Commonwealth environmental water
use options 2013-14:
Northern Unregulated Rivers
1
Cover image credit: Darter chicks at Narran Lakes. Photo by Simon Banks © CEWO.
Acknowledgement of the Traditional Owners of the Murray-Darling Basin
The Commonwealth Environmental Water Office respectfully acknowledges the Traditional
Owners, their Elders past and present, their Nations of the Murray– Darling Basin, and their
cultural, social, environmental, spiritual and economic connection to their lands and waters.
This report should be cited as ‘Commonwealth environmental water use options 2013-14: Northern Unregulated Rivers’.
Published by the Commonwealth Environmental Water Holder for the Australian Government.
© Commonwealth of Australia 2013.
This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by
any process without prior written permission from the Commonwealth. Requests and enquiries concerning
reproduction and rights should be addressed to Department of Sustainability, Environment, Water, Populations and
Communities, Public Affairs, GPO Box 787 Canberra ACT 2601 or email public.affairs@environment.gov.au
Information presented in this document may be copied for personal use or published for education purposes, provided
that any extracts are fully acknowledged. The views and opinions expressed in this publication are those of the authors
and do not necessarily reflect those of the Australian Government or the Minister for Sustainability, Environment, Water,
Population and Communities. While reasonable efforts have been made to ensure that the contents of this publication
are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the
contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use
of, or reliance on, the contents of this publication
2
Commonwealth environmental water use options
2013-14: Northern Unregulated Rivers
Table of contents
1. Introduction ........................................................................................................ 5
1.1.
Description of the region.......................................................................................................... 5
2. Context for water use in 2013-14 in the Northern Unregulated Rivers .......... 7
2.1.
Delivering environmental water to the Northern Unregulated Rivers ............................. 7
2.2.
Operational and management considerations for 2013-14 in the Northern
Unregulated Rivers .................................................................................................................... 8
2.3.
Valley condition ....................................................................................................................... 11
3. Water availability ............................................................................................. 13
3.1.
Commonwealth environmental water holdings in the Northern Unregulated
Rivers for 2013–14 ..................................................................................................................... 13
3.2.
Other sources of environmental water allocations .......................................................... 13
3.3.
Natural or unregulated flows and planned environmental water ................................ 13
4. Planning for water use in the Northern Unregulated Rivers in 2013-14 ....... 15
4.1.
Planning for a range of inflows in 2013-14 .......................................................................... 15
4.2.
Implementing watering actions throughout the year ...................................................... 15
5. Water use options and the Basin Plan’s environmental watering objectives
........................................................................................................................... 16
5.1.
Demonstrating how Commonwealth environmental water in 2013-14 will
contribute to the Basin Plan’s Environmental Watering Plan objectives –
Northern Unregulated Rivers ................................................................................................. 16
6. Water use options for 2013-14 ........................................................................ 18
6.1.
Watering options...................................................................................................................... 18
6.2.
Assessment of environmental watering options ................................................................ 25
7. Accounting for the use of Commonwealth environmental water .............. 26
7.1.
Water use accounting ............................................................................................................ 26
7.2.
Operational monitoring .......................................................................................................... 26
8. Partnerships ...................................................................................................... 27
9. Bibliography ..................................................................................................... 28
3
List of Figures
Figure 1: Northern Unregulated Rivers showing the location of existing Commonwealth holdings.
6
List of Tables
Table 1: Operational considerations for the Northern Unregulated Rivers in 2013–14.
10
Table 2: Catchment conditions in the northern unregulated catchments 2007–08 to 2012–13. 12
Table 3: Commonwealth environmental water holdings in the Northern Unregulated Rivers as
at 30 April 2013.
13
Table 4: Expected outcomes from the use of Commonwealth environmental water in the
Northern Unregulated Rivers.
17
4
1. Introduction
This document is designed to be read in conjunction with the Commonwealth environmental
water use options 2013-14: Planning approach, which outlines the approach to planning for
the use of Commonwealth environmental water this coming water year. The planning
document provides the context for key aspects of the approach including determining
resource availability, the expected outcomes from watering actions and the relationship
between the function of the Commonwealth Environmental Water Office (the Office) and the
Basin Plan.
This document outlines watering options for the use of Commonwealth environmental water in
the Northern Unregulated Rivers this year. The options, which describe potential watering
actions, series of actions, or watering strategies, do not represent a commitment for water use.
Consistent with the Office’s framework, decisions to make water available for any of the
potential options will be subject to an assessment against five published criteria (available from
the Office’s website) and seasonal, operational and management considerations at the time
of the action. All relevant watering actions will be assessed to ensure the best possible use of
environmental water within the relevant planning area and across the Murray-Darling Basin
and having regard to the Murray-Darling Basin Authority’s Basin annual environmental watering
priorities, once published.
1.1.
Description of the region
This document covers the northern-most streams of the Darling Basin (known as the ‘Northern
Unregulated Rivers’) and the Commonwealth environmental water holdings that provide
access to unregulated flows.
The streams for which water use options have been developed are shown in Figure 1 and
comprise:

