In a context of increasing housing demand, many greenfield areas at the outskirts of major cities are gradually being turned into urban areas. Green infrastructure systems and/or Water Sensitive Urban Design (WSUD) are alternatives to conventional drainage systems that aim to capture, manage and treat urban runoff to maintain a good ecological health of receiving water bodies. This long-term experimental study, i.e. 10-15 years, aims to track through time, the changes occurring as one catchment (Tiireke) changes from rural to urban land use, integrating WSUD, compared to a conventional (i.e. “Business as usual” (BAU), no WSUD) catchment (Rukuhia). Initial results suggest that early stages of development and earthworks have already resulted slightly higher suspended solids (SS) and copper exports compared to upstream rural undeveloped areas. SS export was however much higher from the nearby conventional urban catchment. Although it is expected that the Rukuhia BAU subcatchment contributes to copper export, this was concealed by in-stream attenuation of the high input loads from its upstream rural/peatland subcatchment. An alternative BAU catchment, with no upstream contaminant export influence, is being investigated for the next phase of monitoring. Initial data analysis of the broad list of monitored pollutants and planned activities in the Tiireke catchment will help refine the monitoring strategy for future years to better capture the impact of development activities and the benefits provided by the widespread use of WSUD once developed, when compared to a conventional urban catchment.