A collection of Integrated High Ecological Value assets that form the natural hydrological grid across 34 Local Government Areas within the Greater Sydney Region. This data has been prepared by the Science Division of DPIE (former OEH), with input layers and support for the map provided by the NSW Department of Primary Industries-Fisheries and Department of Industry-Crown Lands and Water. Similar mapping has been prepared by OEH for the Land Use and Infrastructure Implementation Plans for the Wilton (Wilton2040, page 22) and Greater Macarthur (interim plan, page 36) Priority Growth Areas. These data packages were specifically developed for input to Local Government Local Strategic Planning Statements to support Council’s delivery of Strategy 25.1 of the Greater Sydney Region Plan.

The map shows areas where waterways and water dependent ecosystems are defined as high ecological value, based on definitions, guidelines and policies under the Environment Protection and Biodiversity Conservation Act 1999, Biodiversity Conservation Act 2016, Fisheries Management Act 1994 and Water Management Act 2000. Water dependent ecosystems are defined as wetlands, and flora and fauna that rely on water sources (including groundwater). The map represents an overlay of 39 indicators being used by the State Government to define high value water dependent assets. The method used to derive the integrated layer is similar to mapping produced for the draft Cumberland Plain Conservation Plan.

The purpose of the map is to identify strategic planning priorities for protecting and improving the health of high value waterways and water dependent ecosystems in the Greater Sydney Region LGAs. Once identified, the priorities can be used as a basis for identifying aquatic biodiversity refugia, stream rehabilitation efforts and setting management targets and/or land use planning controls that would protect or improve the health of waterways and water dependent ecosystems so they provide the essential services and functions expected of a cool blue-green corridor.

The datasets were created by initially placing a 1-hectare hexagon grid over the relevant boundary area and attributing the grid with either ‘Absent’ or ‘Present’. This represents an occurrence only of high value water dependent ecosystems layers within the hexagon grid. The ‘HEVlyr’ field provides a count of the number of layers within the hexagon. A value of zero (0) represents Absent, values of greater and equal to one (1) represents the Presence of high ecological value assets. The values DONOT indicate the significance of the area, i.e., a value of 1 is no less significant to a higher value. Where layers are Present, please contact data steward for details relating to the underpinning datasets.