The Queensland and NSW portions of the Warrego, Moonie, Nebine Creek and
Condamine-Balonne catchments.

A short reach in the upper catchment of the Queensland Border Rivers (Severn River) and
small unregulated holdings in the main stem (Macintyre River) of that system.

1,640 km of the Barwon-Darling River as far as Menindee Lakes.
Options for the Commonwealth’s regulated water holdings in the Border Rivers are covered in
a separate annual water use options document.
These catchments are predominantly unregulated systems in which the majority of water use
occurs by diversion of river and overland flows (water that breaks out of a watercourse as
floodwater or runs across the land after rainfall) during episodic flow events. Water taken from
unregulated sources is stored in large, shallow floodplain storages typically hundreds of
megalitres to tens of gigalitres in capacity, including a few of several hundred gigalitres, known
as ‘ring tanks’ or ‘turkey nest’ dams.
5
Figure 1: Northern Unregulated Rivers showing the location of existing Commonwealth holdings.
6
2. Context for water use in 2013-14 in the
Northern Unregulated Rivers
2.1.
Delivering environmental water to the Northern Unregulated Rivers
The delivery of environmental water in the Northern Unregulated Rivers depends on rain
events, entitlement type and conditions, and water shepherding arrangements.
Entitlement type
At present the Commonwealth’s holdings are the only held environmental water in the
northern unregulated river catchments. Current Commonwealth unregulated holdings
comprise unsupplemented water allocations in Queensland in the Warrego, Lower Balonne,
Nebine Creek, Moonie and Border Rivers catchments and unregulated river access licences in
the NSW Warrego and Barwon-Darling Rivers (see section 3.1).
Environmental water from these holdings cannot be ‘ordered’ and generally cannot be actively
‘delivered’ to achieve specific in-stream or wetland outcomes. To date Commonwealth
environmental water has been left in-stream during unregulated flow events for local and
downstream flow benefits. How far flow benefits extend through the system depends on the
circumstances for individual flow events.
A special high flow access licence on the Warrego River at Toorale National Park/State
Conservation Area is the only entitlement in the region for which there is a degree of choice as
to its utilisation. This flexibility is due to regulating structures in the lower Warrego River which
may be operated to bias delivery to the Warrego River Western Floodplain area or alternatively
to the lower Warrego and Darling Rivers and potentially the lower Murray River system.
Access to unregulated holdings is typically specified in entitlement conditions by river flow
thresholds. Annual and/or multi-year volumetric limits and maximum daily take rates provide a
ceiling on the volume that can be taken in any given year, however, the ability to utilise this
volume depends on flow events that trigger access to the entitlement.
Water shepherding
Leaving environmental water in-stream carries the potential risk that the additional flows are
extracted by downstream users in a particular event. The protection of this water (water
shepherding) currently relies on existing water resource management systems including the
Murray-Darling Basin Cap on diversions (specified for each valley) and existing rules governing
the access of other users to unregulated flows. Additional arrangements for the Northern
Unregulated Rivers are also being developed through the Commonwealth’s water
shepherding projects with the New South Wales and Queensland governments.
The degree of protection of environmental flows (ie the risk of extraction) varies between river
valleys. Key factors include the location of the entitlement, access arrangements and
behaviour of downstream water users and the type of flow.

