Murbpook Wetland Rehabilitation

Duration:    September 2005 to present        

Partners:

SA MDB NRM Board

Surrounding landholder

Residents of Ridgeway Estate (estate which is directly across the River Murray)

Overview:

A general description of the wetland is:

• Permanent unmanaged (Hydrologically) lagoon.
• Lagoon surface area of 113.6 ha with a management area of 280 ha.
• Relatively shallow for the majority of the surface area.
• Lagoon has a permanent connection to the River Murray to the south at Lock 1 pool level and an elevated temporary connection to the northeast.

Murbpook Lagoon was a site surveyed as part of the 2004 Wetland baseline Survey, a RMCWMB project.  Results are highlighted below:

          Water Quality – Data collected on:

• Salinity/Conductivity – EC (µS/cm),
• Dissolved Oxygen (mg/L),
• pH
• Turbidity (NTU)
• and Temperature (°C)

          Groundwater

• Groundwater monitoring network of four wells established 
• Groundwater elevation @ 29/01/04 ranged from 2.5m to 2.63m AHD compared to the River pool level of 3.25m AHD. 
• Lagoon represents a topographic and hydraulic depression, converging groundwater flow gradients from the River and from the high land to the west towards the lagoon. 
• Lagoon pool level data was not available but predicted to be 2m AHD, indicating the connectivity to the River was restricted. 
• Groundwater salinity in the four wells ranged from 7000 µS/cm to 35000 µS/cm @ 29/01/04.  Freshest groundwater was encountered in wells ML3 and ML1, the most saline groundwater occurred in well ML4. 
• Subsequent monitoring on 01/06/04 showed an increase in salinity in all wells but the relative spatial distribution remained the similar. 
• The similarities of moderately high salinities in the lagoon and the groundwater indicate a degree of connection between the two (groundwater intrusion). 
• Higher groundwater salinities to the north where the groundwater was relatively deep may be a result of inflowing regional groundwater. 

Macroinvertebrates

• Total of 580 macroinvertebrates from 15 taxa were recorded during November 2003 (540) and March 2004 (40) indicating moderate diversity.
• Samples collected were dominated by Corixids (water boatmen) which are synonymous in still or slow moving fresh water and have high pollution tolerance.
• A Stream Invertebrate Grade Number Average Level (SIGNAL) scores for November and March were calculated at 2.92 and 3.14 respectively.  This indicates severe water quality pollution which could be attributed to high EC or nutrient enrichment.

Frogs

• Five species recorded:  Common Eastern Froglet; Eastern Sign-bearing Froglet; Spotted Grass Frog; Person’s Tree Frog; and Southern Bell Frog.  Records taken in November 2003 and February, March and September 2004.
• Southern Bell Frog is considered vulnerable and is protected under the Federal EPBC Act and the state National Parks and Wildlife Act.  Locally common frog lives in woodland, shrubland, grassland and disturbed areas.

Birds

• 20 species of water birds were recorded with 610 individuals observed.
• The Grey Teal was the most abundant species with 344 individuals.  Other identified species included the Silver Gull (69 individuals), Black-winged Stilt (44 individuals) and the Australian Pelican (40 individuals).
• One species of state significance, the Australasian Shoveler, and 13 species protected under the EPBC Act were recorded.
• Overall abundance and diversity of wetland birds was well above average when compared to other wetlands surveyed.
• “The shallow, saline, temporary nature of the water body and the lack of high quality floodplain vegetation may have been responsible for the absence of other species of wetland birds.”

Fish

• 526 fish from four species, two native and two introduced, were recorded.  Native carp gudgeon dominated the catch (398 individuals), followed by the introduced gambusia (96 individuals) and carp (25 individuals), and native bony bream (7 individuals).
• The presence of juvenile and adult carp suggests that carp may be breeding within the wetland.

Vegetation

• No submerged or floating aquatic vegetation recorded.
• Two shrubland species of conservation significance were recorded, Callistemon brachyandrus (prickly bottlebrush) and Eragrostis lacunaria (purple love-grass).
• The Eucalyptus largiflorens (river box) recorded were in good to excellent health.
• Control of introduced species and stock grazing will promote the spread of native ground layer species and support the conservation of Callistemon brachyandrus and Eragrostis lacunaria.
• The lack of variation in water levels has constricted the fringing vegetation to a narrow, patchy band of reeds and sedges.  Changes in water regimes will increase the area of littoral zone and provide more diverse habitat for fauna.

The management recommendations of the Baseline Survey were to:

• Introduce a wetting and drying cycle.
• Monitor vegetation, in particular the fringing and submerged vegetation.
• Monitor fish to assess the impact of carp on native populations.
• Monitor water quality, in particular salinity concentrations in surface water.

Designs were drafted by Ken Smith Technical Services in August 2005 to install two regulating structures, one at the secondary inlet creek entrance and one mid way along the length of the creek.  Once a management plan has been developed for the sit (early 2006) the structures will be installed in late 2006.

A community group that incorporates residents from both sides of the River (although in its infancy stages of development) will assist with the progression of all elements of the project.  An inception monitoring event and group meeting will be held on 4^th December 2005.

Ramco Lagoon Wetland Rehabilitation Project

Duration:             1996 until present

Partners:

Ramco Wetland Management Group

Central Irrigation Trust (CIT)

Golden Heights Irrigation Trust (GHIT)

Loxton Waikerie District Council

Waikerie Apex

SA MDB NRM Board

SA Water

Overview:

Ramco Wetland is located 5km north-wet of Waikerie and is 11.7km upstream of Lock 2.  At normal pool level (approximately 6.4m) the wetland covers approximately 93.1ha.  The total area of the floodplain and wetland is approximately 190ha.  Ramco wetland is a large lagoon with a narrow permanent downstream inlet/outlet and a temporary upstream channel.

Ramco Wetland in its current state is a highly degraded system with little habitat value and limited biodiversity.  The impacts of river regulation (permanent inundation) and the use of the wetland as a disposal basin have contributed to the wetlands current state.

Four flow barriers as well as reed blockages exist on the wetland.  The downstream inlet at the river junction is partially blocked by willows.  In the past these trees have become so dense that they have severely restricted water flow into the channel.  Two causeways along the downstream inlet, one half way along the inlet, consisting of three 0.8m pipes set half way into the water, and another near the wetland junction that consists of one half blocked 0.3m pipe, regulate flows into the wetland.  A causeway consisting of two box culverts across the upstream channel regulates flows through this channel.  This was installed to avoid the wetland flushing at pool level and therefore releasing salt without adequate dilution.

A number of threatening (both potential and real) processes to the wetland have been identified.  These threats take the form of biological, such as weed infestations; physical, such as salinisation of the wetland; and management related issues such as killing long-lived vegetation through poorly executed management actions.  Identifying threats to the wetland is an important component in informing wetland managers of problems and ensuring management actions themselves do not pose a threat to wetland rehabilitation.

The Goon Squad, as they are commonly known, came into existence in March 2003 and consists of a diverse cross section of the local community.  The group has 17 members, nine of which actively participate in on-ground works whilst the remainder receives the group’s minutes.  The group has partnerships, of varying strengths, with SA Water, Central Irrigation Trust, Golden Heights Irrigation Trust, Sunlands Irrigation Trust, South Australian Murray-Darling Basin Natural Resources Management Board, Riverland West Local Action Planning Association, Loxton Waikerie District Council and the Ramco Community Association.

