Sweeney's Lagoon Wmp 2006 Large

Sweeney’s Lagoon MANAGEMENT PLAN 2006

LAPS Lower Murray Local Action Planning Groups Kjartan Tumi Bjornsson

This management plan was written by Kjartan Tumi Bjornsson for the Mid Murray Local Action Planning Association Inc., and reviewed and endorsed by the SA River Murray Wetland Technical Group. Funding was provided by the National Action Plan for Salinity and Water Quality, the Natural Heritage Trust, and the River Murray Catchment Water Management Board. The management plan has been prepared according to the Guidelines for developing wetland management plans for the River Murray in South Australia 2003 (RMCWMB and DWLBC 2003) and as such fulfils obligations under the Water Allocation Plan for the River Murray Prescribed Watercourse. Disclaimer: The Mid Murray Local Action Planning Association Inc. do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaim all liability for any error, loss or other consequences, which may arise from you relying on any information in this publication. Cite as: Bjornsson, K. T. (2006). Sweeney’s Lagoon Management Plan. Mid Murray Local Action Planning Association Inc., Murray Bridge. Acknowledgements: This wetland management plan has been developed with the support of a number of organisations, community groups, and individuals. Special thanks go to Wayne Bryce for his efforts Adrienne Frears and for assistance with the draft. Thanks also go to those that contributed their knowledge including the South Australian Murray Darling Basin Natural Resources Management Board and the members of the South Australian River Murray Wetland Technical Group. For further details contact: Mid Murray LAP PO Box 10 Cambrai, SA 5353 Phone: (08) 8564 6044 Fax: (08) 8564 5003 Photographs: Cover photographs: Top, Sweeney’s Lagoon and watered river red gums (TB) Bottom, Sweeney’s Lagoon open water section (TB) Photographs in document (TB) Tumi Bjornsson; (AF) by Adrienne Frears © Mid Murray Local Action Plan 2006

Swan Reach & Districts Landcare Group c/- 15 Arthur Street, Tranmere SA 5073 Phone (08) 8332-1929 Email [email protected]

20th March 2006

To Whom It May Concern, The Swan Reach and Districts Landcare Group would like to confirm our involvement with the Sweeney’s Lagoon Wetland Management Plan. Our group was very keen to have close involvement to firstly ensure the Baseline survey was completed then have the management plan written. Our group previously received funding from the then NHT 1 & 2 funding periods to construct and replace six water management flow paths under the name of the Moorundie Wetland complex. Of these, two were constructed at Sweeney’s Lagoon These sites were purposely built to provide water manipulation options together with carp control gates. The goal is to ensure the lagoon is maintained at his current ecological health and then to demonstrate to the local community ways to improve the overall health of the lagoon and surrounding floodplains. In summary the group is happy to submit the Management Plan and understands its contents, together with applying for a long-term water licence. If you require further information, please do not hesitate to contact.

Wayne Brice Chairman, Swan Reach Landcare Group

Sweeney’s Lagoon Management Plan 2006

TABLE OF CONTENTS TABLE OF CONTENTS ................................................................................................................... i LIST OF FIGURES...................................................................................................................... ii LIST OF MAPS ........................................................................................................................... ii LIST OF TABLES ........................................................................................................................ ii Chapter 1.

INTRODUCTION ..................................................................................................... 4

1.1

Environmental, Social and Cultural Significance of wetland ............................................. 4

1.2

Why does Sweeney’s Lagoon need a management plan?............................................... 4

(a)

Mission Statement ....................................................................................................... 5

(b)

Vision Statement ......................................................................................................... 5

(c)

Broad Objectives ......................................................................................................... 5

(d)

Current Achievements ................................................................................................. 5

Chapter 2.

SITE DESCRIPTION OF SWEENEY’S LAGOON .................................................... 7

2.1

Wetland Location and Description ................................................................................... 7

2.2

Survey Sites, Dates & Locations...................................................................................... 8

2.3

Physical Features ............................................................................................................ 8

(a)

Sweeney’s Lagoon in Current State ............................................................................. 8

(b)

Geomorphology, Geology And Soils .......................................................................... 11

(c)

Climate ...................................................................................................................... 12

(d)

Wetland Volumes and Water Requirements for Various Filling Stages ...................... 12

(e)

Surface and Groundwater Features ........................................................................... 13

2.4

Ecological Features ....................................................................................................... 20

(a)

Flora .......................................................................................................................... 20

(b)

Fauna ........................................................................................................................ 21

2.5

Implications for Management ......................................................................................... 23

Chapter 3.

SOCIAL ECONOMIC AND CULTURAL VALUES .................................................. 26

Chapter 4.

LAND TENURE, JURISDICTION AND MANAGEMENT ARRANGEMENTS ......... 27

Chapter 5.

THREATS AND POTENTIAL SOLUTIONS TO SWEENEY’S LAGOON ................ 29

Chapter 6.

MANAGEMENT OBJECTIVES .............................................................................. 32

Chapter 7.

IMPLEMENTATION OF PLAN ............................................................................... 35

7.1

ON GROUND ACTION AND TIMETABLE ..................................................................... 35

7.2

WETLAND WATER OPERATIONAL PLAN ................................................................... 37

(a)

Water regime ............................................................................................................. 37

(b)

Volume calculations ................................................................................................... 37

Chapter 8.

MONITORING ....................................................................................................... 40

Chapter 9.

EVALUATION, REVIEW AND REPORTING .......................................................... 42

9.1

Evaluation and Review .................................................................................................. 42

9.2

Reporting ....................................................................................................................... 42

REFERENCES ............................................................................................................................. 43 i

Sweeney’s Lagoon Management Plan 2006 (a)

Flora of Sweeney’s Lagoon ....................................................................................... 52

(b)

Birds .......................................................................................................................... 57

(c)

Fish ........................................................................................................................... 58

(d)

Macroinvertebrates .................................................................................................... 60

LIST OF FIGURES Figure 1: Pumping in progress (AF) ................................................................................................ 6 Figure 2: Inlet looking to river (WB) ................................................................................................. 6 Figure 3: Middle causeway (WB) .................................................................................................... 6 Figure 4: Rear basing at far end of wetland (WB)............................................................................ 6 Figure 5: Sweeney’s main lagoon 28/07/06 (TB) ........................................................................... 10 Figure 6: Sweeney’s Lagoon dry red gums 28/07/06 (TB)............................................................. 10 Figure 7: Sweeney’s main lagoon and lignum 28/07/06 (TB) ........................................................ 10 Figure 8: Sweeney’s azolla and lignum 28/07/06 (TB) .................................................................. 10 Figure 9: Sweeney’s main lagoon 28/07/06 (TB) ........................................................................... 10 Figure 10: Sweeney’s Lagoon main structure 28/07/06 (TB) ......................................................... 11 Figure 11: Sweeney’s connecting creek 28/07/06 (TB) ................................................................. 11 Figure 12: Hydrogeology of the Moorundi Wetland Complex (Barnett 1989) ................................. 12 Figure 13: Median River Levels below Lock 1 ............................................................................... 14 Figure 14: Water regime ............................................................................................................... 37

LIST OF MAPS Map 1: Sweeney’s Lagoon location ................................................................................................. 7 Map 2: Wetland Levels.................................................................................................................... 9 Map 3: Historical channels (Map courtesy of Wayne Bryce) .......................................................... 15 Map 4: Structures.......................................................................................................................... 16 Map 5: FIM III flow volumes that connect the wetland to the river ................................................. 17 Map 6: Cadastral boundaries covering Sweeney’s Lagoon and surrounds.................................... 27

LIST OF TABLES Table 1: Baseline survey monitoring parameters and dates ............................................................ 8 Table 2: Summary of wetland volumes within Sweeney’s Lagoon................................................. 13 Table 3: Structures........................................................................................................................ 13 Table 4: Median River Levels below Lock 1 .................................................................................. 14 Table 5: Water quality Sweeney’s Lagoon .................................................................................... 18 Table 6: Groundwater monitoring locations ................................................................................... 18 Table 7: Groundwater monitoring results ...................................................................................... 19 Table 8: Tree health Eucalyptus camaldulensis ............................................................................ 20 ii

Sweeney’s Lagoon Management Plan 2006 Table 9: Most significant habitat use at Sweeney’s Lagoon .......................................................... 21 Table 10: Frogs recorded at Sweeney’s Lagoon ........................................................................... 22 Table 11: Sweeney’s Lagoon responsible positions contact details .............................................. 28 Table 12: Existing and potential threats to Sweeney’s Lagoon ...................................................... 30 Table 13: Management objectives for Sweeney’s Lagoon............................................................. 33 Table 14: Implementation plan for Sweeney’s Lagoon .................................................................. 36 Table 15: Water required over fill period of Sweeney’s Lagoon ..................................................... 38 Table 16: Calculated water loss (evaporation – precipitation) ....................................................... 38 Table 17: Water use calculation .................................................................................................... 38 Table 18: Monitoring plan for Sweeney’s Lagoon. ......................................................................... 41 Table 19: Wetland Atlas Data ....................................................................................................... 45 Table 20: Plant Associations at Sweeney’s Lagoon ...................................................................... 52 Table 21: Ongoing vegetation surveys .......................................................................................... 54 Table 22: Habitat features identified in Sweeney’s Lagoon ........................................................... 57 Table 23: Bird species observed at Sweeney’s Lagoon ................................................................ 57 Table 24: Habitat use by waterbird species at Sweeney’s Lagoon ................................................ 58 Table 25: Fish survey sites ........................................................................................................... 58 Table 26: Fish captured at Sweeney’s Lagoon.............................................................................. 59 Table 27: Habitat at sample location ............................................................................................. 60 Table 28: Macroinvertebrates captured at Sweeney’s Lagoon ...................................................... 60

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Sweeney’s Lagoon Management Plan 2006

Chapter 1.

INTRODUCTION

Since the adoption of the Water Allocation Plan for the River Murray in 2002, the wetlands of South Australia have an annual water allocation of 200GL. To access this water allocation for wetland management, a licence is now required. Sweeney’s Lagoon is listed in Appendix A of the Water Allocation Plan for the River Murray (RMCWMB 2002) and has therefore a right to access to the 200GL. This wetland management plan is structured in accordance with the criteria set out in the Guidelines for developing wetland management plans for the River Murray in South Australia (RMCWMB and DWLBC 2003).

1.1

ENVIRONMENTAL, SOCIAL AND CULTURAL SIGNIFICANCE OF WETLAND

The Wetland Atlas of the South Australian Murray Valley (Jensen et al. 1996) listed Sweeney’s Lagoon (wetland name used in Wetland Atlas is Blanchetown Flat) as having a high-moderate conservation value and to be of basin and local importance (see Appendix A on page 45). As part of the Management of Wetlands of the River Murray Valley Draft Action Plan 1996-1999 (South Australian River Murray Wetlands Management Committee (SARMWMC) 1996), Portee complex was listed as having a high priority (first in the High rankings) for maintenance or rehabilitation. The Floodplain Wetlands Management Strategy (Murray-Darling Ministerial Council 1998) lists the Portee Creek wetlands as a large and significant floodplain wetland complex in the Murray Darling Basin. With minimal effort, the maintenance and improvement of a healthy wetland environment can be expected at this site. This management would be a significant achievement for wetland management in the region. Management including the maintenance of the ephemeral nature of the wetland, weed control, and feral animal control are expected to deliver a large return for a minimal investment. Based on the past efforts, the significance and uniqueness of the wetland management of Sweeney’s Lagoon is a high priority. A short timeline of management at Sweeney’s Lagoon (some data from local anecdotal evidence): 1841 Area settled including irrigation development (see Moorundi Wetland Complex Management Plan 2002 (Jensen and Turner 2002)) 1986 Included in Thompson’s report (Thompson 1986) 1999 Included in Wetland Management Study (Jensen et al. 1999) 2002 Wetland Management Plan (Jensen and Turner 2002) 2002 Installation of two culverts, with carp screens and sluice gates at the culvert connecting the wetland to the River Murray 2004-2005 included in River Murray Wetlands Baseline Survey (SKM 2006b) 2006 January river red gum rescue watering trial Ongoing water quality monitoring by community members Ongoing tree health monitoring by community members &SAMDB NRM Board staff

1.2

WHY DOES SWEENEY’S LAGOON NEED A MANAGEMENT PLAN?

A plan for the management of the entire Moorundi wetland complex was developed in 2002 for the Mid Murray Local Action Planning Association by Wetland Care Australia (Jensen and Turner 2002). This plan did not comply with the Guidelines for developing wetland management plans for the River Murray in South Australia (RMCWMB and DWLBC 2003). However, following onground works initiated as part of this early plan a potential exists to manage some of the water regime of the wetland and the exclusion of carp through carp screens. Based on assessment of 4

Sweeney’s Lagoon Management Plan 2006

recently available data from the baseline survey The River Murray Wetlands Baseline Survey - 2005 (SKM 2006b), as well as ongoing monitoring, historic data and anecdotal information, a better management strategy for the wetland is possible, which will address the current ecological constraints on the wetland. (a) MISSION STATEMENT The rehabilitation of Sweeney’s Lagoon is aimed at maintaining and improving wetland ecological values, such as maintaining habitat for the benefit of frogs, fish and waterbirds and the improvement of vegetation such as preserving the health of river red gums and lignum. (b) VISION STATEMENT The vision for Sweeney’s Lagoon is a healthy clear water temporary wetland fulfilling a diversity of habitat requirements for native fauna. It is envisaged that the wetland will maintain its diversity of macrophytes providing habitat for native fish and birds. The fish barriers will be improved (reduced) based on the most recent research. The wetland will have regular visits by water birds, including migratory species. The riparian area will be maintained in its current condition of mostly local native species, both through active involvement with the removal of weed species and through the watering of river red gums. The current land management will remain contributing to the maintenance of the vegetation diversity. (c) BROAD OBJECTIVES The broad objectives of the wetland restoration include: Reduce fish barriers Maintain ephemeral nature of wetland Maintain current ecological heath of wetland Monitor the impact of hydrology regime for adaptive management and avoidance of potential salinisation threat (d) CURRENT ACHIEVEMENTS A plan for the management of the entire Moorundi wetland complex was developed in 2002 for the Mid Murray Local Action Planning Association by Wetland Care Australia (Jensen and Turner 2002). Due to this plan, box culverts were constructed to replace the inadequate pipe culverts. Sweeney’s was part of the floodplain watering project run by DWLBC, where 136 ML were pumped onto the wetland and allowed to dry by evaporation, some water was already present due to above entitlement flows (Rover 2006). The pumping commenced on the 12th of January 2006. The wetland was filled reaching a level of 1.9 m AHD. Figure 1 through to Figure 4 show the wetland during pumping and 8 days later. As can be seen in Figure 3 the wetland was filled to capacity with the water almost reaching to the top of the culvert, the top of the culvert is at approximately 2 m AHD. The rear basin seen in Figure 4 reportedly reached a depth of 1 m. A gauge board was not installed until the 6th of April at which time the water level was still sitting at 1.23 m AHD whereas by 1st September the level was down to 0.76 m AHD (Frears 2006).

