The NSW Water Administration Ministerial Corporation (WAMC) has a collective 32,027 megalitres (ML) of water savings or Adaptive Environmental Water (AEW) allocations. Since 1999 to present, the MWWG has been providing advice to the WAMC on how best to manage the allocations for environmental purposes. The actual management of the AEW allocations is also conducted by the MWWG on behalf of the WAMC, on a trial basis.

The AEW allocations have been generated through two different sources:

• 30,000 ML was generated through seepage control works within Murray Irrigation Limited that were funded by the NSW Government; and
• 2,027 ML was generated through hydrologic rehabilitation works on Moira Lake, Moira State Forest, NSW. See the Moira Lake Rehabilitation Project webpage for more information.

  The primary objective for managing the AEW allocations is to achieve the optimum environmental benefit. Each year this is achieved by either:

  1. diverting water to target wetlands requiring increased inundations; or
  2. temporarily trading up to 50% of the water savings to fund further wetland rehabilitation work, and diverting the remaining water into wetlands.

The proportions of the AEW allocations diverted to wetlands and/or traded varies from year to year and is dependent on river flow conditions and specific conditions at possible target wetlands.

The MWWG aims to use as much water as possible by diverting into target wetlands throughout the Murray Valley. However when conditions are dry, such as what has been experienced from 2001 to 2004, it has been difficult to deliver the environmental water to the wetlands. The appropriateness of watering wetlands (majority of which are naturally temporal systems i.e. adapted to both a wet and dry phase) in dry conditions must also be taken into consideration.

Normally, up to 50% of the 30,000 ML allocation may be traded on the temporary transfer market within the Murray Catchment over three years. For the 2,027 ML up to 50% of the allocation can be traded annually. In years when conditions are too dry to deliver water to most wetlands, trading of the water is a preferred option.

The AEW allocations are stored within Hume Dam and have a special 'environmental' category. Being stored in Hume Dam therefore restricts the diversions of the water to the River Murray floodplain.

Diverting Water to Target Wetlands:

Environmental conditions within the Murray Region determine the use of the AEW allocations for wetlands. The use of the AEW allocations is restricted to natural wetlands on NSW-side of the River Murray floodplain from Hume Dam to the South Australian border.

In flood years, water can be piggy-backed on to floods to extend natural flood events. This can advantage bird breeding events (if water levels drop before chicks have fledged the nest, the adults will abandon the nests) or help vegetation complete its reproductive cycle. During drier years, however, there is limited opportunity to "lift" water onto floodplains via floods.

The options for using the 32,027 ML are also limited by the need for appropriate infrastructure for delivery and flow levels.

One approach used by the Group to overcome the delivery limitation is to use irrigation infrastructure to enable delivery of environmental water allocations to isolated wetlands on private properties. See Wetlands on Private Properties.

Temporary Trading of the AEW Allocation:

• Up to 50% of the 30,000 ML can be traded over three years via the temporary transfer market within the Murray Catchment.
• Up to 50% of the 2,027ML can be traded annually via the temporary transfer market within the Murray Catchment.

Funds generated from the sale of a portion of the AEW allocations are used for rehabilitation projects to achieve best environmental outcomes. Funds are used for the following type of projects and on-ground works;

• provision of funds for the MWWG Wetland Incentive Scheme and the MWWG Wetland Rehabilitation and Investigations Program. Both funding schemes are available to private and public landholders interested in improving/rehabilitating wetlands;
• installation of regulators or fishways;
• installation of fencing, piezometers, revegetation works, small-scale earthworks etc. aimed at improving wetland management;
• commissioning of technical assessments to assess the degradation risk and future management options for specific wetlands;
• development of wetland management plans;
• focused research and field trials to assess and refine the wetland management requirements;
• provision of alternative water supply to landholders adversely affected by wetland rehabilitation activities; and
• future management of the AEW allocation and associated costs.

Management of AEW Allocation 2000 to 2006:

Year 2006 - a total of 1,966 ML was available from only one Adaptive Environmental Water allocation. Total volume diverted = 426 ML, Total volume traded = 0 ML, Total volume carried over = 1,164.9 ML:

Due to the continuation and increasing severity of the drought across the Murray Darling Basin, adaptive environmental water was only available from one allocation (a regulated river (high security), max. volume = 2,027 ML) currently managed by the MWWG. At the beginning of the water season the total available from this allocation was 1,966.2 ML. However as the season progressed the available volume decreased. No water was available from the second allocation (regulated river (conveyance), max. volume = 30,000 ML).

As a consequence of the limited volumes available for use, the majority of environmental watering projects were suspended for the 2006-2007 season. A small total of 426 ML was diverted into three wetlands within the Lower Murray Darling catchment. A total of 1,164.9 ML water was allowed to be carried over into the 2007-2008 water season.
 

• 288 ML was diverted into two wetlands (wetland A = 48 ML, wetland B = 240 ML) located on private properties in south-west NSW. Both wetlands are natural riverine depressions located on the Murray River floodplain. Environmental water was pumped into the wetlands during September – October 2006.
   

  For wetland A this was its first artificial watering event. A total of 3 ha (out of 7 ha) were inundated. The wetland remained wet for 10-11 weeks. A good vegetation response was recorded, including regeneration of River Red Gums and Old Man Saltbush (Atriplex nummularia).
   

  For wetland B, this was its second artificial watering event. A total of 240 ML (an additional 70 ML compared to the first watering event) was pumped into the 15 ha wetland. With the extra water provided the wetland stayed wet for up to 5 months. Native aquatic plant species, which were not present during the first watering event, were recorded during the second watering. Presence of the aquatic species is possibly a consequence of the increase in flooding duration and depths achieved.
   

  Wetland A — at 5 weeks post-flooding, November 2006

  Wetland B — 18 weeks post-flooding, January 2007.

• 138 ML was diverted into Thegoa Lagoon, Wentworth, NSW. Due to the severity of the drought and limited water availability the watering event was cancelled at the request of the Water Administration Ministerial Corporation.

Year 2005 - a total of 24,911 ML was available from the Adaptive Environmental Water allocations and included 351 ML of donated water. Total volume diverted = 10,415ML, Total volume traded = 14,268 ML:

• 3,181 ML used in the Wetlands on Private Properties Project. Water was diverted into 25 private wetlands (total 597 ha) from September to November within the Murray Irrigation Ltd. Area of Operation. Monitoring included vegetation, birds and photopoints. The projects were aimed at providing drought relief to stressed vegetation.
   

  For the first time three private wetlands (totalling 27 ha) in the Lower Murray Darling region (i.e. along the Murray downstream of Euston to the Sth. Australian border) had water pumped into them. All projects were aimed at providing drought relief to stressed vegetation, especially River Red Gums. Monitoring included vegetation, water quality and photopoints. For two of the wetlands water was pumped into them during September 2005. For the third private wetland due to approval delays, water was not delivered until March 2006. This wetland stayed wet for a longer period of time (approx 40 weeks) and vegetation response, especially fringing River Red Gums, was not as positive compared to spring-time watering events.
   

• 7069 ML was diverted into Wanganella Swamp, inundating 234 ha. Wanganella is located 30 km north of Deniliquin, NSW on the Cobb Highway and is part of the Forest Creek system, which receives water from the Murray and Murrumbidgee Rivers. Wanganella Swamp is a known major breeding area for various species of Ibis and other waterbirds and also provides other important ecological and social benefits including improved water quality, flood mitigation, opportunities for scientific research, recreation, education and aesthetic values. Vegetation monitoring recorded 37 species (81% native & 19% introduced) of aquatic and semi-aquatic plants present from November 2005 to February 2006. Native species Giant Rush (Juncus ingens) and cumbungi (Typha orientalis) were used for nesting material by breeding ibis. Up to 55 bird species were recorded at the swamp (Nov to Feb 2006), including two migratory species, Latham’s Snipe and Sharp-tailed Sandpipers, and two vulnerably listed species the Brolga and Australasian Bittern.

Wanganella Swamp - Open water area with rushes/sedges in foreground, 2005-2006

Wanganella Swamp - Straw-necked Ibis chick approximately 3 week old, 2005-2006.

• 150 ML was diverted into Thegoa Lagoon, Wentworth, NSW. The environmental allocation was combined with 1,015 ML of supplementary water also diverted into the wetland from September to December. Water quality monitoring showed all parameters were within, or close to, recommended levels for the protection of freshwater ecosystems. A good vegetation response was recorded with the majority of species recorded being native. Control of Noogoora Burr (Xanthium occidentale) infestations remains a challenge to managers.

Thegoa Lagoon – photopoint monitoring shows succession of vegetation communities before, during, after flooding (from Left) 25 Nov 05, 21 Nov 05, and 30 March 2006.

Year 2004 - a total of 22,210 ML was available from the Adaptive Environmental Water allocations. Total volume diverted = 17,795 ML, Total volume traded = 5,298 ML:

• 5,220 ML used in the Wetlands on Private Properties Project. Water was diverted into 32 private wetlands (total 997 ha) from September to November within the Murray Irrigation Ltd. Area of Operation, 3 private wetlands (32 ha) Moira Private Irrigation District and 2 private wetlands (140 ha) West Corurgan irrigation district. This was the first time that the project had been expanded into other irrigation districts to help improve private property wetlands. Monitoring incorporated vegetation, birds and photopoints.

Wetlands on Private Property Project 2004-2005 - A drumstick (Craspedia globosa) dominated wetland. One of the new areas participating in the project within the West Corurgan area, NSW.

• 835 ML was diverted into Pollack Swamp, near Barham, during October to November inundating 120 ha of wetland area. The flooding of the swamp follows on from the 2003 environmental watering event. The project was aimed to maximise on vegetation improvements initiated by the 2003 event, suppress sapling distribution from the centre of the Pollack Swamp back to the margins of the wetland and improve aquatic and semi-aquatic flora species regeneration. Monitoring incorporated vegetation, birds and photopoints.

Pollack Swamp - Flooded areas used by Australian White and Straw-Necked Ibis for feeding in 2004.

• 440 ML was diverted into Boomanoomana State Forest wetlands, between Yarrawonga and Barooga from October to November. Up to 72 ha of the swamp were inundated during the project. The project aimed to establish how much water is required to provide an environmental flow to the wetlands, help to restore a flood cycle to the wetland, improve conditions for vegetation health and encourage aquatic and semi-aquatic flora species regeneration. Monitoring incorporated vegetation, birds and photopoints. Brolgas were observed feeding in the wetland.

Boomanoomana Swamp – Area of open water created by the 2004 environmental watering event.

• 8,800 ML was diverted into the Gulpa Creek wetlands, located on the western side of the Moira State Forest during September to October. The wetlands have a high environmental value due to the large nesting colonies of waterbirds and support a diverse range of wetland vegetation communities including Giant Rush (Juncus ingens), Moira Grass (Pseudoraphis spinescens) and Tall Spike Rush (Eleocharis sphacelate). Monitoring incorporated vegetation, birds and photopoints.
• 1,500 ML was transferred to the South Australian Government for environmental use in Chowilla Floodplain wetlands, South Australia. In conjunction with the Lindsay-Walpolla system in Victoria, the Chowilla Floodplain is one of the six Significant Ecological Assets under the Living Murray initiative. The environmental water was pumped into a number of wetlands to relieve drought stress to hundreds of River Red Gum trees from November to January. Monitoring incorporated vegetation, groundwater, sap flow, water heights and rates and photopoints.

Woolshed Creek, Chowilla Floodplain, SA – one of the sites which received Adaptive Environmental Water from NSW in 2004.

• · 1,000 ML, donated to the ABC Radio National’s Bush Telegraph “Water Challenge”, was used to assist flows through the Barmah-Millewa Forest complex and specifically through the Gulpa Creek wetland system. The previous year’s unique radio challenge asked listeners to become an environmental flow manager and decide the best use of 1,000ML. The on-line voting resulted in the water being diverted into the Barmah-Millewa Forest complex at a suitable time. That suitable time was September 2004 with the water diverted into the wetlands along Gulpa Creek. The Gulpa Creek wetlands, particularly the two largest areas - Reed Beds Swamp and Coppinger's/Duck Lagoon, have high environmental value, principally for their large nesting colonies of waterbirds. The associated River Red Gum forest is important habitat for many terrestrial and semi-aquatic plant and animal species and helps support the local timber and tourist industries. The creek itself has notable habitat value for native fish. Bush Telegraph's 1000 ML Helps Creek Wetlands - Dec 2004 Newsletter Bush Telegraph's 1000 ML Helps Creek Wetlands - Dec 2004 Newsletter

Year 2003 - Total volume diverted = 7,800 ML, Total volume traded = 11,600 ML:

• 4,700 ML was used in the Wetlands on Private Properties Project. Water was diverted into 49 wetlands from September to November resulting in a significant increase in wetland vegetation diversity & abundance and increase in bird numbers.
• 1,600 ML was diverted into the Gulpa Creek wetland complex, NSW from October 2003 to January 2004. The AEW allocation helped to extend a natural flow which facilitated a bird breeding event eg: ibis, egrets and ducks and was also helpful to allow vegetation to complete its reproductive cycle.

Gulpa Creek Wetlands - successful ibis breeding event and vegetation response, 2003.

