Cumbung Swamp

The Cumbung Swamp is a reed swamp, located at the junction of the Murrumbidgee and termination site of the Lachlan Rivers and covers some 15,000 to 20,000 ha (37,000 to 49,000 acres) at full capacity, and about 14,000 ha (35,000 acres) out of flood. The swamp is in South West New South Wales within the Riverine district and its closest township is Balranald.

The swamp is composed of wetland reed beds as well as extensive River Red Gum Woodland areas, some of the largest in the Murray Darling Basin.[1] January 2019 saw the purchase of 33,000 hectares including and surrounding the swamp by a private group composed of The Nature Conservancy (TNC) and Tiverton Agriculture, to ensure the protection and sustainability of the area.[1]

The Great Cumbung Swamp is recognised nationally as a highly significant ecosystem. This has seen it placed on both the Directory of Important Wetlands in Australia as well as the now-defunct Register of the National Estate, ensuring its significance is recognised and thus protected.[2] This significance is mainly due to the Cumbung Swamp being one of the largest remaining reed swamps in Eastern Australia as well as its inclusion of unique River Red Gum forest biomes, which are an at-risk ecosystem.

Pre-European occupation of the Cumbung Swamp area, in the Riverina District dates back over 40000 years, with the presence of several Aboriginal groups residing in the area. This includes the Nari-Nari, to the East, Yida-Yida and Mudi-Mudi, to the North, and Gurendji peoples, all of whom made use of the abundant resources surrounding the two rivers. The major group in the Cumbung area, however, was the Wiradjuri people, which translates to people of three rivers. These rivers were the Macquarie, Lachlan, and Murrumbidgee, with the later of the two forming the southern boundary of the group, at the location of the Cumbung Swamp System.

The extensive river systems in the Riverine district allowed for a range of resources to be utilised by the lands first peoples, from hunting for fish in the rivers to the gathering of fruits as well as use of raw materials for shelter and recreational use, evidence of which can be seen through the many scar trees located along both the Lachlan and Murrumbidgee Rivers.[11]

The feeling of connection to the area, particularly the Murrumbidgee River, is captured through the poetry of Iris Clayton, who explores the decline in the river’s health, as well as the need for conservation to protect the area, including the Cumbung Swamp.

'No one knows how long he's been there
Twisted, old ravaged beyond repair
Father to many, too many to count.
His dying will be a terrible account
Perhaps if the damage is quickly mended
His shores and banks strongly defended
Old River Bidgee need never be
Another lost legend of the Warrajarree.’

— Iris Clayton (1988)[12]

Through the purchase of the properties surrounding and including the Cumbung Swamp, by the TNC and Tiverton Agriculture (see Protection and Conservation) a partnership has been established with the closely located Nari Nari Tribal Council to ensure the cultural inclusion of the Nari Nari people and protection of the area, one which chairman Ian Woods states, the Nari Nari “people are very supportive of the Great Cumbung purchase and we look forward to working with TNC and Tiverton on plans for its future management.”[1]

The Cumbung Swamp has been identified as a significant wetland both in the Lower Lachlan Catchment as well as in the wider Murray Darling Basin, seeing it placed on the Directory of Important Wetlands.[2] In 1980, it was listed in the now-defunct Register of the National Estate.[13]

It is therefore evident that the swamp and surrounding areas are important and therefore must be managed. This has not been the case in the past, with the site being managed as agricultural land for the past generations, with the first notable levees being constructed in the mid-1800s.[2]

The area has most recently been run as two adjoining cattle enterprises, with this intensive use of the land leading to a significant decrease in groundwater storage, through the growth of water-dependent pastures. The running of the land for livestock has also seen the clearing of portions of the River Red Gum forests for access as well as some compaction of the soils.

However, these properties, Juanbung and Boyong, totalling 33,765 acres, with almost 20,000 making up the Great Cumbung Swamp, were purchased in January 2019 for $55 million.[14] The buyers were Australian company Tiverton Agriculture in conjunction with The Nature Conservancy, whose primary aim was to stop the area from being negatively impacted by the implementation of irrigation schemes, therefore attempting to continue to preserve and regenerate the natural flows of the catchment. Since the purchase, TNC, managed by Tiverton Agriculture has developed further aims to continue running it as an agricultural property, further emphasising how both conservation and profitability can co-exist. Other land uses identified for the area include “carbon, biodiversity offsets and stewardship, and ecotourism”[1] all of which further the value of the wetland. The total land area now protected in the area now amounts to over 200,000 hectares, with properties owned by the Government and private corporations, such as TNC, as well as areas of National Park adjacent to the Cumbung Swamp.[15]

These plans, however, must be managed in conjunction with the greater catchments water plans, with the allocated Environmental Water Flows particularly impacting upon the water available to the swamp. Through monitoring of the Lachlan Rivers flow, from as far upstream as Wyangula Dam, the impact river regulation has on the extent and health of the swamp can be assessed. In 2010 the NSW Department of Environment, Climate Change and Water concluded that if 700GL/day were delivered, as measured at the upstream Boogil Weir, limited reed bed flooding would occur, however, 3,000 GL/day would be required to cause extensive flooding of the swamp.[4]

This is further analysed through the Lachlan Rivers Environmental Flow plans, whereby 24,000ML of Commonwealth Water was allocated to the Swamp in the year 2015-2016. This ‘environmental watering’ was provided with the aim to contribute to “ecosystem functions such as nutrient cycling, support vegetation condition and the ability of the ecosystem to withstand drought and flood”,[16] therefore, protect and sustain the area.

Through the careful monitoring and assessment of the Cumbung Swamp and overall Lachlan and Murrumbidgee catchments, particularly through the allocation of water, the area can be carefully managed to ensure its survival as an important Australian Wetland.