Dataset Number 2717 Dataset Title Flooding - Levee Banks Custodian Data Authority: Department for Environment and Water Data Provider: Department for Environment and Water

Description Description The Levee Bank dataset provides a baseline of levee bank information utilising existing topographic data sources (primarily TOPO.LeveeBanks) and a desktop assessment of field and survey information, including high resolution LiDAR and aerial photography and data feedback from a stakeholder survey. The layer includes levees and embankment features, and contains general (contextual) and levee specific information (where available) relating to identified levee features in South Australia. Usage The Levee Bank layer is intended for use across flood management and emergency response activities within State Government and Local Council. The layer provides an indication of the location of levees. It cannot be assumed that all features currently behave as levees or provide protection from flooding. Many levee features require further on ground verification to confirm whether the feature behaves as a levee or affects the movement of flood water. The layer is subject to improvement based on feedback from government and asset owners.

Data Quality Lineage Levee features have been compiled and digitised from a number of sources including from existing DEW topographic dataset TOPO.LeveeBanks, high resolution LiDAR and aerial imagery (where available) at approximately 1:5:000, and from feedback from an online spatial survey conducted during 2022. Particular areas of focus in developing the dataset include the River Murray (many features validated during the 2022/23 flood event), Lower Gawler River (through the DEW lead Gawler River Flood Management Project), City of Salisbury (line features provided to improve coverage in this council area), areas where high resolution LiDAR was acquired by Green Adelaide (Adelaide Metro) and the DTI PLUS Flood Hazard Mapping and Assessment Project (including townships of predicted growth/development) Clare, Gumeracha, Middle Beach, Mount Barker, Nuriootpa, Strathalbyn, Victor Harbor and Yankalilla, and other townships including Georgetown, Gladstone, Hawker, Jamestown, Laura, Naracoorte, Quorn, Spalding and Wilmington. Levee_Owner_Type attributes have been derived using DCDB.GovLand. Where a levee extends across more than one property with different land owner types, the main land owner type is applied. A table of levees and associated individual land owners is available for internal emergency management activities. Completeness Data is complete where recent LiDAR data is available and where TOPO.LeveeBanks and other data providers have provided line features (i.e. City of Salisbury and River Murray). This dataset does not contain all existing levees across the state, but those known and digitised through the above sources. A small number of features with Feature Code 'Embankment' have minimal attribution due to being derived from old 1:50,000 mapping data. It is likely that these features exist in the landscape but the reliability of these features is low. Land_Owner_Type, Levee_Function, Levee_Status and Levee_Type_Material fields have incomplete attributes. These fields have been populated where possible and to the best of our current understanding. Positional Accuracy Positional accuracy for 99% of features ranges from +/- 5m to +/-25m.

Geographic Extent Extent Name South Australia Min Easting or Longitude 129 Min Northing or Latitude -38.25 Max Easting or Longitude 141 Max Northing or Latitude -26

Dataset Status Initially Acquired 01/07/2023 Last Updated CURRENT Update Frequency As required Maintenance Method Updated as required via digitising from high resolution elevation models and assessment of survey plans or other quality information products including data provided by asset owners. AusGOAL Not yet determined

Attributes

Contact Information Organisation Department for Environment and Water Economic and Sustainable Development Postal Address GPO Box 1047 ADELAIDE 5001 Email DEWNR.CustomerServiceCentre@sa.gov.au