In the Lower Balonne and main stem of the Border Rivers system in Queensland, access to
unsupplemented water is governed by an announcement system based on flow at
common reference points in the catchment. For example, access for water users in the
Lower Balonne depends on flows at St George. All announcements provide for each user’s
share of available flow irrespective of prior and intended future use. Inherently these
systems provide a high degree of protection to the Commonwealth’s share of in-stream
flows, although there may still be a risk of extraction in particular flow conditions and/or
locations within catchments.
7

In the Barwon-Darling the risk of extraction of Commonwealth environmental water in
2013-14 is considered to be low. The long-term yield of entitlements in this system is 100 per
cent and combined with the existing Cap on diversions there is no potential for growth in
use by other users to take up the Commonwealth’s share of in-stream flows. Long term
average flows will reflect the additional environmental water from held entitlements.

Event-based impacts are also expected to be minor. There is potential for some flow from
the Commonwealth entitlement on the Barwon River near Collarenebri and residual flows
from held entitlements in NSW and Queensland tributary streams to be extracted in
particular flow events. For extraction to occur, however, the Commonwealth’s share of
stream flow on its own must cause a flow access threshold for the next entitlement class to
be exceeded. For example, the Commonwealth’s share alone must cause access for
downstream users to increase from Class A to Class B, at which higher rates of extraction
are permitted. This is unlikely given the small volume of flows expected from upstream
entitlements relative to other flows in the system during unregulated flow events.

The risk of extraction is moderate in the Queensland Moonie, upper Warrego and Severn
River (upper Border Rivers) because the access conditions of downstream users potentially
do allow them to extract some of the additional in-stream flow. The contribution that
Commonwealth environmental water makes to unregulated flows in these areas, however,
is small relative to other flows in the system. Overall the impact on flows is expected to be
minor, although could be significant in some conditions. For example, in relatively low flow
and/or short duration flow events in which take by downstream users is limited by
opportunity rather than access conditions.

Event-based extraction risk is very low for flows derived from Queensland and NSW
entitlements on the lower Warrego River because there are no major active users located
below the Commonwealth entitlements and the end of the system at Menindee Lakes.

Water shepherding arrangements combined with measures to prevent growth in use,
including Cap and SDLs, will address existing risks in the longer term.
2.2.
Operational and management considerations for 2013-14 in the
Northern Unregulated Rivers
Operational and management considerations in 2013–14 relate to water shepherding
arrangements and to managing the utilisation (account balances) of entitlements for which
carryover is available.
Key considerations are described below. Their relationship to inflows under different scenarios is
shown in Table 1.
With respect to water shepherding arrangements in 2013–14:

The Queensland entitlements in Nebine Creek, Moonie and Border Rivers (Severn) were
‘gifted’ to the Commonwealth and are ineligible for shepherding beyond the QueenslandNSW border. Gifted entitlements in the Queensland Warrego catchment may be
shepherded to Menindee Lakes but not beyond. The strategy for the gifted entitlements in
2013–14 is to use them to contribute to in-stream flows in essentially the same manner an
irrigator would use them, that is, to ‘take’ flows at every opportunity until the available
annual volume is exhausted.

