Interactive EIS map | Hunter Transmission Project

This map provides details for the EIS and amended project for the Hunter Transmission Project (HTP). Use this map to explore how HTP may relate to your property or local area.

You can search for your address or zoom into your area to view key project features. This map provides an overview of the project and does not confirm individual property impacts.

Information presented is indicative and will continue to be refined as the project progresses. If you have questions, please contact the project team - htp@energyco.nsw.gov.au / 1800 645 972 or visit the website for more information.

Overview

This section provides a summary of the Hunter Transmission Project (HTP), outlining its critical role in NSW's energy future and the key infrastructure components involved.

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The Hunter Transmission Project is both a critical State significant infrastructure (CSSI) project and a Priority Transmission Infrastructure Project (PTIP). As the remaining coal-fired power stations close, the Hunter Transmission Project is critical for energy security in New South Wales (NSW).

The Hunter Transmission Project includes:

a new overhead 500 kilovolt (kV) double circuit transmission line of around 110 kilometres
two new switching stations (Bayswater South and Olney)
upgrades to the existing Bayswater and Eraring substations
adjustments and upgrades to existing transmission lines
property adjustment works to facilitate access to the transmission lines and switching stations
utility adjustments required for the construction of the transmission network infrastructure
ancillary works to support construction including road upgrades, establishment of new access tracks and upgrades to existing access tracks, construction support sites (some with temporary worker accommodation), and other construction facilities such as laydown areas.

The Hunter Transmission Project corridor runs mostly through power station, mining and government land between Bayswater and Broke. It then traverses the Pokolbin, Corrabare, Watagan and Olney State forests where it joins the existing 500 kV transmission line running between Eraring and Kemps Creek in Western Sydney.

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Mines

NPWS reserves / national & state conservation areas

State forests / recreation areas

The Hunter Transmission Project corridor runs mostly through power station, mining and government land between Bayswater and Broke, then traverses the Pokolbin, Corrabare, Watagan and Olney State forests to join the existing 500 kV transmission line between Eraring and Kemps Creek in Western Sydney.

The Energy Corporation of New South Wales (EnergyCo) selected a corridor that sought to balance different land uses in the Hunter and minimise impacts on people and the environment.

The corridor avoids sensitive land uses including vineyards, tourist areas, State forest recreation areas, Watagans and Werakata National Parks, Corrabare South and Warrawolong Flora Reserves, Werakata State Conservation Area and Sugarloaf State Conservation Area.

It also avoids other high conservation value areas including existing biodiversity offset sites and intact remnants of threatened ecological communities such as the Central Hunter Valley Eucalypt Forest and Warkworth Sands Woodland, which provide critical habitat for the Regent Honeyeater and Swift Parrot. Significant Aboriginal cultural heritage sites are avoided or impacts minimised, including rockshelters, cultural places, grinding grooves and Flat Rock Lookout.

Biodiversity

Protecting the natural environment is a key priority. This section details the revised assessment of potential impacts on local biodiversity prepared for the amended project, including native vegetation, threatened species and threatened ecological communities, and outlines measures for avoidance and mitigation.

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NPWS reserves / national & state conservation areas

Native vegetation extent

During corridor selection, EnergyCo prioritised avoidance of high conservation value areas, including Watagans and Werakata National Parks, Corrabare South and Warrawolong Flora Reserves, existing biodiversity offset sites, and intact remnants of the Central Hunter Valley Eucalypt Forest and Warkworth Sands Woodland threatened ecological communities. These communities support threatened species and critical habitat for the Regent Honeyeater and Swift Parrot.

Following selection, the transmission line design underwent iterative refinement based on ecological field surveys and site constraints, resulting in substantial further avoidance and minimisation of biodiversity impacts. Cumulatively, these refinements are expected to reduce clearing of native vegetation by over 200 hectares, including avoidance of more than 100 hectares of threatened ecological communities and important habitat for a range of serious and irreversible impact entities.

Further design changes were made as part of the amended project to continue to avoid and minimise impacts on biodiversity. This included refining the areas of impact on threatened ecological communities and important breeding habitats for threatened frog species, notably Littlejohn’s Treefrog and Stuttering Frog.

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Disturbance Area A (full clearing)

Disturbance Area A (20 m centreline)

Disturbance Area B (partial clearing)

Hazard tree zone (HZ)

Disturbance area: No clearing zone areas

A disturbance area has been used to assess potential impacts on biodiversity values. It includes the following categories:

Disturbance area A – the area where vegetation would be completely removed.
Disturbance area A (centreline) – a 20‑metre‑wide centreline area between transmission towers where all vegetation would be removed.
Disturbance area B – the area within the transmission line easement, excluding disturbance area A and disturbance area A (centreline), where partial clearing would be undertaken.
Hazard tree zone (HZ) – areas where hazard tree management would occur during operation.