5

Sweeney’s Lagoon Management Plan 2006

Figure 1: Pumping in progress (AF)

Figure 2: Inlet looking to river (WB)

Figure 3: Middle causeway (WB)

Figure 4: Rear basing at far end of wetland (WB)

6

Sweeney’s Lagoon Management Plan 2006

Chapter 2. 2.1

SITE DESCRIPTION OF SWEENEY’S LAGOON

WETLAND LOCATION AND DESCRIPTION

Sweeney’s Lagoon is found in the Hundred of Skurray and listed as being part of Portee Complex with the wetland number S0100 in the Wetlands Atlas (Jensen et al. 1996) and numbered M066 by Thompson (1986). The wetland is located adjacent to Blanchetown (Map 1) between river marker 271 & 273 km. AMG coordinates 482885 E 6231080 N (Grid Zone 54). Sweeney’s Lagoon can be found on the 1:50,000 Blanchetown map sheet number 6829-3. The wetland was classified with a moderate-high conservation value with recommendations to avoid disturbance by regulating further shack development (Thompson 1986). See Appendix A for more information. The wetland covers an area of approximately 14.6 ha. There is a main wetland lagoon and a separate lagoon. There are a number of lentic channels, which present potential connections to the river, most of which need high river levels to connect the two. The main connection to the river is however through the only remaining creek, which is located in the south east of the main lagoon (downstream end).

Map 1: Sweeney’s Lagoon location

7

Sweeney’s Lagoon Management Plan 2006

2.2

SURVEY SITES, DATES & LOCATIONS

The River Murray Wetlands Baseline Survey - 2005 (SKM 2006b) monitored different wetland parameters (Table 1). The locations of the baseline survey sites can be seen in Appendix B. Table 1: Baseline survey monitoring parameters and dates Parameter

Date 1 (BLS)

Date 2 (BLS)

Date 3 (BLS)

Date 4 (BLS)

Date other

See page

Site physical

N/A

7

Vegetation

2005

20

Fish

Autumn

Spring

22

Birds

13/04/05 1pm

21/10/05 12:30pm

21

Frogs

24/05/05

31/08/05

Macroinvertebrates

18/10/05

23

Water Quality

18/10/05

13

Groundwater

26/05/05

2.3

11/08/05

02/11/05

25/10/05

21

30/11/05

18

PHYSICAL FEATURES

(a) SWEENEY’S LAGOON IN CURRENT STATE Map 2 shows the two separate sections of Sweeney’s Lagoon. The main section referred to as main lagoon is the only one that can be managed based on the current river flow volumes. Floodplain/river red gum rescue pumping will still be required to inundate the full extent of the wetland.

8

Sweeney’s Lagoon Management Plan 2006

Map 2: Wetland Levels

9

Sweeney’s Lagoon Management Plan 2006

Figure 5 through to Figure 11 show the wetland in its current state with some inundation and healthy growing azolla and lignum as well as recently watered red gums. Figure 6 shows both live and dead red gums, which provide habitat for a number of species.

Figure 5: Sweeney’s main lagoon 28/07/06 (TB)

Figure 6: Sweeney’s Lagoon dry red gums 28/07/06 (TB)

Figure 7: Sweeney’s main lagoon and lignum 28/07/06 (TB)

Figure 8: Sweeney’s azolla and lignum 28/07/06 (TB)

Figure 9: Sweeney’s main lagoon 28/07/06 (TB)

10

Sweeney’s Lagoon Management Plan 2006

Figure 10: Sweeney’s Lagoon main structure 28/07/06 (TB)

Figure 11: Sweeney’s connecting creek 28/07/06 (TB)

The structure installed following a Wetland Care Australia management brief, which included flow control, and fish grills to exclude carp. Other structures have been in stalled to in crease the potential flow through the complex during high river flows. For the most part these connections remain dormant, however the size of the culverts has increased the capability of management to allow large volumes of water to flow trough the complex when high river levels allow. The current management planning of this wetland considers the use of these structures for the best possible management approach, fulfilling the most desirable ecological benefits without causing significant environmental detriment. For this purpose past surveys including the recent baseline survey are discussed in the following chapters. (b) GEOMORPHOLOGY, GEOLOGY AND SOILS The wetland is sitting on alluvial/fluvial sediments from the Holocene. The bore profiles show the geology to consist of mainly dark brown clay characteristic of the Coonabidgal Formation with one bore intersecting the Monoman Formation (AWE 2006), a diagram is presented in Figure 12 (adapted from Smitt, Jolly et al. (2003)). For a detailed account for all bore profiles, refer to the baseline survey data.

11

Sweeney’s Lagoon Management Plan 2006

Figure 12: Hydrogeology of the Moorundi Wetland Complex (Barnett 1989)

(c)

CLIMATE

The following climatic conditions are taken from the Bureau of Meteorology (BOM) Waikerie station (number 024018) (Latitude (deg S): -34.1778; Longitude (deg E): 139.9806) (BOM 2005). The recording of data commenced at Waikerie in 1896; the latest records used in the assessment of the climatic condition of the area stemming from 2001. The area has Mediterranean climatic conditions with warm dry summers and cool wet winters. The median (5th decile) annual rainfall is 249 mm. The mean monthly maximum rainfall is in October (26.2 mm), the minimum in March (12.5). The expected mean daily maximum temperature is highest in January at 33 C, lowest in July at 16.5 C, and has an annual mean of 23.5 C. The minimum daily temperature is at its maximum in January at 15.2 C, and its minimum in July at 5.2 C. The annual mean daily minimum temperature is 9.5 C. (d) WETLAND VOLUMES AND WATER REQUIREMENTS FOR VARIOUS FILLING STAGES A DEM was developed for this area by the baseline survey (see Appendix C). Table 2 summarises the wetland water volumes for Sweeney’s Lagoon. Despite a large part of the main lagoon being at or below the level of the river, the wetland connection at 0.854 m AHD can retard water exchange. Getting water flow into this wetland therefore only occurs when river levels reach above 0.854 m AHD. The water requirement, including evaporative loss, is covered in 7.2.

12

Sweeney’s Lagoon Management Plan 2006 Table 2: Summary of wetland volumes within Sweeney’s Lagoon Area (ha)

Area (m2)

Depth m

RLm (AHD)*

Volume m3 (KL)

Volume ML

Observed river level

0.13

1259.6

0.18

0.61

1623.7

1.6

Full

14.8

147649.6

1.47

1.90

77281.1

77.3

Three quarters full

5.1

50666.8

1.10

1.53

68731.4

68.7

Half full

3.9

38947.7

0.73

1.16

41453.2

41.5

Quarter full

1.9

19,201

0.36

0.79

23244.3

23.2

10 cm depth

0.002

22.8

0.10

0.53

31.1

0.03

Filling Stage

Wetland basin invert 0.43 m AHD Source: Adapted from River Murray Wetlands Baseline Survey - 2005 (SKM 2006c) Base of wetland is to the most par at ~ 0.3 m AHD with the deepest point at -0.45.

(e) SURFACE AND GROUNDWATER FEATURES Surface water The main structure that connects the wetland with the River Murray has an invert at 0.854 m AHD, see Table 3. For the structure to allow water into the wetland, the river levels would need to exceed this level. The median water level in the river immediately downstream of Lock 1 fluctuates rapidly depending on wind direction and flow over Lock 1. As can be seen in Figure 13 and Table 4 the river level exceeds the annual median levels of 1.09 m AHD (0.81 in the past 10 years) regularly. Based on the long-term median river levels Sweeney’s lagoon, with the current invert at 0.854 m AHD, would have been a permanent wetland with a drawdown in autumn. This would have been a longer drawdown in the past 10 years, based on the median water levels. In the very dry past 5 years Sweeney’s Lagoon could still be operated as a temporary wetland filling over the summer months. Other structures have also been constructed to regulate flows through lentic channels, see Map 3, which have the potential of connecting the wetland and the river at high flows. Information on these structures can be seen in Table 3 and their locations in Map 4. Table 3: Structures Structure Type

Description

Diameter (m)

Easting

Northing

Regulator/culvert Invert RL (m AHD)

Crest invert RL (m AHD)

Regulator/culvert length (m)

Southern Outlet Main channel

2 X Box Culverts

1.2 x 1.2

373624.55

6195759

0.854

2.958

5

Pipe under Levee / Road on creek connection to wet land.

1 X Box Culvert

1.2 x 1.2

373322.93

6195808.9

0.705

2.708

8

Pipe under access road on creek.

1X Reinforced Concrete Pipe

1.050

372957.56

6197524.1

3.139

5.35

6

Pipe under access road on creek.

1X Reinforced Concrete Pipe

1.050

373033.6

6197419.8

3.435

5.2

5.5

Pipe under access road on creek.

1X Reinforced Concrete Pipe

0.90r

373127.58

6197342.9

3.076

5.2

7.2

Culvert not included in Baseline survey Source: Adapted from River Murray Wetlands Baseline Survey – 2005 (SKM 2006b)

13

Sweeney’s Lagoon Management Plan 2006 2.50

m AHD

2.00 1.50 1.00 0.50

be r

be r

De ce m

No ve m

O ct ob er

be r

t

Se pt em

Au gu s

Ju ly

Ju ne

ay M

Ap ril

ar ch M

Fe br ua ry

Ja nu a

ry

0.00

Month Monthly Median 1921-2006

Monthly Median 1996-2006

Monthly Median 2001-2006

Figure 13: Median River Levels below Lock 1 Table 4: Median River Levels below Lock 1

January February March April May June July August September October November December Annual

Monthly Median 19212006 0.94 0.86 0.82 0.85 0.88 1.04 1.18 1.68 2.03 2.03 1.86 1.32 1.09

Monthly Median 19962006 0.81 0.76 0.7 0.69 0.71 0.71 0.76 0.8 0.94 0.97 0.97 0.9 0.81

Monthly Median 20012006 0.78 0.74 0.66 0.56 0.52 0.61 0.72 0.78 0.87 0.9 0.87 0.85 0.75

14

Sweeney’s Lagoon Management Plan 2006

Creek 1

Creek 2 Creek 3 Creek 4

Map 3: Historical channels (Map courtesy of Wayne Bryce)

15

Sweeney’s Lagoon Management Plan 2006

Map 4: Structures

The river flood volumes as simulated in the Flood Inundation Model III can be seen in Map 5. The Flood Inundation Model III was used to study the potential critical flow volumes of the River Murray for Sweeney’s Lagoon. Map 5 shows that at a flow level of 27 GL/day the wetland will fill. With a flow level of 57 GL/day, connection will establish between the wetland lagoons and extend through the floodplain to other wetlands. At 77 GL/day, the golf course between the wetland and Blanchetown will start to flood. As can be seen in Map 4 the wetland has had more connection to the river, many of these old connections still remain and have their own flow control structures. 16

Sweeney’s Lagoon Management Plan 2006

These channels may connect with the wetland at high river levels, which may not be picked up with the course FIM model.

Map 5: FIM III flow volumes that connect the wetland to the river

Water was found in the wetland only following high river levels in the final stage of monitoring during the baseline survey, the river having risen above the flow threshold more than a month prior to the monitoring date. The monitored water quality for the wetland can be seen in Table 5, which is adapted from the baseline survey report (MDFRC 2006), this table includes a summary of the river water levels in the month prior to monitoring. The salinity of the wetland ranged from a minimum of 603 EC to a maximum of 790 EC, the median being 720. In comparison, the monitored River Murray salinity obtained from the, DWLBC Surface Water Archive at Lock 1 (DWLBC 2006), which was 302 μS/cm (up stream of Lock 1). The maximum wetland recordings were furthest from the regulator/inlet with the minimum near the regulator. These values were all below trigger levels established for lowland rivers, lakes, reservoirs, and wetlands (DWLBC 2006). The dissolved oxygen (DO) concentrations were not seen to be of concern to management of the wetland (MDFRC 2006). The high DO recorded during one sampling even was attributed to the photosynthetic activity in a region of the wetland where there were abundant filamentous and benthic algae. The maximum pH was recorded in the terminal basin of the wetland reaching 9.12 and was attributed to high levels of primary production. The majority of the pH levels were within the ANZECC (2000) trigger levels for lowland rivers (MDFRC 2006), pH is therefore not a concern for management. The turbidity measurements of the wetland were exceptionally low with a mean of 8 NTU (6-12 NTU’s) this could be related to the ephemeral nature of the wetland and the high number of macrophytes. Turbidity is therefore not a concern for management at this wetland. For a description of the implications of water quality in wetlands refer to Your Wetland: Supporting Information (Tucker et al. 2002). Other water quality parameters monitored, nitrogen, phosphorus, and dissolved organic carbon were not considered a significant management issue. With only a single monitoring event the high levels of nitrogen and phosphorus were assumed to be as a consequence of a ‘nutrient-pulse’ following a dry period or the abundance of zooplankton (MDFRC 2006).

