Abstract: Internet of things (IoT) in smart cities has gradually reformed the way we design urban landscapes. This research aims to introduce online monitoring systems for small-scale green stormwater infrastructure (GSI) and provides preliminary monitoring guidelines for landscape architects. It first discusses the monitoring goals, indicators, and sensors of an intelligent GSI system. Formulations and monitoring approaches of the inflow/outflow based on water balance are also proposed. To provide explicit instructions, it demonstrates three monitoring prototypes for different scenarios of GSI: open/closed watersheds, permeable/impermeable conditions, and stable/unstable water bodies. This research further introduces an available pattern of data transmission and concludes that online monitoring systems conduct inconspicuous space interventions to achieve a superposition of the virtual domain and the physical space.