Areas of estuarine waters derived and updated by the Index of Estuary Condition funded by the Department Environment, Land, Water and Planning. Underlying estuarine areas were produced by  Deakin University as part of the projects: "Linking catchments to the sea: Understanding how human activities impact on Victorian estuaries" funded by the National Heritage Trust (Barton et al., 2008) and the Department of Sustainability and Environment and the Trial Implementation of the Index of Estuary Condition, funded by the Department of Sustainability and Environment and Deakin University (Pope et al., 2015).

Areas of estuarine waters derived and updated by the Index of Estuary Condition funded by the Department Environment, Land, Water and Planning. Underlying estuarine areas were produced by  Deakin University as part of the projects: "Linking catchments to the sea: Understanding how human activities impact on Victorian estuaries" funded by the National Heritage Trust (Barton et al., 2008) and the Department of Sustainability and Environment and the Trial Implementation of the Index of Estuary Condition, funded by the Department of Sustainability and Environment and Deakin University (Pope et al., 2015).

ESTUARIES is a spatial representation of estuarine water areas.  It was prepared by the Arthur Rylah Institute (DELWP) for the 2021 Index of Estuarine Condition. It was built on the work by Deakin University's assessment of catchment-based threats to estuary health.  Work by Deakin University includes modifications to an earlier layer with data from a project extension that aimed to improve the spatial accuracy of upstream boundaries for selected estuaries.  

Details of selection of estuaries and spatial definition of mouths and heads are provided in Barton, J.L., Pope, A.J., Quinn, G.P. and Sherwood, J.E. (2008) Identifying threats to the ecological condition of Victorian estuaries (Department of Sustainability and Environment Technical Report, ISBN 978-1-74208-745-0 (online)).  Additional survey work to identify locations of upstream limits resulted in modifications to 25 estuaries, upstream limits of 22 additional arms of those 25 estuaries and the exclusion of 2 previously included estuaries (Wild Dog and Anderson) on the basis of the length criteria identified in Barton et al. (2008).

Spatial identification of estuarine areas will be critical to inclusion of estuaries in the river management framework that includes the expansion of fluvial condition and risk assessment methodologies to estuaries. The aim of this layer is to eventually map current estuarine extent of Victoria's estuaries to a 1:25000 or better scale.

Polygons are derived from multiple sources:
-Vicmap water areas and watercourses (1:25,000)
-Upstream limits digitised by Deakin University based on methods described in Barton et al. (2008) and Popet al. (2015)
-Mouth widths and locations based on 1:25,000 topography and those described in Barton et al. (2008) and Pope et al. (2015).

Coast types were derived from Barton et al. (2008).

Mouth type was derived from Oil Spill Response Atlas 2001 v_rivers layer - see relevant metadata. Mouth type was reviewed and updated as part of Pope et al. (2015)

Head position as described in Barton et al. (2008) then updated following survey of the following systems (including relevant tributaries): Port Campbell Ck, Sherbrook River, Barham River, Kennett River, Wye River, St George River, Spring Ck, Swan Bay, Hovells Ck, Laverton Ck, Yarra River, Balcombe Ck, Merricks Ck, Cardinia Ck, Deep Ck, Bunyip River, Yallock Ck, Yallock outfall, Lang Lang River, Bass River, Wingan Inlet, Easby Ck, Shipwreck Ck, Davis Ck and Mallacoota Inlet.

Head position of all estuaries reviewed and surveyed as described in Pope et al. (2015)

Dataset Source: Original polygons are derived from Vicmap Hydro watercourses and water areas parcels with additional seaward boundaries derived from the vcst25g_a coastline database, Details of upstream and downstream boundaries in Barton et al. (2008) with additional survey work identifying upstream limits of some estuaries to 1:25000 or better. Further updates were made using high resolution aerial imagery for the 2021 Index of Estuarine Condition (Department Environment, Land, Water and Planning).

Refer to metadata for Vicmap Hydro watercourses and water areas and vcoast25g_a. See Barton et al. (2008), Pope et al. (2015) and DELWP (2021) for sources of text attributes.

Barton, J., Pope, A., Quinn, G. and Sherwood, J. (2008). Identifying threats to the ecological condition of Victorian estuaries. Deakin University, School of Life and Environmental Sciences, Warrnambool. 92.

Pope, A., J. Barton, and G. P. Quinn. (2015). Victorian Index of Estuary Condition: Implementation Trial Final Report. Warrnambool, Victoria.

DELWP (2021). Assessment of Victoria¿s estuaries using the Index of Estuary Condition: Results 2021. The State of Victoria, Department of Environment, Land, Water and Planning, East Melbourne, Victoria.


Dataset Originality: Primary & Derived

                            
                              Relationship to other Datasets: This layer is compatable with the IEC layers and links via the EUID

Current Design Issues: Lateral boundaries of some estuaries are based on areas defined by 1:25,000 Vicmap water areas or, where Vicmap watercourses exist, by a 5 metre buffer of those line features.  No assessment of the current accuracy of these lateral boundaries has been made, nor is a particular channel width implied in the buffered sections.

Upstream limits of some estuary channels are still based on derived locations and estimates.  Such limits (identified by the head_posit attribute) are indicative only.

Future Design Issues: Improve estimates of upstream limits of estuaries to 1:25,000, especially W Gippsland.

Changed locations of estuary heads will allow fluvial and estuarine catchment areas to be revised to reflect new boundary positions.

Related Documents: None

Refer to metadata for Vicmap water area and watercourses and Barton et al. (2008) and Pope et al. (2015).