17

Sweeney’s Lagoon Management Plan 2006 Table 5: Water quality Sweeney’s Lagoon Parameters EC wetland μS/cm

Stage 4 19/10/05

720 ± 42

Min.

Stage 4 19/10/05 Mean

9±9

603

Min.

9

Max.

790

Max.

9

EC Lock 1 Upstream* μS/cm

Reading

302

Mean

1138 ± 433

DO mg/L-1

Mean

10.0 ± 1.1

Min.

705

Min.

6.9

Max.

1570

Max.

12.1

Mean

128 ± 73 55

pH

Mean

Parameters

Total N μgN/L

FRP μgP/L

8.44 ± 0.35

Min.

Min.

7.47

Max.

200

Max.

9.12

Mean

230 ± 120

Mean

8±1

Min.

110

Min.

6

Max.

350

Max.

12

Mean

12.85 ± 4.45

Mean

21.0 ± 0.4

Min.

8.40

Min.

20.2

Max.

17.30

Max.

21.7

River height at Lock 1 Downstream *

Reading

1.00

River height at Lock 1 Downstream **

Mean

0.93

Min.

0.84

Max.

1.14

Turbidity NTU

Water Temperature C

Mean

NOx μgN/L

n (baseline survey)

Total P μgP/L

DOC mgC/L

4

2

Source: Adapted from River Murray Wetlands Baseline Survey – 2005 (MDFRC 2006); * from DWLBC Surface Water Archive (Lock 1) (DWLBC 2006); ** Calculated for the month prior to the monitoring date Refer to 0 for the locations of the baseline survey monitoring sites.

Groundwater The baseline survey installed four new groundwater wells within Sweeney’s Lagoon. These wells were monitored 4 times during the survey period; see Table 1 (26th May, 11th August, 25th October, and 30th November 2005). One more 1 site existed at Sweeney’s Lagoon, which was included in the monitoring schedule on the 11th August, 25th October and 30th November 2005 (AWE 2006). The locations of the wells are presented in Table 6 and a map of the groundwater flow direction in Appendix D. Table 6: Groundwater monitoring locations Name

Easting

Northing

Elevation of Bore Hole casing (m-AHD)

Ground Elevation (m-AHD)

SWE R-01

373,481

6,195,912

4.302

3.387

SWE R-02

373,214

6,196,067

2.419

1.624

SWE R-03

373,769

6,196,678

5.66

4.82

SWE R-04

373,208

6,196,658

2.918

1.969

Bla 1802

373,432

6,196,774

4.13

Wetland marker SWES1 Wetland marker SWES2 Source: River Murray Wetlands Baseline Survey – 2005 (AWE 2006)

18

Sweeney’s Lagoon Management Plan 2006

The groundwater levels were found to be lower than river levels. It can therefore be assumed that due to an evaporative low on the floodplain a flow exists from the river and towards the floodplain, see Appendix D. The groundwater levels seemed to follow the increase in river level and show the same seasonal trend (AWE 2006). The measured depths of the ground water can be seen in Table 7. The groundwater salinity ranged from 5,650 EC to 25,200 EC. The bore salinities are believed to be impacted on by wetland inundation as the salinity monitored reduced following an increase in wetland water levels (AWE 2006). The wetland base is lower that some of the observed groundwater levels, indicating a potential for groundwater induced salinisation through evapoconcentration when the wetland is dry (AWE 2006). Future monitoring is required to confirm the baseline survey findings. More recent groundwater data seems to indicate that groundwater levels are influenced by wetland water levels, therefore when the wetland is dry monitoring indicates groundwater levels are also low. The baseline survey report conclusion that saline groundwater evapoconcentration could occur during draw-down is based on data when little water was in the wetland. More recent data shows that it is more likely that groundwater elevations will simply drop as the wetland water levels drop. The last community surface water quality monitoring in July ‘06 showed a conductivity reading of 1008 EC, still relatively fresh considering the water was pumped in back in Dec ’05 to January ‘06. Further recommendations are summarised in Chapter 2.5. Table 7: Groundwater monitoring results

Name SWE R-01

SWE R-02

SWE R-03

SWE R-04

Bla 1802

Wetland marker SWES1

Wetland marker SWES2

Sampling Date

Groundwater Depth Groundwater Depth Groundwater (mbgl) (mBTOC) elevation (mAHD) Conductivity μS/cm

26/05/05

3.09

4.005

0.297

8,520

11/08/05

2.812

3.727

0.575

7,500

25/10/05

2.622

3.537

0.765

5,650

30/11/05

2.625

3.54

0.762

6,090

26/05/05

1.658

2.453

-0.034

24,900

11/08/05

1.435

2.23

0.189

25,200

25/10/05

0.981

1.776

0.643

20,140

30/11/05

1.023

1.818

0.601

23,350

26/05/05

4.495

5.335

0.325

20,620

11/08/05

4.431

5.271

0.389

24,300

25/10/05

4.354

5.194

0.466

20,350

30/11/05

4.328

5.168

0.492

21,850

26/05/05

1.791

2.74

0.178

19,640

11/08/05

1.546

2.495

0.423

20,440

25/10/05

1.376

2.325

0.593

17,200

30/11/05

1.37

2.319

0.599

20,430

11/08/05

3.872

0.258

12,040

25/10/05

3.72

0.41

10,340

30/11/05

3.723

0.407

11,140

11/08/05

0.68

25/10/05

0.46

30/11/05

0.532

25/10/05

1.05

30/11/05

1.12

Source: River Murray Wetlands Baseline Survey – 2005 (AWE 2006)

19

Sweeney’s Lagoon Management Plan 2006

2.4

ECOLOGICAL FEATURES

(a) FLORA A vegetation survey was conducted by the baseline survey in 2005. The baseline survey identified 34 native species within the survey area and 14 exotics (SARDI Aquatic Sciences 2006b); see Appendix E,. A great diversity of vegetation associations seems to be focused around the southwestern part of the wetland area. The vegetation associations located in this part include Eleocharis acuta (common spike-rush) sedgeland, Myriophyllum verrucosum (red milfoil) submerged herbland and Muehlenbeckia florulenta (lignum) shrubland (SARDI Aquatic Sciences 2006b). The baseline survey monitoring team surveyed six plant associations at Sweeney’s Lagoon (SARDI Aquatic Sciences 2006b). These associations are listed below and their location can be seen in Appendix B. The rare species coccid emubush Eremophila gibbifolia was found in the Chenopodiaceae shrubland association in the Eucalyptus largiflorens (river box) open woodland area (SARDI Aquatic Sciences 2006b). A detailed list of species found within the plant associations can be found in Appendix F. An ongoing vegetation survey has been initiated by the SA MDB NRM Board as part of monitoring of management change within the wetland, including floodplain inundation (pumping) and this management plan. The species recorded in the quadrats of this ongoing survey can also be seen in Appendix F. Further mapping of the listed species Eremophila gibbifolia and Muehlenbeckia horrida throughout the wetland complex is recommended. 1. 2. 3. 4. 5. 6.

Chenopodiaceae shrubland in dry central lagoon Sporobolus mitchellii grassland on dry lagoon bed Chenopodiaceae shrubland in depression on Blanchetown golf course Eleocharis acuta sedgeland on edge of main lagoon Myriophyllum verrucosum submerged herbland in main lagoon Muehlenbeckia florulenta shrubland in main lagoon

River box Eucalyptus largiflorens were, with the exception of three individuals, found to be mainly in excellent or good condition (SARDI Aquatic Sciences 2006b). The river red gum Eucalyptus camadulensis var. camadulensis health was found to be highly variable due to the lack of floods in recent time with only just over 10% in excellent condition (SARDI Aquatic Sciences 2006b). The most stressed red gums were to be found on the upper banks of the lagoon and the surrounding floodplain although the poor red gums were also interspersed with healthier ones (SARDI Aquatic Sciences 2006b). The red gum locations and health score can be seen in Appendix E. Large woody debris (LWD) covered less than 5% of the wetland with most of it in one of the higher flow channels (SARDI Aquatic Sciences 2006b). Since the inundation of the wetland through the pumping project described previously there has been some response by red gums. The response has been largely positive as can be seen in Table 8. Table 8: Tree health Eucalyptus camaldulensis Ranking / Description (Your Wetland method) 1- All epicormic growth, no original canopy 2- <25% of original canopy remaining, many dead branches 3- 25-50% of original canopy present 4- 50-75% of original canopy present 5- >75% of original canopy present- healthy tree TOTAL

Number of Trees Pre-Watering (Oct 2005) 11

Post-Watering (Sept 2006) 5

6 10 11 4 42

8 12 11 6 42

Source: Adrienne Frears SA MDB NRM Board (2006)

20

Sweeney’s Lagoon Management Plan 2006

Weeds known to be present around Sweeney’s Lagoon include Californian burr Xanthium californicum (orientale) and African boxthorn Lycium ferocissimum. Golden dodder Cuscuta campestris a category 1 weed may also be present. Floodplain inundation could have implications with regard to their dispersal. (b) FAUNA Fauna surveys were undertaken as part of the River Murray Wetlands Baseline Survey - 2005 (SKM 2006b). Individual teams with appropriate expertise conducted a number of surveys on fauna in the wetland environment. These surveys are described below. Birds The bird assessment of the baseline survey was located at two sites, one a fixed area search the other a transect (EBS & HydroTas 2006). The surveys were undertaken twice in the baseline survey period, once in autumn and once in spring. Both sites had simple shorelines with patchy low cover, occasional hollow bearing trees and perching trees such as red gums (EBS & HydroTas 2006). One site was dry during the autumn survey the second very shallow. With an increase in water levels the shoreline complexity changed somewhat, see Table 22 in Appendix F. With the water level increase for the second survey the availability of dry mud reduced increasing wet mud and covering some of the low vegetation (EBS & HydroTas 2006). The baseline survey observed 16 waterbird species in the spring survey with 207 individuals. No waterbird species were observed during in autumn although four terrestrial species (9 individuals) were observed during this sampling period. The three most abundant birds observed were the Grey Teal Anas gracilis with 101 individuals, the Australian Pelican Pelicanus conspicillatus with 60 individuals and the Straw Necked Ibis Threskiornis spinicollis with 15 individuals (EBS & HydroTas 2006). Nine species were listed as migratory including the most abundant observed waterbird the grey teal (EBS & HydroTas 2006). The baseline survey observed nine species that were roosting and nine foraging, see Appendix F. The difference in the habitat availability was mainly the increase in wet mud and an increase in water level for the spring survey. The most significant habitat use by birds at the wetland is shown in Table 9, a list with the habitat use of all baseline survey recorded birds at the wetland and the observed activity can be seen in Table 24 in Appendix F. Based on the number of birds the open water is an important habitat, based on the abundance of species utilising a habitat the wet mud and sedges are the most utilised habitats. Table 9: Most significant habitat use at Sweeney’s Lagoon Habitat

Individuals

Number of Species

Open water

72

4

Mud

85

5

Dead logs

33

3

Sedges

8

5

Lignum

8

2

Reed beds

1

1

Frogs A frog survey was included in the baseline survey with three separate monitoring dates, these frog surveys were conducted by SA MDB NRM Board staff (SA MDB NRMB 2006). Four frog species were recorded at Sweeney’s Lagoon during the survey, which are listed in Table 10. No frog species were heard during the May sampling period and all four species were heard during the November sampling period. Of the recorded species the Eastern banjo frog Limnodynastes dumerilii and the spotted grass frog L. tasmaniensis were the most commonly recorded species during this baseline survey, they were 21

Sweeney’s Lagoon Management Plan 2006

also recorded at another 19 wetlands out of the 22 surveyed (SA MDB NRMB 2006). Both of these species are highly adaptable using strategies such as burrowing (L. dumerilii) and being highly mobile and therefore a colonising species (L. tasmaniensis). Of significance is the number of Eastern sign bearing froglets Crinia parinsignifera recorded at this site. This species was otherwise only recorded in the Riverland sites. The habitat associated with this species is water couch Paspalum distichum which was available near site 2 (SA MDB NRMB 2006). The Peron’s tree frog Litoria peroni was the most abundant species recorded during the November sampling period. The habitat associated with this species is mature red gums. Consistent with the finding of the baseline survey is the know calling period between September and January and the preference of this species to breed in temporary pools (SA MDB NRMB 2006). Table 10: Frogs recorded at Sweeney’s Lagoon Date

Site 1 (Inlet channel near river)

Site 2 (Wetland near dense lignum)

Eastern banjo frog

Eastern sign bearing froglet

Peron's tree frog

Spotted grass frog

Eastern sign bearing froglet

Spotted grass frog

Eastern banjo frog

Peron's tree frog

Limnodynastes dumerili

Crinia parisignifera

Litoria peronii

Limnodynastes tasmaniensis

Crinia parisignifera

Limnodynastes tasmaniensis

Limnodynastes dumerili

Litoria peronii

one

few

many

few

few

few

few

many

24/05/05 31/08/05 02/11/05

few

many

many

Abundance: One = 1, Few = 2 - 9, Many = 10 - 50, lots = >50 Source: River Murray Wetlands Baseline Survey – 2005 (SA MDB NRMB 2006)

Fish The baseline survey included a fish survey at Sweeney’s Lagoon by SARDI Aquatic Sciences (2006a), once in autumn and once in spring. Due to a lack of water in the wetland, the autumn survey only focused on two refuge pools in the inlet channel. The species collected are shown in Appendix F. The composition of species caught varied between the seasons although the number of species caught remained the same. Fish mobility due to environmental factors would have contributed to the difference in species and fish abundances (SARDI Aquatic Sciences 2006a). Overall, the native to exotic species ratio was 1.8:1. However, the abundance of exotic fish brings the ratio of the number of native fish to exotic to 3.9:1 (597 native and 152 exotic). Most of the exotics were eastern gambusia Gambusia holbroki with 108 caught in the autumn survey. The most abundant native species were the carp gudgeons with 562 individuals. The dwarf-flathead gudgeon Philypnodon sp. and Murray rainbowfish Melanotaenia fluviatilis were both caught in Sweeney’s Lagoon and both are proposed to be listed as threatened (rare) under the revised National Parks and Wildlife Act 1972 (DEH 2003; SARDI Aquatic Sciences 2006a). The refuge pools could therefore be an important resource for these species and therefore a significant aspect of consideration for wetland management. The concentration of fish in the refuge pools may have skewed the results to indicate only a marginal increase in numbers following wetland inundation. It must however be considered that during the spring sampling the fish would have been more widely dispersed. In all likelihood, more fish were to be found in the wetland during the spring sampling. The number of small fish suggested recent reproduction either within or adjacent to the wetland (SARDI Aquatic Sciences 2006a). Flow control structures can have an impact on the movement of fish in and out of wetland environments, due to changes in water flow (velocities, turbulence) (see Your Wetland: Supporting Information (Tucker et al. 2002)). In the case of Sweeney’s Lagoon the reduction of movement of fish is possibly evidenced by the low abundances of fish despite the good water quality and abundance of food (zooplankton) (SARDI Aquatic Sciences 2006a). 22

Sweeney’s Lagoon Management Plan 2006

Macroinvertebrates The River Murray Wetlands Baseline Survey - 2005 (SKM 2006a) monitored macroinvertebrates at Sweeney’s Lagoon in spring only. A total of 21 distinct taxa with 5,500 individuals were collected (SKM 2006a). The diversity at Sweeney’s Lagoon was seen to be low; the full list of taxa and abundance can be seen in Appendix F. The baseline survey related the low diversity to the ephemeral nature of the wetland. Of the taxa found at the wetland the most abundant ones were either highly mobile or have short life cycles making them prime rapid colonisers. Some pollution sensitive taxa were present, suggesting relatively good water quality in the wetland, although a higher proportion was found close to the connection to the River Murray. The most abundant non-insect taxa were the Planorbidae (order Gastropoda). The species of this family generally require low saline water with submerged macrophytes. The presence of this species would suggest that the salinity issue discussed in the groundwater section may not be an acute problem and may therefore only become a problem following long term dry periods. For a description of the function of macroinvertebrates in wetlands refer to Your Wetland: Supporting Information (Tucker et al. 2002).

2.5

IMPLICATIONS FOR MANAGEMENT

The River Murray Wetlands Baseline Survey - 2005 (SKM 2006b) had a number of recommendations to make for improved management of the wetland. The recommendations were based on each survey team’s assessment of their collected data and have been summarised below. The groundwater survey (AWE 2006) had a number of recommendations for further monitoring in order to verify their findings and guide future management. The minimum recommended groundwater monitoring made by the groundwater team was the continuation of the quarterly frequency. The main concern was the threat posed through evapoconcentration during dry spells being flushed into the river when the wetland became inundated. Therefore, the following recommendations were made by the baseline survey team to improve the data obtained and its applicability to wetland management and to estimate the salinity impact of the wetland management on the river: Intensive monitoring during river level change Permanent river and wetland markers installed Data logger installed to provide a continual record of groundwater levels Install two new piezometers in the centre of the wetland to monitor the recharge from the wetland to the watertable and to monitoring the groundwater salinity to obtain an estimate of the potential salt loads to the river. The methodology of instillation and the monitoring employed for the best use of this strategy is described in detail in the baseline survey document (AWE 2006). The wetland does not show a significant increase in salinity, the evapoconcentration is therefore not as significant an issue as the groundwater team at first hypothesised. New piezometers will therefore not be installed. However, the data logger will provide information to clarify the groundwater flow pattern. One will be used at the wetland if funding can provide for its acquisition. The water quality team found the water at the wetland to be of good quality with the non-nutrient parameters falling within or close to the expected range for this wetland (MDFRC 2006). The water quality is seen as supporting diverse and abundant communities. Therefore, the water quality team had the following recommendations: Maintain the ephemeral nature of the wetland through the wetting and drying cycle Examine the cause of high nutrient levels through regular monitoring of nutrients. 23

Sweeney’s Lagoon Management Plan 2006

The native submergent, emergent, and riparian species were found to be in good condition in the main lagoon and the inlet to the wetland. River box Eucalyptus largiflorens were seen to be in a good condition with a rare listed species present but river red gum Eucalyptus camaldulensis var. camaldulensis were stressed due to a lack of flooding. Based on these findings the recommendations from the vegetation team of the baseline survey (SARDI Aquatic Sciences 2006b) were; Maintenance of current land management practices Address lack of flooding (floodplain pumping project, to water river red gums, was undertaken after the baseline survey vegetation assessment, the response has been positive and should be included in regional management strategies in the future) The recommendation made by the baseline survey bird team (EBS & HydroTas 2006) was; Maintain the ephemeral nature of the wetland through the wetting and drying cycle as the submerged vegetation found currently in the wetland, due to the current management regime, provided a valuable food resource for the waterbird species The ephemeral nature of the wetland has provided a favoured frog breeding habitat and promotes frog calling (SA MDB NRMB 2006). Based on the monitoring results the recommendations from frog team of the baseline survey (SA MDB NRMB 2006) included; Maintain the ephemeral nature of the wetland through the wetting and drying cycle as it has been linked to frog breeding Hold flood waters in wetland for extended periods using flow control structure to prolong the frog breeding period The increasing fringing vegetation (sedges/rushes) to be encouraged as it provides habitat (site 2 grassy area to be maintained as a great abundance of frogs were recorded at this site) Frogs to be monitored two to three times a year at the same sites (assistance from local Wetland Project Officer), link monitoring to the annual South Australian Frog Census in September Frog monitoring to coincide with red gum watering The wetland is seen as a good habitat for small fish species, where ample food is available and good water quality is present with evidence of recent breeding activity. However, some issues exist that can improve the conditions of the wetland for native fish species. The recommendation from the fish team of the baseline survey (SARDI Aquatic Sciences 2006a) therefore are: Improve fish passage. Carp screens, stop logs, and closed-top box culverts all act to deter movement of some small native species. Depending on research, future improvements could include the alteration of the mesh and/or a change to open top culverts. The shallow entrance to the lagoon is also seen as a barrier and should be considered if funding allows. Carp screens to remain as carp were seen attempting to migrate into the wetland. Carp separation case could be considered depending on research results. Secure locking of screens to combat vandalism of operation is required (rocks were used to prop open the carp screens) Deep pools in inlet to be maintained as refuge Invasive species management in refuge pools until carp screens secured No concrete recommendations were made by the macroinvertebrate team (SKM 2006a). However, some significant outcomes that relate to the habitat availability for macroinvertebrates were identified. Based on the information contained in the macroinvertebrate chapter of the baseline survey the following management considerations seem prudent: 24

Sweeney’s Lagoon Management Plan 2006

Salinity does currently not seem to be as great an issue as anticipated by the groundwater team From these recommendations and the data from the baseline survey strategies for the management of the wetland can be made. The following chapters discuss other aspects influencing management including: land tenure, values, and threats. The developed management strategy for the wetland including hydrology regime and monitoring strategy is detailed in the following chapters.

25

Sweeney’s Lagoon Management Plan 2006

Chapter 3.

SOCIAL ECONOMIC AND CULTURAL VALUES

Most wetlands of the River Murray are of cultural value to the local indigenous population. In recognition, aboriginal input is sought on any projects having a significant impact on the River Murray wetlands, such as the construction of sluice gates. Indigenous consultation was obtained for the Wetland Management Plan written in 2000 (Jensen and Turner 2002) for the structures planed for the wetland complex. Sweeney’s Lagoon is adjacent to a number of shacks along the River Murray in Blanchetown. This wetland and its surrounding floodplain would therefore have an inherent value to the local residents and shack owners. A healthy wetland would also be of value to Blanchetown residents due to its proximity to the town.

26

Sweeney’s Lagoon Management Plan 2006

Chapter 4. LAND TENURE, MANAGEMENT ARRANGEMENTS

JURISDICTION

AND

There are multiple properties, which encompass Sweeney’s Lagoon and the surrounding land. The wetland lagoon itself covers three in private ownership. Some of the surrounding properties are residential (shacks) with the town of Blanchetown immediately north of the wetland floodplain. The property boundaries and the key ownership details can be seen in Map 6.

Map 6: Cadastral boundaries covering Sweeney’s Lagoon and surrounds. 27

Sweeney’s Lagoon Management Plan 2006

The Sweeney’s Lagoon community members i.e. the Swan Reach and Districts Landcare group, with support from the Mid Murray LAP and the SA MDB NRM BOARD, will be responsible for the management of the wetland in consultation with the landholders. Contact persons for Sweeney’s Lagoon management will be Mid Murray LAP Officers, Wetland Management Planning Officer or SA MDB NRM BOARD Wetland Project Officer, see Table 11 for contact details. Access to the wetland will need to be arranged through consultation with the relevant landowner, contact with whom should be established through the Mid Murray LAP or Swan Reach and Districts Landcare group. Table 11: Sweeney’s Lagoon responsible positions contact details Position

Present Officers

Organisation

Mailing Address

Phone number

Chairman of the Wayne Brice Swan Reach and Districts Landcare Group

Swan Reach and Districts 15 Arthur Street Landcare Group

Tranmere

SA 5073

(08) 8332 1929 0409 102 814

Mid Murray LAP Implementation Officer

Aimee Linke

Mid Murray LAP

PO Box 10

Cambrai

SA 5353

(08) 8564 5003

Wetland Project Officer, Lower Murray

Adrienne Frears SA MDB NRM BOARD

PO Box 2056

Murray Bridge

SA 5253

(08) 8232 6753

Wetland Management Planning Officer

Tumi Bjornsson Lower LAPS

Mt. Lofty Ranges Mount Catchment Centre Barker Upper Level Cnr. Mann and Walker St's

SA 5251

(08) 8391 7515

28

Sweeney’s Lagoon Management Plan 2006

Chapter 5. THREATS AND POTENTIAL SOLUTIONS TO SWEENEY’S LAGOON There are a number of existing and potential threats to Sweeney’s Lagoon, some of which have become apparent in the description of the wetland and available data in the chapters above. The identification of these threats is essential for appropriate adaptive management of the wetland. Their early recognition allows for an appropriate monitoring strategy for early identification of adverse impacts of management and therefore rapid response through altered management. The major threat is the lack of frequent flooding which is affecting river red gum health. Due to the wetland base being lower than the surrounding groundwater levels, a threat identified by the groundwater team is the flow of groundwater towards the wetland depression when wetland is low or dry. Therefore, evapoconcentration can lead to salt accumulation at or near the floodplain surface. There is the potential of increasing the salinity in the wetland (particularly at low wetland water levels). This interaction between the wetland and aquifer is a major parameter where wetland management can influence groundwater levels and therefore salt flow to river at high wetland levels. These and other threats identified so far have been listed in Table 12.

29

Sweeney’s Lagoon Management Plan 2006 Table 12: Existing and potential threats to Sweeney’s Lagoon THREATS

SYMPTOM Less than expected abundance of native fish

Vandalism of carp and flow control structures

Structure damaged or altered (rocks have been used to prop open carp screens)

Salinisation of the wetland if long term dry periods are introduced

Increasing EC of wetland water body Increasing salinity in wetland base/soil

Wetland maintained at a dry phase for to long allowing groundwater seepage into the wetland Salinity increase through groundwater evapoconcentration

Loss of wetland inundation

Dry wetland – loss of wetland

Inappropriate operation of locks and barrages Operation without ecological awareness Loss of water in the river

Existing

Existing

Fish barriers

Potential

Potential

ABIOTIC

CAUSE Stop logs Carp screens may restrict passage Dark passage through culvert

Vandalism

IMPACT

CATEGORY

EXTENT (IF KNOWN)

Only partial use of habitat by native fish population

Local

Wetland and adjacent reaches of river

Inappropriate management of wetland with associated adverse impact (e.g. loss of extended flood phase) No knowledge of recent management and therefore unable to fully appreciate impact of management and respond accordingly Carp access to wetland Degradation of wetland water quality (long term degradation of wetland) Degradation of wetland environment Degradation of habitat quality for native fish Reduced biodiversity (loss of some macroinvertebrates, native fish, vegetation) and flow on impacts Mainly salt tolerant species present Salt inflow into river

Local

Wetland

Local

Loss of wetland along with species dependent on the ephemeral condition of the wetland Salinisation of the wetland ‘depression’

Basin Regional

Wetland May not be a serious issue if drying is only a shortterm event. Both water quality monitoring and Macroinvertebrate taxa indicate the wetland to be in a relatively fresh state with a minor sat load. Wetland/river/ catchment

POTENTIAL SOLUTION Improve fish passage by; Upgrading the carp screens based on latest research (seek expert advice) Installing carp separation cages if research proves successful Increase light penetration in culvert (open up culvert?) Lower culvert at inlet to deepen the currently shallow passage (only to be considered as part of future upgrades/maintenance of culvert) Install secure locking mechanisms to structures

Use only annual dry events to induce germination of water plants Monitor groundwater flow around wetland to assess the impact and respond adaptively Do not allow wetland to remain dry more than 6 to 8 months

No further avoidable loss of water from the River Murray Operate locks and barrages with ecological awareness, e.g. re-establish seasonal fluctuation in water levels

30

Sweeney’s Lagoon Management Plan 2006 THREATS

SYMPTOM

CAUSE

IMPACT Loss of habitat provided by red gums Loss of ecosystem function of red gum Destruction of riparian vegetation Loss of habitat

Regional

Basin

Local

Surrounding area

Exotic species Competition with native vegetation Loss of habitat Provide shelter for rabbits and foxes

