Bushfire risk
Barwon South West’s long-term bushfire risk regional planning target is 60%.
The figure below shows the Barwon South West region’s bushfire risk profile for the period 1980–2020 and projected changes in bushfire risk until 2023. It shows bushfire risk in the Barwon South West region:
- is 68% in 2019–20, an increase of five percentage points from 63% at the end of 2018–19
- is projected to fall to 45% by 2023 if we implement the entire Joint Fuel Management Program (JFMP) and there are no major bushfires but would increase to 75% without any fuel management activity or major bushfires. This action will keep bushfire risk levels below the long-term Barwon South West region planning target of 60%.
Priority areas for planned burning include the Surf Coast and Otway hinterland as well as areas in the eastern Otways and across the Far South West. Mechanical treatments will continue to target difficult to burn areas along the Great Ocean Road In addition, other key activities include the construction of a strategic fuel breaks network adjacent to communities in the Otways as well as targeted community preparedness actions in high-risk towns along the Great Ocean Road.
Bushfire risk profile, Barwon South West Region, 1980–2023
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 2019–20:
- 23% of the vegetation was below minimum TFI, four percentage points less than in the previous reporting period
- the proportion of vegetation within TFI increased by five percentage points to 40%
- the proportion of vegetation above maximum TFI decreased by one percentage point to 12%. 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 2019–20, less than 1% of the vegetation burnt by bushfires or planned burning was below minimum TFI. Some areas may have experienced positive impacts from bushfires this season: for example, the bushfire in the Budj Bim Cultural Landscape burnt relatively coolly with low impact on the canopy and had a regenerative effect on the grassy-dominated understorey.
2019–20 also saw a highly successful winter mosaic burning program in the heathlands around Anglesea, Carlisle River and Mount Richmond. Many of these areas were long-unburnt. This burning has a regenerative effect on plants and animals. It also protects fire-sensitive gullies, which are refuges for several small mammal species (such as the threatened Swamp antechinus).
TFI status of vegetation on public land in Barwon South West region, 1980–2020
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 2019–20:
- about 5% of the vegetation was in the juvenile growth stage, an increase of two percentage points from the previous reporting period
- about 13% of the vegetation was in the adolescent growth stage, a decrease of one percentage point from the previous reporting period
- the proportion of vegetation in the old growth stage decreased by one percentage point to 17%, while the proportion in the mature growth stage remained about the same at 39%.
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. Our fire management strategies have been designed to account for these preferences in different areas of the landscape: we undertake planned burning in some areas and avoid it in others.
GSS status of vegetation on public land in Barwon South West region, 1980–2020
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 summarises the region’s fuel management activities in 2019–20.
Table 1: Fuel management activities, Barwon South West region, 2019–20
Fuel reduction | No. of treatments | Hectares |
|---|---|---|
Area treated by planned burning:
| 25 | 2,407 |
Area treated by non-burn fuel treatments:
| 53 | 3,815 |
Total area treated to reduce bushfire risk | 78 | 6,222 |
In 2019–20, early and mid-autumn saw wet conditions in the Otway fire district, which reduced opportunities to undertake planned burning along the Otway Coast. Ideal, stable, late autumn and early winter conditions enabled burning in heathland areas. In the Far South West fire district, conditions were generally more favourable throughout the year, so we could undertake a more comprehensive program of planned burning.
In 2019–20, we continued trialling operational approaches to enable us to broaden the conditions in which we can safely undertake planned burning. This included burning about 250 ha in a fine-scale mosaic pattern in the Carlisle and Anglesea heaths, as well as close to Nelson in the Far South West fire district.
We also continued to trial the aerial application of fire to ridgelines surrounded by moisture-retaining gully systems. Both approaches enable us to take advantage of burn windows of 3–5 hours. Over time, we expect this approach to form an important complementary part of our burn program, contributing to fuel reduction and landscape health outcomes.
The Far South West fire district undertook mechanical fuel treatments around the substation at Heywood and high voltage transmission lines in the Mt Clay State Forest. The substation and transmission lines provide power to South Australia and to the Portland Aluminium Smelter, which indirectly employs thousands of people in the region.
The Otway fire district mulching program was much bigger than in previous years, and it achieved several objectives including enabling future planned burns, reducing fuel hazard where burning was not possible and protecting assets within burns.
The Far South West fire district continued to support Gunditj Mirring and Gunditjmara Traditional Owners with the reintroduction of cultural burning into the world-heritage-listed Budj Bim Cultural Landscape. Wadawurrung Traditional Owners also contributed in winter to planned burning in the Anglesea Heath.
Page last updated: 25/11/20