To date the group has procured significant outcomes for the wetland, some of which are:

• Two public meetings regarding the management of the wetland were held and attended by representatives from DWLBC, SA Water, EPA, RWLAP and local residents.
• Funding from the Department of Water, Land Biodiversity and Conservation has been obtained for the development of a management plan for the wetland.
• The wetland was included in the River Murray Wetlands Baseline Survey conducted by environmental consultants Sinclair Knight Merz for the River Murray Catchment Water Board, Local Action Planning groups and the Department of Water Land and Biodiversity Conservation.  The baseline data obtained from this survey was utilized in the development wetland management plan.
• Site visits to the wetland by Mike Stephenson, the Environmental Health Officer for the District Council of Loxton Waikerie, were arranged to highlight the degradation occurring unnecessarily.
• Midge and mosquito control works were initiated in conjunction with the District Council of Loxton Waikerie.
• Negotiations commenced with Central Irrigation Trust and Golden Heights Irrigation Trust regarding the disposal of irrigation drainage water into the wetland.  Agreements were reached and a community grant ($10,000) from the South Australian Murray-Darling Basin Natural Resources Management Board obtained to complete the diversion of drainage water from the wetland into the Salt Interception Scheme.
• A quarterly monitoring schedule was designed and committed to by the group as part of the development of the wetland management plan.  Parameters being regularly monitored include groundwater, surface water, vegetation health, and fish.
• The ‘Flicking of the Switch’ ceremony formally highlighted the commencement of irrigation drainage water diversion from the lagoon; the event was launched by Minister Karlene Maywald.
• Willow removal at inlet/outlet creed increased flow into the creek and lagoon.
• A community grant ($80,000) was obtained from South Australian Murray-Darling Basin Natural Resources Management Board for the installation of a regulating structure.  This structure will finally enable the group to hydrologically manage the wetland.

Ramco Lagoon Wetland Management Plan – Summary

In March 2003 a public meeting was called by local residents regarding problems associated with the wetland which were severely impacting on their quality of life.  This meeting raised the long-standing issues of intense rotten egg smells emanating from the wetland, significant midge and mosquito populations and poor appearance.  The ecological and aesthetic values of the wetland are currently very poor, illustrating the severely degraded nature of the area.  It was noted that the degradation afflicting the wetland, particularly through salt build up, also poses a risk to the water quality of the River Murray.  These problems can only be addressed through consistent management actions.  The Ramco Wetland management plan establishes clear community and scientifically derived management objectives to further improve the biological and physical health of the wetland complex.

Vision Statement

To improve the health of existing red gums around Ramco Wetland and establish new red gum communities, to improve the diversity and abundance of native birds and to minimise areas around the wetland displaying salt scald.  The wetland will also emit little to no hydrogen sulphide and midge populations will be at a tolerable level by community standards.

Mission Statement

To manage Ramco Wetland to reduce salinity levels and to encourage native vegetation to thrive and support a diversity of bird species for the benefit of the local community.

Objectives

The short-term objectives (5-10 years) for the management for Ramco Wetland are:

• To manage the wetland so as to minimise as much as possible the smell released from the lagoon,
• To reduce the area of suitable habitat for midges and mosquitoes to breed by removing drainage water and distributing hormone growth control,
• To improve the health of existing red gum and black box communities through an appropriate management regime,
• To encourage native vegetation to grow in areas currently affected by salt build up, and
• To increase the abundance and diversity of native birds on Ramco Wetland.

The overall long-term objectives (15-20 years) for the wetland are to:

• Ensure the long term protection of the riverine environment,
• Improve the health, diversity, and habitat value of existing riparian and terrestrial vegetation, in particular red gum and black box,
• Establish new red gum and black box communities,
• Improve water quality, and therefore aquatic habitat within the wetland,
• Eradicate or control noxious weeds and exotic plants,
• Control pest animals,
• Encourage responsible public use and enjoyment of the wetland and surrounding areas, and
• Improve the quality of life for surrounding residents.

The Future Management objectives for the wetland will be guided by an adaptive management approach (‘learning by doing’).  The objectives may change as the health of the wetland begins to improve and new issues are created.

Future On-ground Works

Future on-ground works at the site will primarily focus on installing the regulating structure and implementing the Wetland Management Plan.

Brenda Park Scotts Creek Wetland