Local

Floodplain

Active removal Poisoning Contact Authorised Officer from NRM Board for control information for weed species

Local

unknown

Impact on wool (can render wool unmarketable) Physical damage to stock/wildlife Out compete other vegetation Seedlings poisonous to stock Exotic species Competition with native vegetation Loss of habitat

Regional

Wetland

Active removal Poisoning Contact Authorised Officer from NRM Board for control information for weed species Active removal Poisoning Contact Authorised Officer from NRM Board for control information for weed species

Local

Floodplain

Active removal Poisoning Contact Authorised Officer from NRM Board for control information for weed species

Competition for habitat (domination of available habitat) Predation/aggressive interaction on/with small and young native fish (redfin/gambusia) Damage to aquatic vegetation Decrease in water quality (Turbidity increase) Predation on native fish (redfin)

Local/ Regional (Managed locally)

Wetland and Sweeney’s Lagoon

Improve structure if possible Restrict carp movement into Sweeney’s Lagoon Removal of exotic species from refuge pools following drawdown Monitor abundance of invasive verses native species

Stressed river red gums

Lack of frequent flooding

Rabbits

Less diversity of vegetation to what could be expected in area Destruction of current vegetation Destruction of revegetation efforts Their presence

Rabbits eat vegetation

Golden dodder

Their presence

Potentially spreading through flooding

Californian burr

Their presence

Weeds

Their presence

Degradation of native vegetation

Invasive fish species (carp, gambusia, goldfish and redfin)

Turbid wetlands

Well known environmental problem in region (large pest population) Rapid breeding cycles (carp ~2/year), live bearing (gambusia), unpalatable eggs (redfin)

Existing

Existin g

Loss of river red gums

Potentially through spreading by birds

Potential Existing Existing Potential

BIOTIC

Existing

African boxthorn

Parasitism of crop Financial loss

CATEGORY

EXTENT (IF KNOWN)

POTENTIAL SOLUTION Red gum watering (flooding or individual watering) Maintain water in wetland for extended period (benefits fringing red gums) Fence of wetland with rabbit proof fence Baiting Shooting

31

Sweeney’s Lagoon Management Plan 2006

Chapter 6.

MANAGEMENT OBJECTIVES

The main management objective is the maintenance of the current ecology of Sweeney’s Lagoon. The Lagoon is an ephemeral wetland with a diverse and healthy species composition with vegetation providing habitat for a diverse range of native fauna. The main degradation related to the management of the wetland is the poor river red gum health, which is an issue that is currently being addressed by the floodplain pumping trials. Management of the wetland will aim to enhance the water retention in the wetland providing longer term wetting of the ringing red gums as well as providing an extended frog and fish-breeding period. The current land management practices are encouraged to remain the same to maintain the current vegetation community. Based on the objectives, presented in Chapter 1, the baseline data presented in Chapter 2 and the threats to the wetland, discussed in Chapter 5, more detailed management objectives can now be developed. The objectives, including solutions, actions needed, and priorities are detailed in Table 13. Subject to funding and council interest, the currently disconnected creeks should be connected to the wetland to allow for flooding of a greater area including these historical channels. As the channels are on crown lands, any on ground work would need to be referred to the crown lands branch of DEH, see "Your Wetland On Ground Works Document” (Sustainable Focus Pty Ltd. 2006). Adaptive management will drive the actions undertaken to achieve the objectives. Due to the complexity of the habitat requirements of water birds, native fish, macroinvertebrates and frogs and identified potential threats to the wetland, the management will need to be flexible. A minor review of the objectives and the wetland management impact is recommended at the end of each year, community groups can achieve this by reviewing their monitored data, with the support of the local wetland officers listed in Chapter 4. A major review should follow 5 years after the commencement of the management.

32

Sweeney’s Lagoon Management Plan 2006 Table 13: Management objectives for Sweeney’s Lagoon

FISH

Native Native

Invasive

VEGETATION

Native

Native

MANAGEMENT OBJECTIVES

Maintain current vegetation

SOLUTIONS

QUANTIFIABLE /MEASURE OF ACHIEVEMENT

Inform landholder of this aspect

Maintained species diversity

Work on rabbit control

Use rabbit control measures as appropriate

Expansion and survival of native species

Maintain wetland aquatic species (maintain abundance of submerged macrophytes) Removal of weeds from floodplain

Maintain ephemeral nature of wetland

Manage hydrology Acquire wetland water license

Diversity of aquatic species (no reduction in diversity)

Establish weed removal projects in the wetland area

Weed control as per expert recommendation

Reduction of weeds (as per expert recommendation)

Improve fish passage and habitat

Improve carp screen design based on expert recommendation Remove stop logs when not required for hydrological management Improve light availability in culvert Maintain deep pool refuge areas Lower (deepen) flow path through culvert (only when upgrade/maintenance allows)

Upgrade carp structure as per expert recommendation (carp separation cages if successful at other wetlands) Install stop logs only as stated in WMP – to extend inundation period Depending on budged improve culvert design to allow light penetration (open up top of culvert) Ensure deep pool refuge areas are available for native fish (remove exotics, dredge if it becomes necessary) In future upgrade/maintenance of main culvert lower structure to deepen flow path

Increase in abundance of native species Native fish survival in refuge pools Observation

Assist regeneration of riparian vegetation

Maintain current land management practises

ACTIONS (Management (M) or Engineering or structural (ES))

MONITOR (TIMING)*

LEGISLATION

PRIORITY

Vegetation survey

Medium

Photo point (Q) Vegetation survey

Low

(Y)

(Y) Photo point (Q) Vegetation survey

WAP (water license)

High

N/A

Low

(Y) Monitor water quality (M) Vegetation survey (Y)

Fish survey (1/2Y)

High

33

Sweeney’s Lagoon Management Plan 2006 Improve carp screens Install carp separation cages depending on successful trial at other wetlands Secure carp screens

Minimise presence of exotics

Remove exotics from refuge pools

Maintain native frog habitat

Install stop logs near the end of expected high river levels Manage hydrology Increase reed growth/plant

Maintained habitat for water birds (waterfowl, waders and shorebirds)

Improved frog breeding by extending inundation period Maintain hydrology regime Increase fringing vegetation (sedges/rushes) to provided habitat Maintain grass habitat at frog monitoring site 2 Maintain all habitat including open water, shallow water, wet and dry mud

Maintain hydrology regime

Maintain bird abundance and diversity using wetland

Minimise groundwater impact on wetland

Do not dry out wetland for more than a 6 to 8 month period

Maintain current hydrology regime Monitor impact of dry period on wetland salinity

Monitor wetland salinity following drying event (no net increase) No increase in groundwater discharge

Establish cause of high nutrient levels

Monitor nutrient levels in wetland during inundated phase

Monitor nutrient levels in wetland during inundated phase

Assessment of monitored time series of nutrient levels

Install locking mechanisms

Structure secure with no vandalism

BIRDS

Native

Discuss screen improvement with expert Install screens prior to inundation of wetland Install locking mechanism Remove exotics during fish survey in refuge pools

Minimal carp recruitment Less carp (no large carp) in wetland and refuge areas

Fish survey (1/2Y)

High

Reduced presence of exotic fish abundance (native to exotic ration) Maintained presence of specialist native frog species in wetland (no loss over 5 year management period)

Fish survey (1/2Y)

Medium

MANAGEMENT

Structural

WQ

GW

Native/Migratory

FROGS

Invasiv e

Invasive

Minimise impact of carp

Secure structure from vandalism/inappropriate operation (carp screen and flow control structure)

Install locking mechanisms

Frog survey (1/3

WAP (water license)

High

Bird survey (1/2Y) Observation

WAP (water license)

Medium

Y)

Monitor water quality (M) Monitor ground water (Q) Monitor one piezometer with data logger to assess interaction between river levels and groundwater levels (1 year/during high river level fluctuation) Monitor wetland nutrient levels Observation

High

Low

High

* WQ, Water Quality; W, Weekly; M, Monthly; Y, Yearly; Q, Quarterly

34

Sweeney’s Lagoon Management Plan 2006

Chapter 7.

IMPLEMENTATION OF PLAN

The wetland was found to be in a healthy state with a diverse range of flora and fauna. The maintenance and minor enhancement of this condition is the best way to ensure the maintenance of this richness. Therefore, the River Murray Wetlands Baseline Survey – 2005 vegetation, fish, frog and bird teams (EBS & HydroTas 2006; SA MDB NRMB 2006; SARDI Aquatic Sciences 2006b; SARDI Aquatic Sciences 2006a) recommended the maintenance of the ephemeral nature of the wetland. This recommendation has been accepted as a central part of this management plan. Should the river return to the more fluctuation water levels as seen in Figure 13, where the river exceeded the flow threshold of the wetland every moth of the year, a new management strategy may need to be devised to maintain the ephemeral nature of the wetland! Such a situation would allow a greater range of manipulations to be explored and can only be of benefit to the region.

7.1

ON GROUND ACTION AND TIMETABLE

From the objectives described above, a number of required actions have been identified. Table 14, provides a timetable and prioritisation for the actions to be undertaken as part of the management of Sweeney’s Lagoon. The table does not address monitoring which is discussed in Chapter 8. A log of all activities undertaken at the wetland should be maintained. This log would assist in the review process of the wetland management plan discussed in Chapter 9.

35

Sweeney’s Lagoon Management Plan 2006 Table 14: Implementation plan for Sweeney’s Lagoon

POSSIBLE

AS SOON AS

ACTIVITY

TIMETABLE

RESPONSIBILITY

High

Finance

ASAP

LAP (Aimee Linke)

Install fish screens

High

Fish screens

ASAP

Community group

Weed control as per expert recommendation

Low

Funding

As per expert recommendation

LAP/Community group

Medium/Low

Finance

As appropriate

LAP (Aimee Linke)

Low

Finance

With structure upgrade

LAP (Aimee Linke)

Medium

Finance

As appropriate

LAP (Aimee Linke) consult with Ben Smith

Improve structure as necessary (install carp separation cages is successful at other wetlands)

Low

Finance

As appropriate

LAP (Aimee Linke) consult with Ben Smith

Ensure deep pool refuge areas remain available for native fish

High

Monitoring fish (nets, license etc.) Dredge if necessary

Ongoing

Community group with assistance from LAP and SA MDB NRM BOARD

Remove exotic fish during monitoring of deep pool refuge areas

High

During monitoring

Ongoing

Community group with assistance from LAP and SA MDB NRM BOARD

Study nutrient over time in wetland (1 season)

Medium

Funding

ASAP

Community group with assistance from SA MDB NRM BOARD

Improve structure as necessary (lower flow barrier) Improve structure as necessary (improve carp screens) AS APPROPRIATE

RESOURCES

Improve structure as necessary (install secure locking mechanisms)

Improve structure as necessary (convert culvert to open tope to allow light penetration)

Rabbit control

Low

Funding (fence, poison, shooting etc.)

As appropriate

Community group with assistance from LAP and SA MDB NRM BOARD

Install groundwater salinity data logger

High

Funding

ASAP

LAP and SA MDB NRM BOARD

Medium

Funding

As appropriate

LAP and SA MDB NRM BOARD

Monitor impact of dry period on salinity (1 season when river levels fluctuate)

ANNUAL

PRIORITY

Annual review of monitored data

High

Monitored data

End of each inundation year (End of summer)

Community group with assistance from LAP and SA MDB NRM BOARD

Install stop logs when required

High

2 persons 3 hrs

When the wetland is high and the river level is expected to fall

Community group

Remove stop logs when not required

High

2 persons 3 hrs

When wetland levels are just above the flow path restriction

Community group

36

Sweeney’s Lagoon Management Plan 2006

7.2

WETLAND WATER OPERATIONAL PLAN

One of the strongest tools in managing a wetland is the control of the wetland hydrology. Hydrology controls the germination and growth of aquatic and riparian vegetation. The healthy vegetation and appropriate inundation leads to the growth of biofilms, the vegetation, and biofilms being a food source for macroinvertebrates and small native fish. The vegetation and appropriate water regime also provide a more diverse habitat for waterbirds and fish. In Sweeney’s the ephemeral nature of the wetland is to be maintained. Hydrological management in this case is therefore aimed at maintaining this ephemeral nature and enhancing the inundation period to promote frog breeding. (a)

WATER REGIME

The water regime at Sweeney’s wetland is dependent on the seasonal fluctuations below Lock 1. That is, based on the height of the flow path of 0.854 m AHD it is anticipated that the wetland will receive water for 4 month of the year when the connection is left open as the river is expected to rise above this restriction as observed in the past below Lock 1. The connection is then closed off from the river in order to hold water at a slightly higher level than anticipated if the wetland is left to follow the expected change in river level. The wetland then enters a slow drying phase followed by a fully dry phase until the cycle is repeated the following September, see Figure 14. In s ta ll s to p lo g s

R e m o v e s to p lo g s

~ 0 .9 7 m A H D

~ 0 .9 4 m A H D

~ 0 .9 0 m A H D

N o te : C a rp s c re e n s in s ta lle d a n d s e c u re d

S e p te m b e r

O c to b e r

Novem ber

Decem ber

O p e n c o n n e c tio n to riv e r - in u n d a tio n o f w e tla n d

J a n u a ry

F e b ru a ry

M a rc h

A p ril

S to p lo g s in s ta lle d - w e tla n d d ryin g

M ay

June

J u ly

A ugust

D ry w e tla n d – F is h m a in ta in e d in re fu g e p o o ls

Figure 14: Water regime

(b) VOLUME CALCULATIONS The volume calculations are based on the median monthly anticipated wetland levels following inundation of the wetland, the fill volume (Table 15) and the expected monthly evaporation based on the median monthly surface area (Table 16). The base of the wetland is at 0.43 m AHD, inflow commences at 0.854 m AHD (SKM 2006c). Stop logs are installed at the end of December to extend the period that the wetland has water The baseline survey provided estimates of the volume within the wetland at five different depths. These depths did not include all the depths required for this wetland. Therefore, to obtain the water volume required at the depths expected each month, a polynomial relationship was established between the depth of the water in the wetland and the volume (both given in the SKM baseline survey data). Equation 1, established to calculate the volume at a given depth for the main lagoon, where volume is in m3 and depth in metres, had an R2 of 1. Equation 1:

Volume

122551

Depth

2

289308

Depth

129253

The evaporation rates were attained using the Wetland Loss Calculator obtained from RMCWMB. Equation 2 with an R2 of 1 was used to estimate the surface area (m2) of the wetland exposed to evaporation in each month when the wetland was inundated based on the expected wetland depth (the used wetland depth is directly dependent on the calculated median river levels for each month). The details of the estimated volume of evaporation used for the calculation of water requirements can be seen in Table 16 along with the calculated surface area based on Equation 2. 37

Sweeney’s Lagoon Management Plan 2006 Equation 2:

Area

29560

2

Depth

111453

Depth

50689

Table 15: Water required over fill period of Sweeney’s Lagoon Month

Median River Level m AHD(1)

Depth aimed for

Wetland surface area (ha) at a given depth

Volume in wetland ML(2)

Fill volume required per month (ML)

32

0

~2.6

Volume required per month (ML) Including evaporation 0 (5.1)

Notes

Jan.

0.81

~0.47

Drying (5.1 ML evaporation)

Feb.

0.76

N/A

Drying

Mar.

0.7

N/A

Drying

Apr.

0.69

N/A

Drying

May

0.71

0

Dry

June

0.71

0

Dry

July

0.76

0

Dry

Aug.

0.8

0

Dry

Sep.

0.94

0.51

2.8

34

34

36.9 (34+2.9)

Filling

Oct.

0.97

0.54

3

36

2

4.8 (2+2.8)

Extra filling

Nov.

0.97

0.54

3

36

0

5.2

Evaporative maintenance only

Dec.

0.9

0.47

2.6

32

-4 (3)

1.2 (-4+5.2)

Evaporative maintenance offset by flow back to river

Total 1.

2. 3.

48.1

Monthly median calculated from the daily water level obtained from the, DWLBC Surface Water Archive (DWLBC 2006) for 1996 through to 2006 (if the river returns to a more wet state as can be seen in Figure 13 then the wetland operation and water use will have to be reviewed) Based on the median river level This is where the river level is expected to drop, therefore flows are expected to return to the river (evaporation is still relevant)

Table 16: Calculated water loss (evaporation – precipitation) JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

Area used in calculation (ha)

2.6

2.8

3.0

3.0

2.6

Net Loss (ML)

5.1*

2.9

2.8

5.2

5.2

TOTAL (ML)

16.1

Water loss obtained using the Wetland Loss Calculator and based on anticipated water levels (surface area) each month * Not relevant to total as this is during the draw down phase

This water use calculation can be seen in Table 15 and is summarised Table 17. The total annual allocation requirement for Sweeney’s Lagoon annually amounts to 50 ML (or 50,000 kL). At the end of each inundation season a review of monitored data is required to assess the impact of the hydrology, this would be as part of an annual review of the wetland management plan. An annual review of the WMP is essential for best practice management to guide efforts according to the vision and therefore objectives. This will assist to assess whether the current management of is an effective hydrology management strategy or whether a revision of the wetland management plan is required. Table 17: Water use calculation Total Fill Volume (ML)

Flow back to river (ML)

Total Potential Evaporation (ML)(1)

Total Annual Water Requirement (ML)(2)

36

4

16.1

50

1. 2.

Obtained using Wetland Loss Calculator (Oct., Nov., Dec. & Jan. only) Rounded to nearest 10 ML

The area used for volume estimates within the wetland can be seen in Map 2. This shows that through this management only the main lagoon receives water. The second lagoon is therefore still dependent on flood periods, which have reduced substantially in frequency. Floodplain/river red gum watering is therefore still required at Sweeney’s Lagoon for river red gum health and for the 38

Sweeney’s Lagoon Management Plan 2006

simulation of flooding in the higher wetland areas. Pumping should attempt to be undertaken following a similar pattern as shown in Figure 14 with a gradual increase in water levels over two to three months followed by a slow drying event. As the wetland will not be connected to the river during pumping projects as scheduled in this management plan fish migration will be retarded. This impact should be taken into consideration for repeat watering trials weighing up the needs of the red gums, frogs, and fish. As floodplain pumping projects cannot be scheduled into this management plan, and their full impacts are currently not known, future scheduling should be made with consideration of this management plan and in consultation with the relevant wetland management planner or wetland officer. The salinity impact of wetland management was to be estimated using the SIWM model. However, the Department of Water Land and Biodiversity Conservation (DWLBC) has withdrawn the use of the SIWM model. Some inherent difficulties were found in developing and finalising this model for general use leading to a new modelling approach to be undertaken. DWLBC is presently developing a new model for the simulation of the impact wetland management will have on salt accumulation within wetlands, as well as, the potential impacts to the river. A salinity assessment will be conducted on Sweeney’s Lagoon once a model is available for use; a brief report outlining the results of this modelling will be included in the plan in the future.

39

Sweeney’s Lagoon Management Plan 2006

Chapter 8.

MONITORING

For the development of a wetland management plan, Sweeney’s Lagoon was included in the River Murray Wetlands Baseline Survey - 2005 (SKM 2006b). The data collected during this survey provided a basis by which objectives for the wetland management could be refined, hydrology guidelines could be developed, and review procedures scheduled. However, this data did not cover all the issues related to managing the Sweeney’s Lagoon. Partly as a consequence, but also as part of adaptive management and best practise wetland management, monitoring of the wetland has been devised to answer some of the unknowns, the monitoring schedule can be seen in Table 18. Ongoing monitoring during wetland management plays a role in adaptive management by providing managers with information on how the wetland is responding to management strategies, whether the objectives are being met, whether there are off-target implications (wetland in regional context) or (as per Your Wetland: Monitoring Manual (Tucker 2004)) whether the Golden Rules are being broken. The Golden Rules being: Don’t salinise your wetland Don’t kill long lived vegetation Don’t destroy threatened communities or habitats of threatened species To ensure that monitored data is available for evaluation, review and reporting, a log of all activities, monitoring and site description should be maintained at an accessible and convenient location. The purpose of such a log is to maintain a record of management steps undertaken, their justification, and observed impacts/implications. The maintenance of a log is both good management practice, allowing future reference to potential impacts of management, and a requirement of the Wetland Water License. The data will ultimately be stored in appropriate databases. Refer to Your Wetland: Monitoring Manual (Tucker 2004) for examples of data log sheets and further description of monitoring methods.

40

Sweeney’s Lagoon Management Plan 2006 Table 18: Monitoring plan for Sweeney’s Lagoon. Parameter

Method

Priority

Groundwater

Level and conductivity (1 piezo. data logger)

Medium/High (data logger)

Water quality monitoring (cond., turb., & temp.)

Medium

Surface level (using gauge boards)

Low

Surface Water

Fish

Seine net, dip net (and fyke nets if deep enough)

SEP

OCT



NOV

DEC

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

Time Required

Responsible

Q

Q

Q

Q

1 monitoring day event

Community Group/ Wetland Officer

Q

Q

Q

Q

1 monitoring day event

Community Group/ Wetland Officer







0.5 hour

High



Q

1 monitoring day event

Community Group/ Wetland Officer

2 hours

Community Group/ Wetland Officer

1 monitoring day event

Community Group/ Wetland Officer

1 monitoring day event

Community Group/ Wetland Officer

0.5 hour

Community Group/ Wetland Officer

0.5 day

To be resolved

1 monitoring day event (not including identification)

Community Group/ Wetland Officer

Medium Photopoint monitoring Vegetation Quadrat/line intercept Tree health Frogs Birds

Macroinvertebrates

Recording Calls Fixed area search

Dip net survey

Q Medium

Low

Q



High High

Q

 

Q

 Q

Q

Low Q



Q

Community Group

Q = at some time in the quarter

41

Sweeney’s Lagoon Management Plan 2006

Chapter 9. 9.1

EVALUATION, REVIEW AND REPORTING

EVALUATION AND REVIEW

The full impact of a wetland management cannot be fully predicted. Therefore, the data obtained through monitoring need to be regularly reviewed to respond to impacts of the management strategy. A review, of the implications of management of Sweeney’s Lagoon therefore needs to be an ongoing process. For the wetland management plan to be an adaptive and complete document, periodic reviews need to be scheduled in following monitoring and evaluation of the impact of management. An annual review of the monitored data and the condition of the wetland should be conducted by the community group with assistance from the LAP and the SA MDB NRM Board. This first review should be scheduled following the drying and wetting cycle of the wetland. A full review of the wetland management plan should be scheduled in 5 years. For the annual review to be effective it needs to include an upgrade of the; Hydrological regime based on new knowledge and understanding, e.g. whether the inundation of the wetland has occurred and its implications wetland water quality and habitat development (see management objectives Chapter 6) Monitoring schedule to reflect changes in the wetland management plan

9.2

REPORTING

The wetland management plan for Sweeney’s Lagoon is comprehensive and includes an estimation of the water requirements over the period covered in this plan. Should the volume used deviate substantially from the plan, and therefore the water license, the Department of Water Land and Biodiversity Conservation (DWLBC) will need to be notified. The records noted in the activity and monitoring logs will assist in reporting to DWLBC. Further, as part of the requirements of the water license, any substantial change in the wetland management plan, e.g. objectives, monitoring timetable or hydrology regime change, also needs to be reported to DWLBC.

42

Sweeney’s Lagoon Management Plan 2006

REFERENCES AWE (2006). Groundwater Surveys. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. Barnett, S. R. (1989). The Hydrogeology of the Murray Basin in South Australia with Special Reference to the Alluvium of the River Murray Floodplain. Moorundi Wetlands Groundwater Monitoring Network: Case Study - Morgan's Lagoon. K. Holland, CSIRO Land and Water. BOM (2005). Climate Averages. Accessed 27 June 2005, http://www.bom.gov.au/climate/averages/tables/cw_024018.shtml. DEH (2003). 2003 Review of the Status of Threatened Species in South Australia: Proposed Schedules under the South Australian National Parks and Wildlife Act 1972. National Parks and Wildlife Council in partnership with the Department for Environment and Heritage: 61. Discussion Paper, Adelaide DWLBC (2006). Unpublished Data. Department of Water, Land and Biodiversity Conservation. EBS & HydroTas (2006). Bird Surveys. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. Frears, A. P. (2006). Personal Communication. Wetland Project Officer, Lower Murray South Australian Murray-Darling Basin Natural Resources Management Board. Jensen, A., F. Marsh, et al. (1999). Wetland Managment Study: Moorundi Wetland Complex. Wetland Care Australia. Berri Jensen, A., P. Paton, et al. (1996). Wetlands Atlas of the South Australian Murray Valley. South Australian River Murray Wetlands Management Committee. South Australian Department of Environment and Natural Resources. ADELAIDE Jensen, A. and R. Turner (2002). Moorundi Wetland Complex Management Plan. Wetland Care Australia. Berri MDFRC (2006). Water Quality Surveys. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. Murray-Darling Ministerial Council (1998). Floodplain Wetlands Management Strategy: For the MurrayDarling Basin. Murray-Darling Basin Commission. A component of the Natural Resources Management Strategy, Canberra RMCWMB (2002). Water Allocation Plan for the River Murray Prescribed Watercourse (as Amended 12th January, 2004). River Murray Catchment Water Management Board, Government of South Australia. Berri, South Australia RMCWMB and DWLBC (2003). Guidelines for Development of Wetland Management Plans for the River Murray in South Australia. River Murray Catchment Water Management Board, Department of Water Land and Biodiversity Conservation,. Rover, C. (2006). Personal Communication. Project Manager - Remediation and Infrastructure, Infrastructure & Business, Dwlbc. 43

Sweeney’s Lagoon Management Plan 2006

SA MDB NRMB (2006). Frog Surveys. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. SARDI Aquatic Sciences (2006a). Fish Surveys. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. SARDI Aquatic Sciences (2006b). Vegetation Surveys. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. SKM (2006a). Macroinvertebrate Surveys. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. SKM (2006b). River Murray Wetlands Baseline Survey - 2005. South Australian Murray Darling Basin Natural Resources Management Board. SKM (2006c). Site Physical Survey. River Murray Wetlands Baseline Survey – 2005, South Australian Murray Darling Basin Natural Resources Management Board. Smitt, C., I. Jolly, et al. (2003). Moorundi Wetlands Groundwater Monitoring Network: Case Study - Morgan's Lagoon. CSIRO Land and Water. South Australian River Murray Wetlands Management Committee (SARMWMC) (1996). Management of Wetlands of the River Murray Valley: Draft Action Plan 1996-1999. Wetlands Management Program: Department of Environment and Natural Resources. Adelaide Sustainable Focus Pty Ltd. (2006). Your Wetland: Guidelines for on-Ground Works: Draft. SA MDB NRM Board. Thompson, M. B. (1986). River Murray Wetlands, Their Characteristics, Significance and Management. Department of Environment and Planning and Nature Conservation Society of S.A. Adelaide Tucker, P. (2004). Your Wetland: Monitoring Manual - Data Collection. River Murray Catchment Water Management Board, Australian Landscape Trust. Renmark SA Tucker, P., M. Harper, et al. (2002). Your Wetland: Hydrology Guidelines. Australian Landscape Trust. Renmark SA

44

Sweeney’s Lagoon Management Plan 2006

Appendix A.

