Bushfires have a wide variety of causes. There are natural causes, such as lightning strikes; and accidental causes, such as sparks from farm machinery, incinerators, power lines, vehicle crashes, escapes from burning off and camp fires.
Unfortunately, a number of bushfires are also started deliberately.
Most bushfires occur during the Bushfire Danger Period, from October 1 to March 31 each year. As the dates below indicate, some bushfire seasons are worse than others.
1957: Bushfires in the Blue Mountains area driven by gale force winds destroyed 25 homes, shops, schools, churches and a hospital.
1964/65: Major fires occurred in the Snowy Mountains, Southern Tablelands and outer metropolitan area. The Chatsbury/Bungonia fire covered 250,000ha and destroyed the village of Wingello. Three lives were lost. In March the Tumut Valley fire burnt 80,000ha.
1968/69: Widespread damage occurred over much of the eastern part of the State. Major fires at Wollongong burnt rainforest, destroyed 33 homes and five other buildings. Fires in the lower Blue Mountains were fanned by 100km/h westerly winds and destroyed 123 buildings. Three lives were lost.
1969/70: The Roto fire burnt some 280,000ha in a three week period.
1972/73: The south-eastern corner of the State suffered the worst fires since 1968 with over 200,000ha burnt. The Burrinjuck fire burnt 16,000ha and was reported to have travelled 19km in three hours, denuding a hillside in its path.
1974/75: The severest season for perhaps 30 years in the far west with 3,755,000ha burnt, 50,000 stock lost and 10,170km of fencing destroyed. 1.5 million ha were burnt in the Cobar Shire in mid-December and 340,000ha in the Balranald fire. The Moolah-Corinya fire burnt 1,117,000ha and was the largest fire put out by bush firefighters. Its perimeter was over 1,000km.
1976/77: In early December, 9,000ha were burnt and three homes destroyed in Hornsby Shire, and 65,000ha were burnt in the Blue Mountains.
1977/78: In the Blue Mountains area 49 buildings were destroyed and 54,000ha burnt. Sydney suburbs up to 60km away were showered with fallout of blackened leaves.
1978/79: Serious fires occurred in the Southern Highlands and South West Slopes regions. Over 50,000ha were burnt, five houses were destroyed and heavy stock losses were inflicted.
1979/80: Following severe drought conditions over most of the State, major fires were widespread. In Mudgee Shire, 55,400ha were burnt and one life was lost. 9,000ha were burnt in Warringah Shire and 14 houses lost. Fires occurred in the majority of council areas within the State burning a total of over 1 million ha.
1982/83: $12 million worth of pine plantation was destroyed in southern NSW in a fire, which burnt 25,000ha in only two and a half hours. The Grose Valley fire burnt 35,000ha.
1984/85: This was the worst fire season for ten years in the grassed western areas of the State. On Christmas Day more than 100 fires were started by lightning strikes and 500,000ha burnt as a result. The largest fire was at Cobar in mid-January with 516,000ha burnt. During the season there were 6,000 fires State-wide, 3.5 million ha burnt, four lives lost, 40,000 stock lost and $40 million damage.
1987/88: Over 115,000ha were burnt in the Bethungra and Warurillah/Yanco fires with three lives lost at the Bethungra fire. Major fires also occurred in the south eastern part of Kosciusko National Park where 65,000ha were burnt in the Park and surrounding areas.
1990/91: In November fires raced through the council areas of Hay and Murrumbidgee, claiming nearly 200,000ha of prime grazing land, destroying 100,000 sheep and hundreds of kilometres of fencing. Just one week later 80,000ha of land were burnt as fires claimed another 76,000 sheep and 200 cattle in Hay and Carrathool Shires. On December 23, hundreds of fires were reported across the State with eight emergency declarations made in the Hornsby, Ku-ring-gai, Cessnock, Hawkesbury, Warringah, Wollondilly, Gosford and Wyong council areas. Eight homes were lost in these fires.
1991/92: On October 16, two lives were lost at Kenthurst in the Shire of Baulkham Hills. Emergency declarations were made for the councils of Baulkham Hills, Gosford City, Wyong Shire and Lake Macquarie. Nearly 2,500 bushfirefighters battled more than 30 blazes around the State. 14 homes were destroyed.
1993/94: In late December 1993, a series of fires began on the north coast and in the Hunter Region. As weather conditions continued to deteriorate, fire occurrence spread from the Queensland border to Batemans Bay. In excess of 800 fires started between December 27, 1993 and January 16, 1994. Over 800,000ha were burnt.
All areas affected had previously been subject to wildfires, but never before had they burnt simultaneously. Resources from across Australia and New Zealand were utilised, resulting in a firefighting effort larger than any previously experienced in the country. At the height of the exercise over 20,000 firefighters were deployed. Four lives were lost and 206 homes destroyed.
1997/1998: There were major fires in the Burragorang, Piliga, Hawkesbury, Hunter, Shoalhaven, Central Coast and Sydney's south (particularly Menai) that proved difficult to contain and suppress, and posed a major threat to communities, their assets and the environment.
However the fires were brought under control in a timely manner with only relatively minor property damage. There were in excess of 250 significant fires, and:
The principle duration was 16 days, though fires started in late November 1997 and continued until 28 Feb 1998.
2001/2002: The initial impact of seven “Bushfire Emergencies” occurred during the period 29 October 2001 to 9 November 2001 in the areas of Cessnock, Gosford, Gloucester, Kempsey, Wyong, Greater Taree and Singleton.
The second spate of 5 “Bushfire Emergencies” commenced at 1500 hours on 3 December 2001 with the declaration of the Blue Mountains Rural Fire District. The fires generally started as a result of a severe dry thunderstorm with many lightning strikes on the Great Dividing Range and to the west.
The same storm reached the coastal areas north of Sydney with heavy rain and hail accompanied by very strong winds, causing significant storm damage. Major fires occurred in Blue Mountains/Lithgow, Hawkesbury, Narromine, Wollondilly/Wingecarribee and Cabonne over the 21 days up to 24 December 2001.
On 24 December 2001, due to increased fire activity, proximity to Sydney, threat to residential property and apparently deliberately lit fires, there was significant media and public interest. On 25 December 2001 a number of interstate offers of assistance were made. There were 26 “Bushfire Emergency” declarations incorporating 48 local government areas.
Some districts had several declarations due to new fire outbreaks. 23 days later the significant "emergency" was declared over by the Commissioner at a press conference, although 11 section 44s were still to be declared out.
Following are some statistics from 24 December 2001 to 16 January 2002:
Weather maxima (across all firegrounds) included: