An infilled backbarrier wetland located behind a stationary-type coastal bay barrier is used to reconstruct a 6000-year paleo-environmental record that incorporates gradual, catastrophic, and human-influenced sedimentation styles on the New Zealand coast. The record is assembled from a range of proxy indicators (grain size, magnetic susceptibility, organic content, diatoms, and pollen) and is temporally constrained by tephrochronology, radiocarbon dating, and optical dating. Postglacial sea-level rise, volcanism, tsunami, and catchment clearance are all evident in the sediment record, either as artifacts or indirect indicators. Results from optical dating also provide insights into the process of sediment reworking and mixing from multiple sources during tsunami transport. We argue that backbarrier wetlands formed behind stationary-type (aggraded) bay barriers are of greater value (more sensitive) for longer-term paleo-environmental reconstruction than wetlands associated with prograded-type and receded-type barriers, where the sediment record is typically less complete.