Wetlands Atlas Data

Table 19: Wetland Atlas Data

FID AREA PERIMETER WETLANDS# WETLANDS-ID AS2482 AUS_WETLANDNR THOM_WETLANDNR THOM_CHANGE WETLAND_NAME COMPLEX_NAME CONS_VALUENR MDBC_DISTNR WATER_REGIME INTERNATIONAL NATIONAL BASIN VALLEY HIGH_CONSERVATIO MODERATE_CONSERV LOW_CONSERVATION SHOULD_REASSESS SHOULD_ASSESS

Side Lagoon

Main Lagoon

656

657

62451.64

83321.73

948.2673

2015.97

656

657

655

656

44190

44190

S0100

S0100

Y

Y

BLANCHETOWN FLAT

BLANCHETOWN FLAT

PORTEE COMPLEX

PORTEE COMPLEX 2

2

4

4

TEMPORARY

TEMPORARY 0

0

0

0

1

1

1

1

1

1

1

1

0

0

1

1

0

0

Source: Wetlands Atlas of the South Australian Murray Valley (Jensen et al. 1996)

45

Sweeney’s Lagoon Management Plan 2006

Appendix B. Baseline Survey Locations

Source: River Murray Wetlands Baseline Survey – 2005 (SKM 2006b)

46

Sweeney’s Lagoon Management Plan 2006

Appendix C.

Baseline Survey DTM

Source: River Murray Wetlands Baseline Survey – 2005 (SKM 2006c)

47

Sweeney’s Lagoon Management Plan 2006

Appendix D.

Baseline Survey Groundwater

Source: River Murray Wetlands Baseline Survey – 2005 (AWE 2006)

48

Sweeney’s Lagoon Management Plan 2006

Appendix E. Baseline Survey Vegetation 372750

.0 0 0 0 0 0

373000

.0 0 0 0 0 0

.0 0 0 0 0 0

373250

373500

.0 0 0 0 0 0

373750

.0 0 0 0 0 0

374000

.0 0 0 0 0 0

374250

.0 0 0 0 0 0

.0 0 0 0 0 0

6197500 .0 0 0 0 0 0

6197250 .0 0 0 0 0 0

6197000

6197000

.0 0 0 0 0 0

6197250

.0 0 0 0 0 0

6197500

.0 0 0 0 0 0

5

.0 0 0 0 0 0

6196750 402750

.000000

403000

.000000

403250

6196500

.000000

.000000

6196000

3

3

1

4

6228500

4

5

5

5

6

4 5 4 3 43 2 5 3 3 5 3 3 1 3

45 2

6

5

3

5

5

6228000

.000000

6195750

5 5

5

6

4 5

5

.0 0 0 0 0 0

.0 0 0 0 0 0

3

4

54

44

4 45 5

.000000

3

3 3

4

2

6228250

6196250

.0 0 0 0 0 0

2

.000000

2

.0 0 0 0 0 0

402500

6196250

.000000

.0 0 0 0 0 0

402250

6195500

6195500

.0 0 0 0 0 0

.000000

6228000

.0 0 0 0 0 0

1 1

.0 0 0 0 0 0

6228250

.000000

6228500

.000000

6196500

.0 0 0 0 0 0

1

6196000

3

6195750

6196750

3

.0 0 0 0 0 0

.0 0 0 0 0 0

3

372750 402250

.000000

.0 0 0 0 0 0

373000 402500

.0 0 0 0 0 0

373250

.000000

S u rv e y e d Q u a d ra ts C he no p o d shrub la nd

.0 0 0 0 0 0

402750

373500

.0 0 0 0 0 0

.000000

403000

373750

.0 0 0 0 0 0

.000000

20 40 M u e h le n b e ckia flo ru le n ta shrub0 la nd

E le oc h a ris a c u ta s e d g elan d M u e h le n b e c k ia floru le n ta s h ru blan d o v er M y riop h y llu m v e rru c os u m

Boggy Flat

S p or ob olu s m itc h e llii gr as s lan d

1 :1 0 ,0 0 0

80 120 160 0 35 70 140 210 Metres

.0 0 0 0 0 0

M y riop h y llu m v e rru c os u m h er blan d

S w e e n e y's L a g o o n

1:5,500 M yrio p h yllu m ve rru co su m sub m e rg e d he rb la nd

374250

E u c a ly p tu s c a m a ld u le n s is v ar. c a m a ld u le n s is / E u c a ly p tu s la rg iflore n s w o o dlan d*

Eucalyptus camaldulensis

E le o ch a ris a cu ta se d g e la nd

.0 0 0 0 0 0

.000000

L a rg e -s c a le V e g e ta tio n C o m m u n itie s

R IV E R M U R R A Y RIVER MURRAY W EBASELINE TL A N D S B A S E L IN E W ETLANDS SURVEY S U R V E Y

S p o ro b o lu s m itch e llii g ra ssla nd C he no p o d shrub la nd

374000 403250

280 M e tre s

* D e n o te s co m m u n ity n o t q u a n tita tiv e ly su rv e ye d * D e n o te s co m m u n ity n o t q u a n tita tiv e ly su rv e ye d # D e n o te s a re a to o sm a ll to m a p # D e n o te s a re a to o sm a ll to m a p Q u a d ra t n u m b e rs re fe r to v e g e ta tio n a sso cia tio n s in w e tla n d su m m a ry

E u c a ly p tu s c a m a ld u le n s is v ar. c a m a ld u le n s is o v er M u e h le n b e c k ia floru le n ta #

Area of interest shown in red box

M u e h le n b e c k ia floru le n ta s h ru blan d C h en o p o d s h ru blan d

A g ros tis a v e n a c e a gr as s lan d + /- E u c a ly p tu s la rg iflore n s # *

Source: River Murray Wetlands Baseline Survey – 2005 (SARDI Aquatic Sciences 2006b)

49

3 7275 0

.0 0 0 0 0 0

3 7300 0

.0 0 0 0 0 0

3 7325 0

.0 0 0 0 0 0

3735 00

.0 0 0 00 0

3737 50

.0 0 0 00 0

3740 00

.0 0 0 00 0

3742 50

.0 0 0 0 00

4 4

1

1

5 5

3 4 4 1

.0 0 0 0 00

6196 750

4 5 4 3 4 3 2 5 5 3 2 3 5 33 1

4 4

5

3

5

5

5

5

6 2 2 8 5 0 0 .0 0 0 0 0 0

.0 0 0 0 00

6196 250

5

4

3 7250 0

.0 0 0 0 0 0

3 7275 0

.0 0 0 0 0 0

402250

.0 0 0 0 0 0

3 7300 0

.0 0 0 0 0 0

3 7325 0 402500

.0 0 0 0 0 0

3735 00

.0 0 0 0 0 0

.0 0 0 00 0

402750

3737 50

.0 0 0 00 0

.0 0 0 0 0 0

3740 00 403000

.0 0 0 0 0 0

.0 0 0 00 0

3742 50

6195 500

.0 0 0 0 00

6 2 2 8 0 0 0 .0 0 0 0 0 0

.0 0 0 0 0 0

5

3

3

5 3

3

1

403250

4 5

4 4

2

4

2 4 3

4 .0 0 0 0 0 0

1

445 5

3

.0 0 0 0 0 0

6195 750

.0 0 0 0 0 0

6 1960 00

6 2 2 8 2 5 0 .0 0 0 0 0 0

3

403000

1 3 3

1

2

4 4

2

3

3

.0 0 0 0 0 0

5

6 2 2 8 2 5 0 .0 0 0 0 0 0

402750

1

5

6 1957 50

.0 0 0 0 0 0

6 2 2 8 5 0 0 .0 0 0 0 0 0

402500

6 1962 50

.0 0 0 0 0 0

.0 0 0 0 0 0

1 5

6 2 2 8 0 0 0 .0 0 0 0 0 0

.0 0 0 0 0 0

6 1965 00

402250

1 4

4

.0 0 0 0 00

3

6196 500

2

1

.0 0 0 0 00

2

3

6196 000

6 1967 50

3 4

3 1 1 4 1 5 4 3

.0 0 0 0 00

.0 0 0 0 0 0

6 1970 00

6197 000

.0 0 0 0 00

.0 0 0 0 0 0

6 1972 50

6197 250

.0 0 0 0 00

.0 0 0 0 0 0

6 1975 00

6197 500

.0 0 0 0 00

.0 0 0 0 0 0

6 1977 50

6197 750

.0 0 0 0 0 0

5

6198 000

.0 0 0 0 0 0

.0 0 0 0 00

3 7250 0

.0 0 0 0 00

Sweeney’s Lagoon Management Plan 2006

.0 0 0 0 00

403250

.0 0 0 0 0 0

R IVER R M IV U RERRA YM U R R A Y W E T LAWN E DT S LBAAN SE DLSINBEA S E L IN E S U R V E YS U R V E Y E u ca ly ptu am E su c a ly ap ldule tu s cns a is m a ld u le n s is

o gon g y F la t S w ee ne y's L B ago 1 :1 1,0 001 :5 ,5 0 0 0

40 8 0

60 0 21 0 40

2 84 0

1 32200 1 6 0 M e tr es M e tr e s

A re a o f i n t e re s t sh o A wn b ot ex r e s t s h o w n in r e d b o x r eian re o fd in

Source: River Murray Wetlands Baseline Survey – 2005 (SARDI Aquatic Sciences 2006b)

50

Sweeney’s Lagoon Management Plan 2006 .0 00 0 0 0

372 750

.0 0 0 0 0 0

373 000

.0 0 0 0 0 0

3 7325 0

.0 0 0 0 0 0

3735 00

.0 0 0 00 0

3737 50

.0 0 0 00 0

37 4000

.0 0 0 0 0 0

37 4250

.0 0 0 0 0 0

402250

402500

402750

5

.0 0 0 0 0 0

403000

.0 0 0 0 00

6196 750 .0 0 0 0 0 0

403250

.0 0 0 0 0 0

.0 0 0 0 0 0

3

4

5

5 5 45 5 5

4 5 5

3 5

43 2 25 33 353 1

4

4

.0 0 0 0 0 0

.0 0 0 0 00

3 5

5

3

5

55 5 5

5

3725 00

.0 00 0 0 0

372 750 402250

.0 0 0 0 0 0

.0 0 0 0 0 0

373 000

.0 0 0 0 0 0

402500

3 7325 0

.0 0 0 0 0 0

.0 0 0 0 0 0

3735 00 402750

.0 0 0 00 0

3737 50

.0 0 0 0 0 0

.0 0 0 00 0

403000

37 4000 .0 0 0 0 0 0

.0 0 0 0 0 0

37 4250 403250

.0 0 0 0 0 0

6195 500

.0 0 0 0 00

6228000

.0 0 0 0 0 0

.0 0 0 0 0 0

3

4

4 5

3

6196 8250 6 2 2000

4 1

4 4 4 5 5 5 24 5 4 5

44

445 5

5

5

.0 0 0 0 00

.0 0 0 0 0 0

6228250

5

3

4

4 44 55

6196 250

.0 0 0 0 00

6228500

.0 0 0 0 0 0

4

6 1962 50

.0 0 0 0 0 0

.0 0 0 0 0 0

3 .0 0 0 0 0 0

5

5

.0 0 0 0 0 0

3

6 1960 00 6 1957 50

4 4

6228500

4

4 4

000 0 0 0 .0 0 0750 6 2 2 86195

6 1965 00

.0 0 0 0 0 0

1

5 5 5 4

.0 0 0 0 00

6 1967 50

4

6196 500

.0 0 0 0 0 0

6 1970 00

6197 000

.0 0 0 0 00

.0 0 0 0 0 0

6 1972 50

6197 250

.0 0 0 0 00

.0 0 0 0 0 0

6 1975 00

6197 500

.0 0 0 0 00

.0 0 0 0 0 0

6 1977 50

6197 750

.0 0 0 0 0 0

5

.0 0 0 0 00

3725 00

.0 0 0 0 0 0

IVEERRMMUU AY RRI V RR RR AY W AA SS EL EE WEETTLA L ANNDDSSBB E IN L IN SSUU RR VV EE YY E a lypt p tu a mflo a ld u le E uu cc aly uss lac rgi ren s n s is g g yL ago F la ton S w ee B neoy's ,5 000 0 11:1:51,0 0

4 00 28004 0

8 00 1 2 24 0 01 6 0 32 0 16 M e tre M es tr e s

inste s twsnh ionwren dinb ore A re A a re o f ai no t ef re t re sh o x d box

Source: River Murray Wetlands Baseline Survey – 2005 (SARDI Aquatic Sciences 2006b)

51

Sweeney’s Lagoon Management Plan 2006

Appendix F. Species List for Sweeney’s Lagoon (a) FLORA OF SWEENEY’S LAGOON Table 20: Plant Associations at Sweeney’s Lagoon Association number **

Species

Common name

Acacia stenophylla

River cooba

Agrostis avenacea*

Common blown-grass

x

Aster subulatus*

Aster-weed

x

Atriplex prostrata

Creeping Saltbush

x

x

Atriplex semibaccata

Berry Saltbush

x

x

Atriplex stipitata

Bitter saltbush

Avena barbata*

Bearded Oat

Azolla filiculoides

Pacific Azolla

Bromus unioloides*

Prairie grass

Carpobrotus rossii

Angular Pigface

Carrichtera annua*

Ward's Weed

Chenopodium pumilio

Small Crumbweed

Chloris truncata

Windmill grass

Craspedia sp.

Billybuttons

Cyperus gymnocaulos

Spiny Flat-sedge

x

Eleocharis acuta

Common Spike-rush

x

Enchylaena tomentosa

Ruby Saltbush

Eremophila gibbifolia

Coccid Emubush

Eremophila scoparia

Scotia Bush

Eucalyptus camaldulensis var. camaldulensis

River Red Gum

Eucalyptus largiflorens

River Box

Euphorbia terracina*

False Caper

Graminae sp.

Grass

Helichrysum scorpoides

Button Everlasting

Helichrysum sp.

