3.3 Impacts of Black Summer on the ACT
The 2019–20 bushfire season had significant impacts on the ACT’s environment and community. Large areas of native ecosystemsA biological community of interacting living and non-living things. were burnt, air pollution from bushfire smoke reached extreme levels, and cultural heritage sites were damaged or destroyed.
Environmental impacts
The Orroral Valley fires burnt around 80% (82,700 hectares) of Namadgi National Park, and 22% (1,450 hectares) of Tidbinbilla Nature Reserve. These protected areas are home to important ecosystemsA biological community of interacting living and non-living things. and provide habitat for many species, including endangered plants and animals.
Burnt and burnt again
About 90% of the area burnt in the Orroral Valley bushfire was also burnt in the 2003 bushfires, just 17 years earlier. This makes the environmental impact of the Orroral Valley bushfire especially concerning. More frequent bushfires make it harder for some species to recover.
This map shows the area burnt in the 2003 bushfires (yellow), the 2020 bushfires (red), and the area burnt by both fires (orange).
Data sourced from: Environment, Planning and Sustainable Development Directorate.
Before the Orroral Valley bushfire even started, severe drought conditions in the ACT had already put major stress on plants, animals, and ecological communities.
The fire itself then had devastating impacts on biodiversityThe variety of all life and living processes in the environment., with millions of plants and animals lost. Many plants and animals that survived the actual fire are now threatened by post-fire conditions. With so much vegetation destroyed, there is less habitat and food available for native species. There is also a higher risk of weeds and invasive predators. These factors all make it harder for native species to recover from severe fires and, in extreme cases, can lead to major changes in ecosystemsA biological community of interacting living and non-living things..
The bushfires also significantly impacted aquatic ecosystemsA biological community of interacting living and non-living things.. After the fire, intense rain broke the long drought. With so much water running off recently burnt areas, many waterways were degraded by poor water quality and the loss of aquatic and riparianThe land and vegetation along the edges of creeks, rivers, lakes and wetlands. habitat.
To find out more about how fires can affect the environment and biodiversityThe variety of all life and living processes in the environment., click on the 
symbols on the picture below.
Bushfire runoff and sediment in the Cotter River at Black Sallee Flat on 19 February 2020. Source: Mark Jekabsons.
Some of the threatened ACT fauna impacted by the Orroral Valley bushfire include:
- The Gang-gang Cockatoo (ACT’s faunal emblem) had nearly 20% of its habitat burnt by the fires.
- The Southern Greater Glider and Yellow-bellied Glider lost large areas of mature trees that they need for nesting hollows and food.
- The Broad-toothed Rat’s habitat was impacted when fires burnt Alpine Bogs and Fens in Namadgi National Park.
- The populations of Mountain Galaxias fish, Reiks Crayfish, and the Two-spined Blackfish were greatly impacted by bad water quality after the fire.
For more information on some of these species, explore the stories below.
Regrowth and recovery
Source: Environment, Planning and Sustainable Development Directorate.
Vegetation recovery from the 2020 Orroral Valley fire has been mixed. Some plant species are recovering well, while others are struggling to bounce back.
Ecological communities like Natural Temperate Grasslands have recovered quickly. About 75% of Natural Temperate Grassland in Namadgi National Park was burnt in 2020. Just a year after the bushfires, there was little difference between sites that had been burnt versus those that hadn’t. Click through the photos below to see the rapid recovery of Natural Temperate Grassland after the fires.
However, not all plant species are showing signs of recovery. The recovery of Alpine Ash is particularly concerning. These trees are killed by intense fire and must regenerate from seed. We don’t know how well Alpine Ash will recover after being burnt by two intense fires in 2003 and 2020, only 17 years apart. This short amount of time between fires is unlikely to be long enough for Alpine Ash to mature and produce seeds. In Namadgi, many young Alpine Ash trees that germinated after the 2003 fires were killed by the Orroral Valley bushfire.
Fortunately, some important stands of Alpine Ash were not affected by the 2020 bushfires, with one-third of Namadgi National Park’s Alpine Ash forest thankfully unburnt.
Impacts on the ACT community
For much of Black Summer, the ACT was blanketed by a thick layer of bushfire smoke – first from fires in surrounding NSW, and later from the Orroral Valley fire within the ACT itself. Throughout the 2019-20 bushfire season, the ACT community experienced the worst air quality recorded in Territory history, and on some days had the worst air quality of any city in the world (see Air pollution).
Over the 91 days of summer, air pollution monitored at the Monash Station in Tuggeranong exceeded national health standards on 56 days, with 42 of these days above the hazardous rating. On 1 January 2020, PM2.5Particles in air that are 2.5 micrometres or less in diameter. pollution levels were around 25 times the threshold to be considered hazardous. During days of severe air pollution, Canberrans were advised to stay indoors whenever possible.
This graph shows the impacts of the NSW bushfires on ACT’s air quality. The pink dotted line shows the level at which air quality is classed as hazardous to human health. The data shows that air quality exceeded the hazardous rating many times over the summer, sometimes by a very significant amount.
Data sourced from: ACT Health Directorate.
This extreme air pollution had both physical and mental health impacts on the Canberra community.
Bushfire smoke caused an estimated 31 excess deaths in the ACT, as well as 318 hospital admissions. 97% of people surveyed living in and around the ACT during Black Summer reported that the smoke had impacted their physical health. People experienced eye and throat irritation, coughing, respiratory issues like wheezing and breathlessness, and headaches. 31% reported that an existing physical health problem had worsened, and 16% had difficulty managing an existing health condition as a result of smoke and/or fires. Hospitalisations for conditions like asthma increased on or directly after days with worse air pollution.
The prolonged smoke and ever-looming threat of the bushfires also impacted people’s mental health and wellbeing. One study found that 36% of ACT residents often felt anxious or worried during the bushfire period, and a further 52% reported feeling anxious occasionally. Disruptions to normal routines because of the heavy smoke also had consequences. Being stuck inside, unable to exercise outdoors or catch up with friends further contributed to feelings of stress, anxiety and uncertainty.
Explore the stories below to learn more about the impacts of Black Summer on the Canberra community.