No clearing zones have also been defined and refer to the areas within the transmission line easement where vegetation removal is not required.

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Threatened ecological communities

While significant efforts have been made to avoid and minimise impacts, vegetation clearing is still required in some areas of high biodiversity value, including threatened ecological communities and threatened species habitat listed under the NSW Biodiversity Conservation Act 2016 (BC Act) and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).

BC Act: 228.23 hectares aligning with seven endangered ecological communities.
EPBC Act: 166.55 hectares aligning with three critically endangered ecological communities.

One threatened ecological community is identified as a potential serious and irreversible impact entity: approximately 4.31 hectares of Hunter Floodplain Red Gum Woodland in the NSW North Coast and Sydney Basin Bioregions EEC.

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Threatened flora records

As per the revised biodiversity assessment for the amended project, construction could directly impact 38 threatened flora species: 24 listed under both the BC Act and EPBC Act, 12 under the BC Act only, and 2 under the EPBC Act only. Seven species are potential serious and irreversible impact entities, including Eucalyptus fracta (Broken Back Ironbark), Genoplesium branwhiteorum (Charmhaven Midge Orchid), Genoplesium insigne (Variable Midge Orchid), Rhizanthella slateri (Eastern Australian Underground Orchid), Rhodamnia rubescens (Scrub Turpentine), Rhodomyrtus psidioides (Native Guava) and Thelymitra adorata (Wyong Sun Orchid).

The location of some threatened flora records on the interactive map has been generalised due to the sensitivity of these species.

Construction could directly impact 28 threatened fauna species: 15 listed under both the BC Act and EPBC Act, and 13 under the BC Act only. Eight species are potential serious and irreversible impact entities, including the Regent Honeyeater, Large-eared Pied Bat, Hunter Valley Delma, Swift Parrot, Littlejohn’s Tree Frog, Stuttering Frog, Brush-tailed Rock-wallaby and Sooty Owl.

Aboriginal heritage

EnergyCo acknowledges the Traditional Owners and Custodians. This section outlines the addendum Aboriginal cultural heritage assessment for the amended project, including the revised archaeological assemblage, the assessment approach and the potential impacts identified.

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ACHA study area

The Aboriginal Cultural Heritage Assessment addendum was prepared in accordance with the Guide to Investigating, Assessing and Reporting on Aboriginal Cultural Heritage in NSW (OEH 2011) and the Code of Practice for Archaeological Investigation of Aboriginal Objects in NSW (DECCW 2010).

Feedback received during exhibition of the EIS resulted in changes to how the archaeological assemblage of the amended project impact area was defined and assessed. This included recognising sites identified in the EIS but not relocated during field surveys, including sites immediately adjacent to the project impact area, considering cultural materials that may be affected through the cultural values mitigation strategy, and separating background scatter sites into individual items for assessment and management.

Additional archaeological field survey and test excavation were also undertaken for the amended project, including areas previously inaccessible during the EIS process. Field survey achieved 82.5 per cent coverage of the amended project impact area, compared with 72 per cent for the exhibited project impact area.

Rather than assuming direct impacts to all Aboriginal objects, sites and places within the amended project impact area, the addendum applies the disturbance area approach used in the biodiversity assessment to provide a more accurate estimate of likely direct and indirect impacts.

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ACHA study area

The revised archaeological assemblage of the amended project impact area now consists of 452 Aboriginal objects, sites and places. This includes 303 within the amended project impact area, 146 outside but within 55 metres of it, and three rockshelters outside the amended project impact area that may be affected through Aboriginal-led research under the cultural values mitigation strategy.

Consistent with the EIS, the project remains committed to avoiding a large number of Aboriginal objects, sites and places of high and/or moderate significance. This has increased from five sites proposed for avoidance in the exhibited ACHA to 20 in the addendum.

Applying the disturbance area approach, the amended project would potentially completely or partially impact 217 Aboriginal objects, sites and places within the disturbance area, indirectly affect 12 Aboriginal objects, sites and places within or within 55 metres of the amended project impact area but outside disturbance areas, and partially impact three rockshelters outside the amended project impact area through Aboriginal-led research. The remaining 69 objects, sites and places within the amended project impact area but outside the disturbance area, and 131 objects, sites and places outside but within 55 metres of the amended project impact area, are unlikely to be impacted.

Of the 117 hectares of the predicted Warkworth Sands system within the amended project impact area, around 50 hectares, or 43 per cent, are located outside the disturbance area and would not be impacted by project construction.

Landscape and visual

The visual character of the region is an important consideration. This section outlines the amended landscape character and visual assessment for the project, including impacts on landscape character zones, public viewpoints and private viewpoints.

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Sensitive receivers

The landscape character and visual study area was determined in accordance with the Transmission Guideline, Technical Supplement for Landscape Character and Visual Assessment (DPHI 2024). It includes: a landscape character assessment study area encompassing all areas within 5 km of the project, and a visual assessment study area encompassing all areas within 1.625 km of the corridor (based on a maximum tower height of 85 m). Construction support sites outside the landscape character study area were also considered for temporary impacts.

Sensitive receivers include dwellings, historic homesteads, tourist and visitor accommodation, places of worship, town centres and CBDs within the visual assessment study area.

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Landscape character zones (LCZ)

The landscape character assessment divided the study area into 12 landscape character zones (LCZs) based on similar topography, vegetation and land use.

In the EIS it was assessed that during the daytime, the project would have a moderate impact on three LCZs: LCZ 7 (Wollombi Brook rural valley), LCZ 8 (Forested hills) and LCZ 11 (Narrow rural valleys). At night, a moderate impact was predicted at LCZ 12 (Managed forestry) at the proposed Olney switching station due to occasional localised lighting. All remaining LCZs would experience low to negligible impacts during construction and operation.

As part of the amended project, the temporary worker accommodation at the Wollombi Road construction support site would increase the landscape character impact within LCZ 11 (Narrow rural valleys) from moderate to high during daytime construction. At night during construction, the temporary worker accommodation would operate 24/7 and include external lights over a large geographic area which would increase the landscape character impact from negligible to high. However, during operation, this is reduced to negligible. All other LCZs remain at low to negligible impacts during construction and operation.

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Public viewpoints (incl. Cessnock Rd 07)

In the EIS, a simple visual assessment was undertaken for 12 public viewpoints representing views to the project. Six had potential low visual impact and six had potential moderate or high impact. A detailed assessment of the latter group (Putty Road, Cessnock Road, Wollombi Road (east), Flat Rock Lookout, Olney Headquarters campground and picnic area, and Watagan Forest Road) found that Cessnock Road (07) would have a moderate visual impact; the remaining public viewpoints would have a low visual impact.

The findings for the amended assessment are consistent with the EIS. No additional public viewpoints were selected and there are no changes in visual impact during operation. However, additional potential visual impacts would occur at public viewpoints 08 and 09 on Wollombi Road during construction due to the addition of a larger construction support site and temporary worker accommodation adjacent to Wollombi Road (looking east and west), west of Millfield. Construction impacts are temporary and the construction support sites will be decommissioned and rehabilitated as required following construction.

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Private viewpoints (moderate/low)

Private viewpoints associated with rural dwellings would experience visual impacts from the introduction of permanent infrastructure.

In the EIS, 68 dwellings were assessed, 34 had potential low impact, 22 potential moderate impact and 12 potential high impact in the simple assessment. Detailed assessment found moderate impacts for six private viewpoints (IDs 238, 465, 466, 467, 2920 and 2929); the remaining viewpoints would have low or no visual impact.

Private viewpoint assessments have been updated for the proposed realignment of the transmission line at Mount Thorley and Gouldsville.

Simple visual assessments for the amended project were undertaken for 12 dwellings at Mount Thorley. Four private viewpoints would have potential high visual impact, four private viewpoints would have potential low visual impact and four private viewpoints were eliminated as they are now outside the visual study area and would have no visual impact. Detailed assessment found moderate impacts for one private viewpoint (ID 2920) and low visual impact for three private viewpoints (ID 251, ID 277 and ID 3525). The moderate visual impact for ID 2920 is consistent with the visual impact rating found in the EIS.

An updated detailed assessment and photomontage for the two most affected private viewpoints (ID 2929 and ID 2928) within the vicinity of Gouldsville were consistent with the findings of the EIS. The assessment found the potential for moderate visual impact from ID 2928, which is consistent with the EIS, and an increase to low visual impact from ID 2929.

Traffic and transport

Managing construction traffic effectively is crucial for community safety and minimising disruption. This section summarises the amended traffic and transport assessment, including construction routes, vehicle movements, oversize and overmass deliveries, access roads and tracks, and proposed road and intersection upgrades.

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Construction traffic routes

Oversize–overmass (OSOM) routes (Within study area)

Construction of the project would generate both light and heavy vehicle movements, including some oversize/overmass deliveries, using national, State, regional and local roads as well as roads within NSW State forests and conservation areas. During the morning peak, up to 201 heavy and 300 light vehicle movements are expected; during the afternoon peak, around 172 heavy and 240 light vehicle movements are expected. Movements would be distributed across identified routes between work sites and construction support sites (Hebden Road, Pikes Gully Road, Gouldsville Road, Wollombi Road and Freemans Drive). OSOM deliveries include transformers to Eraring substation (≈7 deliveries), reactors to Bayswater South switching station (≈3) and auxiliary services buildings to each new switching station (≈2). A road capacity assessment indicates most routes would operate well even at peak times, with the New England Highway (west of Lemington Road) and Freemans Drive (south of Martinsville Road) near capacity or satisfactory.

