Melbourne Water Corporation is responsible for the supply of drinking water to the greater Melbourne area and harvests water from approximately 160,000 hectares of public lands catchment. Melbourne Water also manages over 8,400km of waterway reserves, including creeks, streams and rivers within the greater metropolitan area. These waterways and associated reserves have extensive shared boundaries with urban and built-up areas, often with a mix of adjoining tenures and responsibilities for land and vegetation management.
The assessment and mitigation of risk to Melbourne Water’s assets and neighbours from the potential impacts from bushfires is an important part of Melbourne Water’s obligations and responsibilities. A key factor in determining the level of bushfire threat is the assessment of fuel hazard levels and the vulnerability of MW assets and neighbouring properties.
A number of methods have been proposed and used to determine the extent of bushfire protection works required on the bushland-urban interface. This typically involves requirements for fuel modification, vegetation clearing and establishment of asset protection zones. These works are often costly and with limited budgets it is often necessary to objectively prioritise the mitigation activities.
In this project we have identified an approach that stratifies bushland-urban interface vegetation into discrete areas of relative bushfire risk. LiDAR (Light Detection and Ranging) data was used to determine differences in geophysical features such as slope and aspect, as well as vegetation and fuel characteristics (such as canopy height and density) to highlight the areas of high, moderate and low bushfire risks across tenures. The approach is simple, repeatable, and LiDAR data driven, thus giving higher reliability and the decisions on treatment priorities made defensible. The methodology will be extended as a desktop exercise across the Melbourne Water waterways network and adjoining lands to systematically prioritise budget expenditures on bushfire risk mitigation programs.