Stage 1 of the joint Commonwealth-NSW water shepherding project was completed in
late 2012. Stage 2, which will include further consideration of options to shepherd water
through the Menindee Lakes and subsequent implementation in relevant legislation and
water resource plans, is expected to commence in mid-late 2013. These arrangements are
unlikely to be available for 2013–14.
8

Arrangements used in trials in 2008–09 and 2010–11 to shepherd flows from Toorale for use
below Menindee Lakes are unlikely to be feasible whilst the Lakes remain under the control
of the Murray-Darling Basin Authority and rules in relevant NSW water sharing plans and the
Murray-Darling Basin Agreement apply.

Arrangements for shepherding environmental water within Queensland are yet to be
developed, therefore managing entitlements to achieve specific downstream outcomes
with shepherded water is not feasible in 2013–14.
With respect to managing utilisation (account balances) to provide flexibility of use in future
years and to maximise long-term water yield:

Queensland unsupplemented water in the Warrego, Moonie, Border Rivers and Nebine
Creek and the special high flow licence on the NSW Warrego River at Toorale are subject
to annual use limits and no carryover applies. In 2013–14 these holdings will be used at all
available opportunities until the annual volumetric limit is exhausted.

Water from Commonwealth entitlements in the NSW Barwon-Darling and Warrego Rivers
and unsupplemented water in the Lower Balonne in Queensland can be carried over to
future water years. Where possible utilisation of these entitlements will be managed to
optimise volumes that could be shepherded to the lower Murray-Darling in future years.

Accounting rules for NSW Warrego river access licences and Queensland Lower Balonne
entitlements allow carryover of 100 per cent of entitlement volume or volumetric limit
respectively. Accounts are generally credited with 100 per cent of these volumes as an
annual allocation. Annual use is limited to 200 per cent of the entitlement volume
(Warrego) or volumetric limit (Lower Balonne). The Warrego licences are also subject to a
300 per cent use limit over any three consecutive years.

Unused account balances effectively only enhance the volume available in the following
year for the Lower Balonne entitlements and up to the next two years in the case of the
NSW Warrego river access licences. As long-term arrangements are not expected to be
implemented within these timeframes, deferring or limiting use of these entitlements in
2013–14 is not likely to enhance potential future volumes available for shepherding through
downstream systems.

Accordingly, in 2013-14 Lower Balonne entitlements will be used at all available
opportunities until the multi-year account balance is exhausted. Account balances in the
Lower Balonne are expected to be between 100 and 200 per cent of the volumetric limit
at season’s start (see Section 3.1).

It may also be appropriate to use up account balance of the Warrego river access
licences to help ensure long-term water yield and flow outcomes in the Warrego. These
licences were unused in 2012–13 due to an absence of trigger flows (as at 9 May 2013),
and 200 per cent of entitlement volume (16.2 GL) is available for use in 2013–14.

Unlimited carryover of unused allocation applies for Barwon-Darling licences. In 2013–14
and on ongoing basis, utilisation of Commonwealth licences in this system will be limited to
the annual allocation so as to preserve accrued account balance as a reserve for future
shepherding below Menindee Lakes and/or in-catchment watering actions.
9
Table 1: Operational considerations for the Northern Unregulated Rivers in 2013–14.
Inflow scenario
Very low
inflows
Low
inflows
Moderate
inflows
High
inflows
Very high
inflows
Opportunities
Contribute to unregulated flows in the
Barwon-Darling and beyond at times
when Menindee Lakes is spilling.
Use environmental water in
conjunction with naturally occurring
river flows.
This opportunity is applicable across all inflow scenarios
and catchments.
Use existing Toorale Warrego River instream infrastructure to increase flows
in the lower Warrego and Darling
River downstream.
Constraints
Neither long-term or ad hoc
shepherding arrangements to enable
the use of water from northern basin
entitlements for outcomes
downstream of Menindee Lakes is
likely to be available in 2013–14.
This constraint is applicable across all inflow scenarios
and catchments.
Flows sufficient to reach higher
floodplain areas (eg Culgoa River
floodplain, Toorale Western
Floodplain) may not occur.
Commonwealth environmental water
will enhance in-stream flows but if
other unregulated flows are
insufficient the environmental water
needs of key assets may not be met.
This constraint is applicable across all inflow scenarios
and catchments.
Risks*
Perception that Commonwealth
environmental water increases
inundation impacts to property and
infrastructure.
Irrigation diversions may reduce short
term local benefits of environmental
water and limit how far benefits
extend downstream (all catchments).
*See Section 6.2 for more information on risk management.
10
2.3.
Valley condition
Between 2000 and 2010 the northern unregulated river valleys predominately received low
inflows due to a long period of drought which had a significant effect on the environmental
condition of the region. The impacts of the drought period are captured in the Sustainable
Rivers Audit 2: the ecological health of rivers in the Murray-Darling Basin at the end of the
Millennium Drought (based on data collected from 2008 to 2010). The majority of the Northern
Unregulated Rivers’ valleys were found to have poor river ecosystem health with the exception
of the Warrego valley that was in moderate river ecosystem health (Davies et al 2012).
In the three years prior to 2012-13 the northern unregulated catchments experienced very wet
conditions providing large flows to river channel assets, distributary systems and floodplain
wetlands across the region. These beneficial flooding flows contributed to recovery of assets
affected by drought or drier than average conditions in the previous decade. For example,
flood flows in the Condamine-Balonne River have supported large scale breeding and
recruitment of waterbirds in Narran Lakes and significant riparian and floodplain vegetation
responses during 2008–09, 2009–10 and 2011–12. Catchment condition, as indicated by
cumulative annual streamflow at selected locations across the northern unregulated
catchments, are shown at Table 2 (for locations of gauging stations refer to Figure 1).
During 2012–13 catchment conditions across the Northern Unregulated Rivers have been
predominately moderate. Exceptions are the Lower Balonne which experienced high inflows
and the Warrego and Nebine Creek catchments which were essentially dry. In the Lower
Balonne heavy rainfall in January and February 2013 from ex-tropical cyclone Oswald resulted
in flooding across south-east Queensland and coastal New South Wales. Though the majority
of the heavy rainfall and flooding occurred east of the Great Divide, large areas of the
Queensland and northern New South Wales Murray-Darling Basin catchments also received
heavy rainfall with some major flooding, though significantly less than the floods seen during
