key functions produces novel data that can be used by researchers and other interested parties to conduct assessments of urban ecosystem functions and leverage these unique datasets by integrating with other datasets as per good scientific practice. We role model good monitoring practice, discuss unique ways to interpret challenging hydraulic circumstances, and conclude with a discussion of monitoring techniques that scale between the simple, passive and elegant; to full-blown research-grade monitoring infrastructure such as that employed in this study.