• 950 ML was diverted for 39 days during October to November into Pollacks Swamp, north of Barham, NSW. Pollacks Swamp is a Flora Reserve and known nesting area for Intermediate and Great Egrets. Less regular flooding of the swamp has seen it change from an open woodland environment to a dense sapling thicket. The increase in the number of saplings will have a negative impact on the breeding behaviour of the egrets. The AEW allocation inundated approximately 118 ha of the Swamp.

Pollacks Swamp - the flooding has encouraged an abundance of semi-aquatic grasses and forbs to
grow around the swamp margin and improved the health of the River Red Gums. (Photo courtesy of Paul Childs)

• 550 ML was diverted into Thegoa Lagoon, Wentworth, NSW. The environmental allocation supplemented surplus flows that were allowed into the wetland from August to December. The combination of flows have resulted in a good wetland vegetation response, over 83 bird species recorded, and helped in the prevention of saline groundwater intruding into the wetland.

Thegoa Lagoon, Wentworth - Refilling of lagoon in September 2003 (top left), good vegetation response January 2004 (right & bottom left).

Year 2002 - Total volume diverted = 3,085 ML, Total volume traded = 20,910 ML:

• This year was an extremely dry year, and therefore areas in which water could be diverted were extremely limited.
• 3,085 ML was used in the Wetlands on Private Properties Project. Water was diverted into 43 wetlands from October to November resulting in a significant increase in wetland vegetation diversity & abundance and increase in bird numbers.

Wetland area on property near Deniliquin. Week 0 - before receiving environmental water (left) and Week 6 - after watering (right).

Wetland area on property near Deniliquin. Week 0 - before receiving environmental water (left) and Week 16 - after watering (right).

	Wetland area on property near Moulamein. Week 0 - before receiving environmental water (top left), Week 9 (right) and Week 16 - after watering (bottom left).

Wetland area on property near Moulamein. Week 0 - before receiving environmental water (left) and Week 6 - after watering (right).

Year 2001 - Total volume diverted = 4,570 ML, Total volume traded = 15,000 ML:

• 4,000 ML diverted into Werai Forest, NSW during November. Water was used to water a remnant stand of Common Reeds (Phragmites australis) and to also determine flooding paths and commence-to-flow levels within the forest. The latter information will be used for the development of environmental flow rules for the forest.

  Flooding of the Werai Forest in 2001.

• 570 ML was used in the first trial year of the Wetlands on Private Properties Project. Eleven wetlands on 10 private properties within the Murray Irrigation Limited Area of Operation received environmental water during October - November. Irrigation infrastructure was used to deliver to the water to the wetlands. These wetlands no longer receive natural floodwaters and/or rainfall run-off due to development of surrounding land, installation of roads, levee banks etc. The time period for which the wetlands had last received water varied greatly from 2 years up to 40 years. Key findings included:
  • Increased abundance in wetland plants such as reeds (Juncus spp.), rushes (Eleocharis spp.), nardoo (Marsilea spp.) etc.;
  • Regeneration of wetland plants from the existing seed bank, including water ribbons (Triglochin spp.), starfruit (Damasonium minus), and water milfoil (Myriophyllum spp.);
  • Black box trees (Eucalyptus largiflorens) at all sites exhibited signs of new growth, and some flowered; and
  • Improved landholder knowledge and understanding of wetlands and the benefits of delivering water to these formerly dry sites.

Bungoonah Swamp - a private property wetland near Jerilderie that received environmental water, 2001.

A wetland on private property near Tullakool. Week 0 - before receiving environmental water (left) and Week 15 - after watering (right).

Year 2000 - Total volume diverted = 32,027 ML, Total volume traded = 0 ML:

• 30,411 ML diverted into the Barmah-Millewa Forests. The AEW allocation helped extend a natural flooding event. By prolonging the duration of the flood, approximately 30,000 wetland birds bred in the wetlands and forests. Breeding bird species included brown bitterns, egrets, swans, nankeen night herons, comorants and ibis. Some of the species had not been seen in the area for up to 30 years.
• At the end of the flood event, a Carp Harvest was conducted in Moira Lake. Specially designed nets were used which enabled a commercial fisher to harvest approximately 60 tonnes of carp that were travelling out of the Lake and heading back into the Murray River. The nets have been designed so that native fish are not caught.

  Australian white ibis - one of the species that bred in the thousands during the flooding of the Barmah-Millewa Forests, 2000.
  Photographs courtesy David Leslie.

• 1,500 ML diverted into Wanganella Swamp (north of Deniliquin), NSW. The water helped thousands of ibis (straw-necked, Australian white and glossy), and royal spoonbills successfully breed.

Wanganella Swamp - successful breeding event for ibis and royal spoonbills. Photograph courtesy Damian Green