the record-breaking La Niña events of 2010-11 and 2011-12 (Bureau of Meteorology 2012).
11
Table 2: Catchment conditions in the northern unregulated catchments 2007–08 to 2012–13.
Gauge
Catchment
(period of
records)
Recent annual streamflow~
2007–08
2008–09
2009–10
2010–11
2011–12
2012–13
High
Low
Very low
Highest
on
record
Low
Moderate
High
Moderate
High
Moderate
Border
Rivers
Severn River
at Farnbro
- Upper
(1962–2012)
- Lower
Macintyre
River at
Goondiwindi
(1980–2012)
Low
Moderate
Very low
Highest
on
record
Moonie
Nindigully
(1969–2012)
High
Moderate
Very high
Highest
on
record
Lower
Balonne
St George
(1971–2012)
Moderate
Very low
Very high
Highest
on
Very high
record
Low
Very low
Highest in
the last 5
years
Very high
Moderate
High
Very high
Low
Very high
Very
high
Very high
Very low
Very high
Very low
Very high
Very
high
High
Very low
Moderate
Low
Moderate
Very
High
Low
Very Low
Moderate
Very
High
Nebine
Creek *
Warrego
- Upper
(Qld)
- Mid (Qld)
- Lower
(NSW)
Barwon
Darling
(NSW)
-Upper
- Mid
Roseleigh
Crossing
(2007–2012)
Augathella
(1967–2012)
Wyandra
(1966–2012)
Ford’s Bridge
(1972–2012)
Collarenebri
(1980–2012)
Bourke
(1943–2012)
Very
low
High
Very low
Very Low
Highest
on
Very high
record
Very low
Highest
Moderate
on record
Highest
since
1998–99
Moderate
Notes:
~ Annual catchment streamflow were defined at key locations by: Very low up to 17.5 per
cent rank, Low 17.5 – 37.5 per cent rank, Moderate 37.5 – 62.5 per cent rank, High 62.5 – 82.5
per cent rank, Very High greater than 82.5 per cent rank. Data Sourced from NSW Office of
Water (NSW sites) and Queensland Department of Natural Resources and Mines (Queensland
sites)
* Qualitative information only. Gauged flow data is insufficient to classify annual streamflow in
the Nebine Creek catchment.
12
3. Water availability
3.1.
Commonwealth environmental water holdings in the Northern
Unregulated Rivers for 2013–14
Commonwealth environmental water holdings available for use in 2013–14 in the Northern
Unregulated Rivers are shown in Table 3 below.
Table 3: Commonwealth environmental water holdings in the Northern Unregulated Rivers as
at 30 April 2013.
Entitlement type
Entitlement held
(GL)
Long-term
average annual
yield (GL)
Estimated
Carryover from
2012–13 (GL)
Forecast water
availability for
2013–14 (GL)2
Border Rivers –
Severn
1.0
0.5
N/A
up to 1,0
Border Rivers –
Macintyre
3.3
1.3
N/A
up to 4,9
Moonie River
1.4
1.1
N/A
up to 1,4
Nebine Creek
5.9
1.0
N/A
up to 5,9
Condamine
Balonne1
47.0
32.4
-
up to 73.2
Warrego River
33.9
25.8
8.1
up to 42.0
Barwon-Darling
22.3
22.3
46.0
up to 56.6
Total
114.7
84.5
54.1
152
Notes:
1. After these options were developed a small volume of water was acquired in the
Condamine system, use options and accounting arrangements are being confirmed.
2. Maximum able to be used under entitlement conditions subject to announcement of
trigger flows.
The full list of Commonwealth environmental water holdings can be found at
http://www.environment.gov.au/ewater/about/holdings.html and is updated monthly.
3.2.
Other sources of environmental water allocations
There are currently no other sources of held environmental water in the northern unregulated
river catchments.
3.3.
Natural or unregulated flows and planned environmental water
In addition to water entitlements held by the Commonwealth, environmental demands may
also be met via water provided for the environment under rules in state water plans (referred to
as ‘planned environmental water’).
Rules limiting extraction of unregulated flows by users, such as commence/cease to take flow
thresholds and daily, annual and multi-year use limits, form the basis of planned environmental
water in the Northern Unregulated Rivers. They are complemented by rules in a few areas
which defer or reduce extraction during specific types of flows. Event-based rules are
13
triggered by antecedent conditions such as time since last flow in the target range and/or
timing and the frequency of target flows in recent times.
Key flow event protection rules in the region are:

