Field surveys and investigations

Traditional Owners, cultural heritage advisors and archaeologists conduct field surveys and investigations to identify if evidence of Aboriginal cultural heritage is present and to assess the extent, nature, and significance of any material that is identified. The findings are used to assess the potential impacts to Aboriginal cultural heritage within and surrounding the proposed route.

A standard assessment (walk over) typically involves an on-foot field survey to assess ground conditions, identify areas of archaeological potential, and inspect the area for surface evidence of Aboriginal cultural heritage. On occasion more complex surveys may be required. This entails digging a series of shallow pits and sieving soil to look for potential artefacts in targeted areas. This testing aims to establish the presence or absence of any subsurface Aboriginal cultural heritage material. If subsurface Aboriginal cultural heritage material is identified, additional subsurface testing may be required to determine the extent. At the completion of excavation and recording, all test pits will be backfilled, and the area reinstated, as per land manager or municipality requirements. 

Cultural values assessments are used to identify the intangible Aboriginal cultural heritage values and connection to Country by Traditional Owners including stories and song lines. The assessment findings are used to inform the Aboriginal cultural heritage impact assessment for the Environment Effects Statement (EES) and the Cultural Heritage Management Plans.

When conducting field work for the cultural values assessments, a group of Elders and other Traditional Owners and cultural heritage advisors will visit the identified areas on the property and discuss their findings and record their observations of the intangible cultural heritage or cultural values associated with the area. These surveys generally involve visual inspections only and no ground-disturbing activities.

Cadastral surveys identify the precise boundaries of each property parcel based on the public information available from Land Use Victoria. This information will be used to refine the project design including the easement, and siting of transmission towers and infrastructure, and may inform the easement compensation valuation. Typically, several land parcels can be surveyed in a day, therefore, the surveyors may only be at a site for a few hours.

The purpose of ecology ground-truthing field surveys is to establish if certain flora and fauna species or habitat are present, while also confirming the extent and significance of any population that is identified.  The findings will be used to confirm the potential impacts on biodiversity within and surrounding the proposed route, and ensure appropriate measures are taken during project design and construction to avoid and minimise impacts. 

Ecology ground-truthing surveys are conducted by using recording equipment to record animal calls over a period of time, or by physically observing and recording the presence of flora and fauna species, ecological communities and habitat. These surveys may need to be conducted at specific times of the year or times of the day or night depending on the species being investigated.  

AusNet occasionally conducts light detection and ranging (often known as LiDAR) and aerial mapping surveys to capture up-to-date imagery and mapping to inform project planning and the Environment Effects Statement.

Surveys can be conducted using either fixed wing aircraft or helicopters. We acknowledge that aerial surveys using helicopters in particular can cause disturbance to people, animals and farming operations. We will advise you before we undertake an aerial survey over your property so you can make any necessary arrangements for your operations and livestock. All aerial surveys are undertaken in accordance with Civil Aviation Safety Authority regulations. These surveys are generally undertaken at no lower than 1000 feet over built-up areas and 500 feet above other areas. When flying between survey areas, the helicopter will fly at an appropriate height to minimise disruption.

The purpose of geotechnical work is to investigate the soil composition and validate the desktop analysis of geologic conditions to inform project planning and design. This work is done by taking soil samples using boreholes and test pits. Upon completion, the boreholes and test pits will be re-filled, as per landholder requirements.  

The purpose of historic heritage surveys is to identify or confirm the location of artefacts or archaeological sites. These surveys are undertaken in areas identified as having potential historic heritage values that are significant to Victoria’s European cultural history.

Historic heritage surveys will typically begin by walking over the site and making observations. Photographs may be taken to record any potential findings. If the archaeologist(s) considers the site requires further investigation, small-scale excavations may be undertaken. 

The purpose of the soil resistivity tests is to determine the conductivity of the soil, essentially how easily earth return current can flow through the ground. This data will then be used to design the earthing system for the proposed Western Renewables Link transmission line.   

Stainless-steel earth stakes are put into the ground at a maximum depth of 200mm, at various spacings from 0.5m to 64m along two transverses, 90 degrees apart from a centre point.  The testing causes minimal disturbance apart from small holes from where the earth stakes are placed.