1. Environmental watering – CEWH 2016
Improved native fish breeding success: Golden perch,
Silver perch, Murray hardyhead, Bony bream, Murray cod and rainbowfish and gudgeon species.
Native bird breeding boom, including first of internationally
protected Eastern great egrets since 2011, following
environmental water to the Yanga National Park in early 2015.
Significant increases in waterbird species diversity and total abundance at sites that received environmental water in
Gwydir river system
Revegetation stabilising banks in Goulburn River system
Improved dissolved oxygen and black water mitigation

2. Just add water
2750GL and 3200GL targets derived from models aiming to deliver flow rates in river sections, not environmental outcomes in key indicator or high value sites.
Assumption that flow targets will deliver overbank flooding to achieve desired environmental outcomes ‘naturally’.
Constraints:
Regulatory, physical, environmental, socio-economic
Obtaining flood easements
Upgrading roads, bridge and other infrastructure
Flood mitigation works – ie, levees
Increasing dam outlet capacities
$200 m for above measures
Constraints restrict environmental watering to
in-stream, riverbank and lower floodplain.
Environmental offset works and measures to improve
extent of environmental watering and its success

3. 450GL upwater and relaxed constraints “Hydrologic modelling of the relaxation of operational constraints in the southern connected system: Methods and results”. October 2012, MDBA.
Region
Location
Existing constraint ML/d
Relaxed constraint in model ML/d
Murray
Hume to Yarrawonga
25,000
40,000
Downstream of Yarrawonga
22,000
Lower Darling
Weir 32/increase Menindee outlet capacity
9300
18,000
Darling Anabranch
Water flows into anabranch over 9300 ML/d (no regulator)
Regulator added and closed >9300 ML/d when water supplied for enviro in Murray
Murrumbidgee
Gundagai
30,000
50,000
Balranald
9000
13,000
Goulburn
Seymour
12,000
15,000
McCoy’s Bridge
20,000

4. Environmental effects
Flows increased from 60,000 ML/d to 80,000 ML/d at SA border
40% of wetlands inundated vs 75% between Darling River and Lock 1 (additional 60,000 ha of Chowilla/Riverland, watering to mid-level floodplain)
* 27,500 ML/d Swan Hill late October 2016; **94,600 ML/d at SA border last week November 2016
Frequency
Pre-1788
Pre-Basin Plan
2800GL
3200=RC
3 years
10 years
8 years
5.5 years
High-flow targets: 450GL, relaxed constraints – possible improved bird breeding
35,000 ML/d for 30 days at Barmah-Millewa forest
40,000 ML/d for 60 days at Gunbower-Koondrook-Perricoota
20,000 ML/d for 150 days at Gunbower-Koondrook-Perricoota*
70,000 ML/d for 42 days at Hattah Lakes
80,000 ML/d for 30 days at Riverland-Chowilla floodplain**

5. Lower lakes, Coorong and Murray Mouth
Subtle environmental outcomes but environmental indicators unlikely to be particularly sensitive compared with upstream sites that rely on high flows to inundate mid-high floodplain levels. (Note: Keystone species Ruppia tuberosa seagrass salinity tolerance range: up to 80-90g/l
Indicator
BP Target
Pre-1788
2009 baseline
2800 GL BP
3200 GL BP - RC
Average salinity in Coorong southern lagoon
Less than 60g/l 24 62 44 41
Max. days salinity over 130 g/l in southern Coorong
323
% years salinity <100 g/l in southern Coorong
>95%
100%
82%
96%
Average salinity in Coorong northern lagoon
Less than 20g/l 12 29 21 20
Max. days salinity over 50 g/l in northern Coorong
604 75
Lower Lakes level (mAHD)
0.4m AHD
-0.4m (Jan 2009)
0.4m (Jan 2003)
0.2m (Jan 2009)
0.7m (Jan 2003)
Murray mouth bed level
-1m
-2.5m 2009
-2.5m 2003
0.0m (Jan 2009)
-0.5m (Jan 2003)
-0.5m (Jan 2009
-1.5m (Jan 2003)
-0.5m (Jan 2009)
-1.0m (Jan 2003)

6. MDBA conclusions “Hydrologic modelling of the relaxation of operational constraints in the southern connected system: Methods and results”. October 2012, MDBA.
If constraints can be overcome, likely to be increased ecological benefits for floodplains, particularly if combined with great water recovery. (pxiv)
Work done previously by MDBA shows increasing impacts on communities of water recovery greater than 2750GL/y, and this was an important consideration in MDBA’s proposed ESLT. (pxiv)
Overcoming constraints:
“This would require a commitment and significant investment from both State and Federal governments and would be subject to further assessments, cost/benefit analysis (including assessments of any third party impacts) and extensive community consultation.” (piv)
- Federal water special account has $200 million budget for addressing constraints