|Formed||1 July 2006|
|Dissolved||30 June 2013|
|Jurisdiction||Government of Western Australia|
|Parent agency||Department of Conservation and Land Management|
The Department of Environment and Conservation (DEC) was a department of the Government of Western Australia that was responsible for implementing the state's conservation and environment legislation and regulations. It was formed on 1 July 2006 by the amalgamation of the Department of Environment and the Department of Conservation and Land Management.
The DEC was separated on 30 June 2013 forming the Department of Parks and Wildlife (DPaW) and the Department of Environment Regulation (DER), which both commenced operations on 1 July 2013.
On 1 July 2017 the DER amalgamated with the Department of Water and the Office of the Environmental Protection Authority, to become the Department of Water and Environmental Regulation,   while DPaW was merged with other agencies to form the Department of Parks and Wildlife. 
The department was managing more than 285,000 km2, including more than nine per cent of WA's land area: its national parks, marine parks, conservation parks, regional parks, state forests and timber reserves, nature reserves, roadside reserves and marine nature reserves. It provided visitor and recreation facilities at a sustainable level for many of these. 
It also supported or worked closely with the following authorities:
The total reportable visitation to DEC-managed lands and waters during the 2012-13 financial year was 16.02 million, with visitor satisfaction levels of 88%.
4,717 people were registered volunteers with the department in 2012-13 that helped in a range of projects across the state with 564,350 hours contributed.
DEC was responsible from 2007 to 2013 for protecting and conserving the state of Western Australia's environment; this included managing:
At 30 June 2013, the total area under Department of Environment and Conservation's care was 28,531,987 ha.
The department's key responsibilities also included roles in managing, regulating and assessing aspects of the use of the state's natural resources and biodiversity, including the regulation of native vegetation clearing and pollution control. The department initiated 14 environmental prosecutions during 2012–13, involving a broad range of charges including pollution, unauthorised clearing of native vegetation and illegal dumping. At 30 June 2013, eight environmental prosecutions remained before the courts. There were an additional 18 pending cases that, subject to the evidentiary standard being met, could result in prosecution or other sanction.
DEC was also responsible for the wildlife conservation project Western Shield.
The department was also in charge of wildfire prevention and suppression on its land as well as fire prevention in unallocated Crown land.
The indicative burn target for 2012–13 in the south-west forest regions was 200,000 hectares. In 2012–13, DEC achieved 23,468 hectares in the south-west forest regions, including about 6,410 hectares that were burnt for pine plantation protection.
The combination of unsuitable weather conditions, fuels remaining dry due to summer conditions extending into autumn, and enhanced requirements in prescribed burn planning and risk management as a result of the 2011 Margaret River bushfire contributed to a significant reduction of the area able to be prescribed burnt this year.
The average area of burning achieved over the past 10 years has been about 163,019 hectares per annum.
A further 6,023,884 hectares was burnt in the Kimberley, Pilbara, Goldfields, Midwest, Wheatbelt and South Coast regions. The burns were carried out on DEC-managed lands as well as on unallocated Crown lands and unmanaged reserves within these regions.
DEC staff attended and monitored 676 bushfires throughout the state in 2012–13, which burnt about 5,477,394 hectares. The causes of these fires were:
Some of the most severe bushfires the department had to suppress, in chronological order, included:
(1 ha ≈ 2.5 acres)
|Date||Human fatalities||Livestock death/Properties damaged|
|Dwellingup bushfire||Western Australia||12,000 ha||4 February 2007||0||16|
|Boorabbin National Park bushfire||Western Australia||40,000 ha||30 December 2007||3||Powerlines and Great Eastern Highway, forced to close for 2 weeks|
|Toodyay bushfire||Western Australia||3,000+ ha||29 December 2009||0||38|
|Lake Clifton bushfire||Western Australia||2,000+ ha||11 January 2011||0||10 homes destroyed|
|Roleystone Kelmscott bushfire||Western Australia||1,500+ ha||6–8 February 2011||0||72 homes destroyed, 32 damaged, Buckingham Bridge on Brookton Highway collapsed and closed for 3 weeks whilst a temporary bridge was constructed and opened a month after the fires|
|Margaret River bushfire||Western Australia||4,000 ha||24 November 2011||0||34 homes destroyed including the historic Wallcliffe House |
|Carnarvon bushfire complex||Western Australia||800,000+ ha||27 December 2011 - 3 February 2012||0||11 pastoral stations (fences, watering systems, water points, stock feed).|
|Black Cat Creek bushfire ||Western Australia||1,300 ha||12 October 2012||1 (DEC firefighter Wendy Bearfoot)||Private lands, pine plantations, Two Peoples Bay Nature Reserve.|
National parks (and the earlier forms) in Western Australia were under: 
The department maintained and coordinated a range of specialist equipment and emergency response vehicles. This included pumpers, water bombers and tankers and other equipment relating to operations involving search and rescue and firefighting.
The Department of Water and Environmental Regulation was established by the Government of Western Australia on 1 July 2017. It is a result of the amalgamation of the Department of Environment Regulation, Department of Water and the Office of the Environmental Protection Authority.