Barwon South West

Bushfire risk

Barwon South West’s long-term bushfire risk regional planning target is 60 per cent.

The figure below shows the Barwon South West region’s bushfire risk profile for 1980–2021 and projected changes in bushfire risk until 2024. It shows bushfire risk in the Barwon South West region:

• was 62 per cent in 2020–21, down 10 percentage points from a projected level of 72 per cent (if there were no major bushfires or fuel management)
• decreased 6 percentage points from 68 per cent at the end of 2019–20
• is projected to fall to 44 per cent by 2024 if we implement the entire Joint Fuel Management Program and there are no major bushfires, noting it would increase to 71 per cent without any fuel management activity or major bushfires. Implementing the entire program would keep bushfire risk levels below the long-term Barwon South West region planning target of 60 per cent.

Priority areas for planned burning include the Surf Coast and Otway hinterland, the eastern Otways, and across the Far South West fire district. Mechanical treatments will continue to target difficult-to-burn areas along the Great Ocean Road. Other key activities include finalising the construction of a strategic fuel break network adjacent to communities in the Otways and targeted community preparedness actions in high-risk settlements along the Great Ocean Road.

Ecosystem resilience

The figure below shows the tolerable fire interval (TFI) status of vegetation on public land in the Barwon South West region since 1980. It shows that in 2020–21:

• 23 per cent of the vegetation was below minimum TFI, a figure maintained from the previous reporting period
• the proportion of vegetation within TFI was maintained at 40 per cent
• the proportion of vegetation above maximum TFI was maintained at 12 per cent. This continues the positive trend of post-fire regeneration since 2015, supported by our fire management strategies that aim to minimise the impacts of fuel management on species abundance while improving ecological resilience with ecological burning.

In 2020–21, less than 1 per cent of the vegetation burnt by bushfire or planned burning was below minimum TFI. At a finer scale, the region continued to explore improving ecosystem resilience by delivering fine-scale mosaic burning at Anglesea, Carlisle and Kentbruck heaths, as well as ridgeline burning in the Otways. We are currently looking at ways to improve monitoring and reporting of these finer scale techniques and their positive contribution towards maintaining or improving ecosystem resilience in the Barwon South West.

The figure below shows the growth stage structure (GSS) status of vegetation on public land in the Barwon South West region since 1980. It shows that in 2020–21:

• about 6 per cent of the vegetation was in the juvenile growth stage, compared to 5 per cent in 2019–20, a 1 percentage point increase on juvenile growth
• about 10 per cent of the vegetation was in the adolescent growth stage, compared to 13 per cent in 2019–20, a decrease in adolescent growth of 3 percentage points
• the proportion of vegetation in the old growth stage moved from 17 per cent to 15 per cent, a 2 percentage point decrease, and the proportion in the mature growth stage moved from 39 per cent to 36 per cent, a 3 percentage point decrease.

Some species in the Barwon South West region, such as the Swamp antechinus, prefer older growth stages and the habitat attributes associated with them. Others, such as the Heath mouse, prefer vegetation that has seen fire more recently. The Barwon South West region continues to improve understanding of faunal species preferences for different growth stages at a landscape and fine scales by collecting and analysing field and remote-sensed data.

Fuel management delivery

The positive trends in bushfire risk reduction and ecosystem resilience reflect our carefully considered fire management strategies, which aim to minimise bushfire risk while also minimising the impacts of fuel management activities on species abundance. Barwon South West has also worked to further improve ecological resilience by applying ecological burning in the landscape.

Table 1: Fuel management activities, Barwon South West region, 2020–21

During 2020–21, we treated 9,589 hectares by planned burning in the Otway fire district, and 6,094 hectares in the Far South West fire district. Accounting for annual fuel re-accumulation, this translated to a 9–10 per cent risk reduction.

The program took a 365-day approach to fuel management, involving planned burning and mechanical fuel treatments, and commenced with winter heath burning around Anglesea and Nelson. Had we not set out to take all opportunities throughout the year, we would not have achieved the level of risk reduction we did. Given the damp summer, both districts started burning in February 2021 and continued to late May.

Some particularly complex and difficult burns significantly reduced bushfire risk to the Otway Coast communities of Lorne, Fairhaven, Aireys Inlet, and Anglesea. In the Far South West fire district, planned burns around Nelson delivered great results for the Gorae and Bolwarra settlements north of Portland.

Community engagement activities included direct landholder contact, social media, and widespread use of variable message signage on traffic routes.

Strategic fuel breaks up to 40 m wide were constructed with heavy mulching equipment along the Great Ocean Road and around coastal settlements including Lorne, Moggs Creek, Aireys Inlet, and Anglesea. Extensive planning and engagement were required to support this construction as well as many other activities on public and private land. The benefits include greater community safety, and easier and safer planned burns, while managing risks to values important to local communities - building resilience as we adapt to a changing climate.

Our planned burning program aims to enhance ecological attributes and outcomes, and we monitor the effects of fire on plants and animals including their diversity and abundance.

In the Far South West fire district, we continued to focus on woody weed and pine wilding invasion of heathy woodlands, which is critical habitat for the South-eastern red-tailed black cockatoo. In the Carlisle Heath area, we actively monitored small mammal populations.

The region’s 2020–21 fuel management program required more than 10,000 person days and received resourcing support from across Victoria. A big thank you to all involved in delivering a safe, successful program.

Page last updated: 23/12/21