Question: What is a cave diving organisation which was formed in September 1973 that administers and supports cave diving activity in other parts of Australia including the Nullarbor Plain and  a town in inland New South Wales, Australia, located at the junction of the Macquarie and Bell Rivers?

Context paragraphs:
Southern hairy-nosed wombat: The southern hairy-nosed wombat ("Lasiorhinus latifrons") is one of three extant species of wombats.  It is found in scattered areas of semiarid scrub and mallee from the eastern Nullarbor Plain to the New South Wales border area.  It is the smallest of all three wombat species.  The young often do not survive dry seasons.  It is the state animal of South Australia.

Fowlers Bay, South Australia: Fowlers Bay, formerly Yalata, is a small coastal town in the Australian state of South Australia located about 658 km north-west of the state capital, Adelaide.  Situated on the Nullarbor Plain, it was once an active port and a gateway to the western reaches of the continent, but fell into decline in the 1960s.  At the 2006 census, Fowlers Bay and the surrounding area had a population of 125.

Mitchell, Australian Capital Territory: Mitchell (postcode: 2911) is a light-industrial estate of Canberra, Australia in the district of Gungahlin.  Mitchell was named in honour of Major Sir Thomas Livingstone Mitchell, an explorer of inland New South Wales and Surveyor-General of New South Wales.  The streets in Mitchell are named after Australian industrialists.

Wellington, New South Wales: Wellington is a town in inland New South Wales, Australia, located at the junction of the Macquarie and Bell Rivers.  It is within the local government area of Dubbo Regional Council.  The town is 362 km from Sydney on the Great Western Highway and Mitchell Highway.

Waterfall Way: The Waterfall Way is a road in New South Wales, Australia.  It runs east-west from the Pacific Highway to the New England Highway at Armidale.  The route passes through some of New South Wales' most scenic countryside and has become well known as New South Wales best and Australia's third most beautiful tourist drive.  Seven national parks, of which three are listed as World Heritage Areas by UNESCO and form part of the Gondwana Rainforests of Australia (formerly the Central Eastern Rainforest Reserves), are located on or close to the route.  Dorrigo National Park encompasses the waterfalls that give the route its name.  It also provides one of the few road links between coastal and inland New South Wales, and is therefore more heavily trafficked than its condition might otherwise suggest.

Murrawijinie Cave: Marrawijinie Cave is cave located in the Australian state of South Australia within the gazetted locality of Nullarbor on the Nullarbor Plain.

Warrumbungles: The Warrumbungles are a mountain range in the Orana region of New South Wales, Australia.  The nearest town is Coonabarabran.  The area is easiest accessed from the Newell Highway which is the major road link directly between Melbourne, Victoria and Brisbane, Queensland and cuts across inland New South Wales from the north to the south.

Cave Divers Association of Australia: The Cave Divers Association of Australia (CDAA) is a cave diving organisation which was formed in September 1973 to represent the interests of recreational scuba divers who dive in water‐filled caves and sinkholes principally in the Lower South East (now called the Limestone Coast) of South Australia (SA) and secondly in other parts of Australia.  Its formation occurred after a series of diving fatalities in waterfilled caves and sinkholes in the Mount Gambier region between 1969 and 1973 and in parallel to a South Australian Government inquiry into these deaths.  The CDAA’s major achievement has been the dramatic reduction of fatalities via the introduction of a site rating scheme and an associated testing system which was brought in during the mid-1970s.  While its major area of operation is in the Limestone Coast region of SA, it administers and supports cave diving activity in other parts of Australia including the Nullarbor Plain and Wellington, New South Wales.

Mark Tedeschi: Mark Alfred Guido Tedeschi, AM, QC (born 1952) is an Australian barrister, law professor, photographer and author.  He has won numerous awards for his photography and has been featured in galleries throughout the world including in the State Library of New South Wales, the New South Wales Art Gallery, the Center for Fine Art Photography in Colorado, and the National Library in Canberra.  He is the Senior Crown Prosecutor for New South Wales and the Head of Chambers of the 84 Crown Prosecutors.  He is the founder and president of the Australian Association of Crown Prosecutors and a visiting professor at the University of Wollongong.  As a prosecutor, Tedeschi is best known for the prosecution of numerous high-profile cases in Australia including the 2006 conviction of Dr. Suman Sood for illegal abortion and the Backpacker Murders committed by Ivan Milat in the 1990s.

Koonalda Cave: Koonalda Cave is a cave located in Nullarbor Plain within South Australia which is notable as an archeological site.

Supporting paragraphs: Cave Divers Association of Australia Wellington, New South Wales
Answer: Cave Divers Association of Australia