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Access tracks – new

Access tracks – existing (upgrade)

Access tracks – existing (no upgrade)

Entry points

The project would use a mix of new and existing access tracks on private properties. Some existing tracks require upgrades to accommodate construction vehicles and machinery and to provide safe access during construction and operation. Where existing tracks are unsuitable or terrain prevents access along the corridor, new tracks would be constructed—preferably within already‑disturbed areas. In State forests, traffic control and passing bays are proposed to improve capacity and safety.

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Proposed road and intersection upgrades

To safely accommodate construction traffic and oversized deliveries, upgrades to public roads and key intersections are proposed along construction routes. These will be confirmed with the relevant road authorities and will require approvals under the NSW Roads Act 1993, where relevant.

Noise and vibration

Minimising noise and vibration is important for nearby communities. This section outlines the revised assessment of potential noise and vibration impacts for the amended project during both construction and operation.

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Noise catchment areas (NCA)

Sensitive receivers (potentially impacted residents/ facilities)

The noise and vibration study area reflects the possible distance within which sensitive receivers may experience noise and vibration from the project. It is defined by noise catchment areas (NCAs), which group receivers with similar noise environments around project components and activities. Sensitive receivers are primarily residential dwellings on agricultural properties, with other categories including commercial/industrial premises and other sensitive land uses (e.g. places of worship, recreation areas, campgrounds).

Additional sensitive receivers have been included in the NVIA addendum compared with those assessed as part of the exhibited NVIA, including sensitive receivers in proximity to the amendments and refinements of the project and sensitive receivers not previously included in the exhibited NVIA that were identified through submissions received during exhibition of the EIS.

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Noise monitoring locations & baseline

Existing noise levels are typical of rural areas and dominated by natural sources such as wildlife and weather. Unattended and short‑term attended ambient noise monitoring was carried out at six locations selected to represent background levels across the project area. Publicly available monitoring data from other projects were used to supplement measurements, given the large extent of the study area.

These results were used to determine project‑specific noise management levels—the thresholds used to assess and manage potential noise impacts at sensitive receivers.

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Construction impacts

Construction activities—including plant and equipment operation, construction traffic and workforce accommodation facilities—may temporarily impact sensitive receivers. On‑site monitoring and modelling indicate that short‑term exceedances above typical background levels may occur during peak construction activities. Exceedances are predicted at sensitive receivers within all NCAs apart from NCA 1 (Liddell and Bayswater), NCA 7 (Pokolbin) and NCA 10 (Cessnock). Nearby receivers may also experience short‑term vibration impacts. A noise and vibration management plan will be implemented to minimise impacts.

The amended project would result in a total of 603 potentially impacted sensitive receivers. While 30 sensitive receivers have been newly identified as a result of the amended project, 30 sensitive receivers are no longer impacted in comparison to the EIS, resulting in no net change in sensitive receivers. However, five additional sensitive receivers would be highly affected by the amended project in comparison to the EIS.

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Impacted receivers

Operational noise from the transmission line and switching stations is expected to be low. Receivers are unlikely to experience noise or vibration impacts during fair‑weather conditions. Switching station noise is predicted to be well within acceptable levels. The high‑voltage line may generate a soft hum that is more detectable under certain weather conditions (e.g. light mist or rain); conservatively, up to 12 receivers closest to the corridor would experience operational noise exceedances during such events. An additional two receivers would be impacted in comparison to the EIS.

Project overview

Avoidance of environmentally sensitive areas

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Avoidance and minimisation of biodiversity impacts

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Disturbance area

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Threatened ecological communities

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Threatened flora

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Threatened fauna

Assessment approach

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Archaeological assemblage and potential impacts

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Study area and sensitive receivers

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Landscape character

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Public viewpoints

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Private viewpoints

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Construction traffic

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Access tracks

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Proposed road and intersection upgrades

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Study area and sensitive receivers

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Noise monitoring and noise management levels

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Construction noise impacts

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Operation noise impacts

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Avoidance and minimisation of biodiversity impacts

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Disturbance area

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Threatened ecological communities

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Threatened flora

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Threatened fauna

Assessment approach

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Archaeological assemblage and potential impacts

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Study area and sensitive receivers

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Landscape character

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Public viewpoints

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Private viewpoints

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Construction traffic

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Access tracks

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Proposed road and intersection upgrades

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Study area and sensitive receivers

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Noise monitoring and noise management levels

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Construction noise impacts

Operation noise impacts

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