Index of Estuarine Condition Estuarine Flow Barriers

IEC2021_BARRIERS indicates locations of estuarine barriers (partial and complete) that were used in the 2021 Index of Estuarine Condition. A combination of existing data sources and field data collection was used to identify the existence of artificial barriers and whether these structures represented partial or complete barriers (Pope et al. 2015). Partial barriers were those that were considered to allow limited or intermittent movement of biota. Complete barriers were those that represented an absolute and permanent barrier to biota. Where artificial barriers were identified, the most likely location of the natural (pre-1750) inland extent (length) of the estuary was derived from historical documents, field observations, elevation data and geomorphology to provide a `natural estuary length¿.