Everlasting

Juncus usitatus

Common Rush

Lycium ferocissimum*

African Boxthorn

Maireana enchylaenoides

Wingless Bluebush

Maireana microcarpa

Swamp Bluebush

Marrubium vulgare*

Horehound

Marsilea drummondii

Nardoo

1

2

3

4

5

6

x x

x x

x x

x

x x

x

x x

x

x

x

52

Sweeney’s Lagoon Management Plan 2006 Medicago sp.*

Medic

Mesembryanthemum crystallinum*

Common Iceplant

Muehlenbeckia florulenta

Lignum

Myriophyllum verrucosum

Red Milfoil

Osteocarpum acropterum var. acropterum

Water Weed

Persicaria lapathifolium

Pale Knotweed

Phragmites australis

Common reed

Rorippa palustris*

Yellow Marsh-cress

Schismus barbatus*

Arabian Grass

x

Sclerolaena divaricata

Tangled Bindyi

x

Sonchus oleraceus*

Common Sow-thistle

x

Sporobolus mitchellii

Rat-tail couch

Stipa sp.

Spear grass

Typha sp.

Bulrush

Vulpia sp.*

Fescue

Wahlenbergia fluminalis

River Bluebell

TOTAL

x

x

x x

x x

x

x

x

x

x

x

x x

9

8

x

12

7

1

4

The above list includes opportunistic observations not surveyed in quadrats *denotes exotic species ** Association numbers; 1. Chenopodiaceae shrubland in dry central lagoon 2. Sporobolus mitchellii grassland on dry lagoon bed 3. Chenopodiaceae shrubland in depression on Blanchetown golf course 4. Eleocharis acuta sedgeland on edge of main lagoon 5. Myriophyllum verrucosum submerged herbland in main lagoon 6. Muehlenbeckia florulenta shrubland in main lagoon Source: River Murray Wetlands Baseline Survey – 2005 (SARDI Aquatic Sciences 2006b)

53

Sweeney’s Lagoon Management Plan 2006 Table 21: Ongoing vegetation surveys Voucher

Common Name

Species name

VEG01

Creeping saltbush

Atriplex semibaccata

Red gum

VEG02

Yellow button

Eucalyptus camaldulensis Craspedia sp?

VEG03

Dead grass

Agrostis avenaceae?

VEG04

Round-leaf thistle

Sonchus sp

VEG05 VEG06 VEG07

Tube leave Long thin grass Burr Medic Lignum

VEG08 VEG09 VEG10 VEG11

Spiny Sedge

Cyperus gymnocaulos

Clover Small purple Sock grass

VEG17

Muehlenbeckia florulenta

Fly traps

VEG13 VEG15

Medicago polymorpha

Spade leaf

VEG12 VEG14

Sporobulus mitchelli?

Spiny Lignum

Muehlenbeckia horrida

White leaf Typha

Typha sp

VEG18

Common spike rush

Eleocharis acuta

VEG19

Juncus sp1

Juncus sp

Azolla

VEG20

Water-milfoil Water couch

Azolla filiculoides Myriophyllum verrucosum? Paspalum distichum

VEG22

Giant Sedge

Cyperus exaltus

VEG29

Spiky Plant

Bassia sp?

VEG28 VEG23 VEG24

Green leafy saltbush Tall water grass Aster

Atriplex sp Glycenia maxima? Aster subulatus

VEG25

Common nardoo

Marsilea drummondi?

VEG27

Lesser joyweed

Alteranthera denticulata?

Herbarium ID

SWEVG01

SWEVG02

Atriplex semibaccata

*

*

Eucalyptus camaldulensis

*

Xerochrysum bractiatum

*

Lachnagrostis filiformis

*

Sonchus olenaceus

*

*

?Chenopod sp.

*

*

Sporobolus mitchellii

*

*

Medicago polymorpha

*

Muehlenbeckia florulenta

*

*

Atriplex ?prostrata

*

*

Cyperus gymnocaulos

*

*

Carrichtera annua

*

*

Phyla nodiflora

*

Chomaecyse drummondii

*

Vulpia myuros

*

Muehlenbeckia horrida

*

Lepidium sp.

*

Typha orientalis

*

Eleocharis acuta

*

Juncus subsecundus

*

Azolla filiculoides

*

Myriophyllum verrucosa

*

*

Paspalum distichum

*

*

Cyperus exaltus

*

Thick water grass

*

* *

Bassia sp?

*

Atriplex suberecta

*

Amphibromus nervosus

*

Aster subulatus

*

Marsilea drummondi

*

Alteranthera denticulata

* *

Liliocomes acuta

VEG26

*

Glyceria sp?

Lachnagrostis filiformis

*

Source: Adrienne Frears SA MDB NRM Board (2006)

54

Sweeney’s Lagoon Management Plan 2006 Photographs on left by Adrienne Frears on 5th Dec 2005. Photographs on right by Wayne Brice on 24th June 2006.

55

Sweeney’s Lagoon Management Plan 2006

56

Sweeney’s Lagoon Management Plan 2006

(b) BIRDS Table 22: Habitat features identified in Sweeney’s Lagoon Habitat Feature

Autumn 13/04/05 1pm

1 fixed location, 1 transect

Spring 21/10/05 12:30pm

1 fixed location, 1 transect

SweBi01

SweBi02

SweBi01

SweBi02

Shoreline

simple

simple

simple

complex

Fringing Vegetation

patchy low cover

patchy low cover

patchy low cover

patchy low cover

Reeds

absent

occasional

absent

occasional

Sedges

occasional

occasional

occasional

occasional

Herbs

extensive

occasional

occasional

extensive

Wet mud

absent

absent

occasional

occasional

Dry mud

extensive

occasional

occasional

occasional

Hollow-bearing trees

occasional

occasional

occasional

occasional

Perching trees

occasional

occasional

occasional

occasional

Fringing River Red Gums

occasional

occasional

occasional

occasional

Water’s edge

dry

1-10m from vegetation

in or above vegetation

in or above vegetation

Water Depth (m)

dry

0.5

1-Feb

<0.5

rising

same

Water Level Source: River Murray Wetlands Baseline Survey – 2005 (EBS & HydroTas 2006).

Table 23: Bird species observed at Sweeney’s Lagoon Common Name

Scientific Name

Autumn

Spring

Total abundance

Conservation status

Waterbirds Australian Shelduck

Tadorna tadornoides

2

2

M

Australian Wood Duck

Chenonetta jubata

2

2

M

Pacific Black Duck

Anas superciliosa

2

2

M

Grey Teal

Anas gracilis

101

101

M

Little Pied Cormorant

Phalacrocorax melanoleucos

1

1

Australian Pelican

Pelecanus conspicillatus

60

60

White-faced Heron

Egretta novaehollandiae

1

1

Intermediate Egret

Ardea intermedia

1

1

State R

Great Egret

Ardea alba

1

1

M

Australian White Ibis

Threskiornis molucca

5

5

Straw-necked Ibis

Threskiornis spinicollis

15

15

Yellow-billed Spoonbill

Platalea flavipes

2

2

Black-fronted Dotterel

Elseyornis melanops

1

1

M

Masked Lapwing

Vanellus miles

4

4

M

Clamorous Reed-warbler

Acrocephalus australis

3

3

M

Little Grassbird

Megalurus gramineus

6

6

M

Total

Individuals

0

207

207

Species

0

16

16

Nankeen Kestrel

Falco cenchroides

1

1

Chestnut-rumped Thornbill

Acanthiza uropygialis

4

4

Southern Whiteface

Aphelocephala leucopsis

2

2

Mistletoebird

Dicaeum hirundinaceum

2

2

Total

Individuals

9

0

9

Species

4

0

4

Terrestrial species

Conservation Status: M = Migratory Source: Murray Wetlands Baseline Survey – 2005 (EBS & HydroTas 2006).

57

Sweeney’s Lagoon Management Plan 2006 Table 24: Habitat use by waterbird species at Sweeney’s Lagoon

R

8

Anas gracilis

F

60

Phalacrocorax melanoleucos

R

Australian Pelican

Pelecanus conspicillatus

R

White-faced Heron

Egretta novaehollandiae

F

1

1

Intermediate Egret

Ardea intermedia

F

1

1

Great Egret

Ardea alba

F

1

1

Threskiornis molucca

R

5

5

Straw-necked Ibis

Threskiornis spinicollis

R

15

15

Yellow-billed Spoonbill

Platalea flavipes

F

Black-fronted Dotterel

Elseyornis melanops

F

1

1

Masked Lapwing

Vanellus miles

F

2

2

Masked Lapwing

Vanellus miles

R

2

2

Clamorous warbler

Acrocephalus australis

F

Megalurus gramineus

F

Little Cormorant

Australian Ibis

Pied

White

Reed-

Little Grassbird

Total 2

2

2

2

2

2

38

30

63

3

1

1

60

60

2

2

1

72

Total

Samphire

Anas gracilis

Grey Teal

Willows

Grey Teal

Grass

R

Dead logs logs

Anas superciliosa

Reg gums

Pacific Black Duck

Lignum

R

Wood

Shallow water

Chenonetta jubata

Australian Duck

Mud

R

Sedges

Tadorna tadornoides

Reed beds

Australian Shelduck

Open water

Scientific Name Activity

Common Name

1

8

85

0

2

3

6

6

8

0

33

0

0

0

207

Activity: F = Feeding, R = Roosting/resting Source: River Murray Wetlands Baseline Survey – 2005 (EBS & HydroTas 2006).

(c) FISH Table 25: Fish survey sites Site #

Habitat description

Method

Autumn

Spring

1

Lignum stand, firm substrate, submerged grases, relatively clear water, 40 cm deep

Bait Trap

X

X

2

Inlet channel, drying pool, sparse Azola and emergent reeds in riparian zone, 50 cm deep

FykeNet

X

X

3

Inlet channel, sparse vegetation on edge, 1.2 m deep

Gil Net

4

Open clear water, firm substrate with dense submerged gras and algae, 30 cm deep

Seine

5

Dense Lignum patches, clear water in main lagoon, 40 cm deep

FykeNet

X

6

Inlet channel,drying pool, sparse Azola andemergent reeds in riparian zone, 50 cm deep

Backpack E-Fishing

X

7

Flooded terrestrial riparian grasses, relatively clear water, 40 cm depth

Backpack E-Fishing

X

8

Inlet channel, 10cm.s-1 flow, submerged and emergent grasses, some rocks, 10-60 cm deep

Backpack E-Fishing

X X

X

Source: River Murray Wetlands Baseline Survey – 2005 (SARDI Aquatic Sciences 2006a)

58

Sweeney’s Lagoon Management Plan 2006 Table 26: Fish captured at Sweeney’s Lagoon

Common Name

Species Name

Native Fishes bony hering

Nematalosa erebi

flathead gudgeon

Philypnodon grandiceps

carp complex

Hypseleotri ssp.

Potential reproduction* X

gudgeon

Australian smelt

X

Autumn

Spring

Length (TL, mm)

Length (TL, mm) Count

Count

Ave

Min

Max

3

107

57

140

13

46

35

56

1

55

55

55

14

178

36

22

48

384

36

18

51

562

12

55

51

64

12

4

37

31

42

4

Retropina semoni

Threatened Native Fishes unspecked hardyhead C.s. fulvus dwarf-flathead gudgeon

Philypnodon sp.

Murray rainbowfish

Melanotaenia fluviatilis

Exotic/Invasive Fish common carp Cyprinus carpio gold fish

Carasius auratus

red fin

Perca fluviatilis

eastern gambusia

Gambusia holbroki

Number of fish Number of native fish Number of exotic fish

1

38

38

Ave

Total

Min

Max 3

38

1 1

38

38

38

1

X

6

419

84

610

3

44

35

60

9

X**

29

76

46

109

1

180

180

180

30

3

162

145

182

108

25

17

34

X**

3 2

43

37

48

110

341

408

749

195

402

597

146

6

152

8

11

8 Count of species Native to Invasive ratio (Species) Native to Invasive ratio (number of fish) Source: Adapted from River Murray Wetlands Baseline Survey - 2005 (SARDI Aquatic Sciences 2006a) * Believed to have reproduced within or adjacent to the wetland (SARDI Aquatic Sciences 2006a) ** autumn only

1.8 3.9

59

Sweeney’s Lagoon Management Plan 2006

(d) MACROINVERTEBRATES Table 27: Habitat at sample location Site

Habitat a

Habitat (%)

1

Emergent macrophytes

2

Emergent macrophytes

a

length

Habitat b

Habitat (%)

60

Detritis

40

60

Submerged macrophytes

30

b

length

Habitat c

Habitat (%)

Detritis

10

c

length

Source: River Murray Wetlands Baseline Survey - 2005 (SKM 2006a)

Table 28: Macroinvertebrates captured at Sweeney’s Lagoon Higher taxa Turbellaria

Family

Subfamily/Genus

Dugesiidae

Nematoda Gastropoda

Spring Site 1

50 Ancylidae

Ferrissia

Planorbidae Physidae

Physa

Site 2

Total abundance

130

130

40

90

30

30

140

140

130

130

Acariformes: Hydracarina

Eylaidae

Decapoda

Atyidae

Paratya

Collembola

Sminthuridae

Katianna

10

Coleoptera

Dytiscidae

larvae

30

Hydrophilidae

Berosus

20

Ceratopogonidae

Ceratopogoninae

30

30

Tanypodinae

50

50

Diptera

Orthocladinae Chironomidae

Chironominae

120

Ephemeroptera

Baetidae

immature

30

Hemiptera

Corixidae

immature

190

Micronecta

10

Notonectidae

immature

1170

Odonata

Lestidae

immature

40

Trichoptera

Hydroptilidae

Hellyethira

30

Leptoceridae

Triplectides

20

Total abundance Total number of taxa

10

10

20

20

20

30 30

20

40

20

20

230

350 30

50

240 10

2850

4020 40

10

40 20

2100

3400

5500

17

11

21

Source: River Murray Wetlands Baseline Survey - 2005 (SKM 2006a)

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