Lower Balonne - low and medium flows and flows likely to fill Narran Lakes

Warrego - dry spell breaking flows

Barwon-Darling - flows for algal suppression, fish passage and to meet critical water needs.
Other than in the Warrego these rules have a relatively minor effect on enhancing in-stream
flows and mitigating extraction.
It is not possible to actively manage the timing and extent of augmentation of particular rules–
based planned environmental water in a particular flow event via use of existing held
environmental water entitlements in the northern unregulated river valleys. The extent to which
Commonwealth environmental water contributes to the ecological objectives targeted by
planned environmental water, however, may be determined following a flow event.
14
4. Planning for water use in the Northern
Unregulated Rivers in 2013-14
4.1.
Planning for a range of inflows in 2013-14
For current Commonwealth holdings resource availability in the Northern Unregulated Rivers is
determined solely by natural or unregulated flows and planned environmental water in the
system (Section 3.3). Unlike in regulated catchments, water cannot be accessed from storages
and there are no physical carryover volumes.
The magnitude and pattern of individual flow events during the year is the main determinant of
water availability and whether ecologically significant flow thresholds are met. Measures of
mean or average stream flow do not capture the variability in flows or the hydrologic
characteristics of individual flow events and hence are not a strong indicator of likely
ecological outcomes.
Given the highly variable nature of rainfall experienced across the Basin, short-term or annual
inflows cannot be forecast with precision. For this reason water use planning in the northern
unregulated river catchments in 2013–14 has been based on the full range of catchment
inflow scenarios that may occur.
4.2.
Implementing watering actions throughout the year
In November 2012 the Commonwealth Environmental Water Holder approved the ongoing
use, for in-stream purposes, of unregulated water entitlements (existing holdings and new
registrations) in the Queensland Murray-Darling Basin streams and NSW Barwon-Darling River.
The decision means that in-stream contributions of Commonwealth environmental water will
be accounted for at all available opportunities (subject to trigger flows) up to the maximum
permissible annual volume for Queensland entitlements and up to the annual allocation
volume in any given year for licences in the NSW Barwon-Darling.
The Commonwealth Environmental Water Office will continue to implement this decision
through 2013–14 with regular review and investigation of alternatives. Should more beneficial
options be identified for use of particular unregulated holdings they will be assessed and
implemented as appropriate.
Decisions on the use entitlements on the NSW Warrego River, where there is a degree of
flexibility in use, will be based on assessment and conditions at the time that a trigger flow
potentially occurs.
The Office will assess seasonal streamflow forecasts and conditions over the course of the year
to assess resource availability. This assessment, along with up-to-date information on
environmental needs and the operational and management conditions (Section 2), will allow
the watering options in Section 5 to be refined for implementation as required.
15
5. Water use options and the Basin Plan’s
environmental watering objectives
5.1.
Demonstrating how Commonwealth environmental water in 2013-14 will
contribute to the Basin Plan’s Environmental Watering Plan objectives –
Northern Unregulated Rivers
Commonwealth environmental water use options in the Northern Unregulated Rivers in 2013-14
include the following four flow types:

baseflows

freshes

bankfull

overbank.
These flow types are illustrated in Figure 3 of the document Commonwealth environmental
water use options 2013-14: Planning approach.
In valleys where the Commonwealth has entitlements that are triggered during high flows,
wetlands and floodplains could also be expected to be inundated by unregulated flows that
include a component of Commonwealth environmental water.
The Commonwealth Environmental Water Office (the Office) has used the best available
science to determine how the expected outcomes of Commonwealth environmental water
contribute towards the objectives of the Basin Plan’s environmental watering plan.
16
Table 4: Expected outcomes from the use of Commonwealth environmental water in the
Northern Unregulated Rivers.
Flow Type
Expected outcomes
for 2013-14
Contributions to
longer term outcomes
Contribution to the
following Basin Plan
objective
Base flows and
freshes
Refuge
Recovery
Resilience
Salinity
pH
Dissolved organic
carbon
Dissolved oxygen
Chemical
Water quality
Freshes and bankfull
Fish reproduction
Fish condition
Landscape fish
diversity
Biodiversity
Freshes, bankfull and
overbank
Waterbird survival
and condition
Landscape bird
diversity
Biodiversity
Bank full and
overbank
Vegetation condition
and reproduction
Landscape
vegetation diversity
Biodiversity
Overbank
Dissolved organic
carbon
Chemical
Water quality
All flow types
Within ecosystem
diversity
Landscape
ecosystem diversity
Biodiversity
Hydrological
connectivity
Connectivity
Ecosystem function
Biotic dispersal
End of system flows
Primary production
Nutrient and carbon
cycling
Resistance
Population resilience
17
Resilience
6. Water use options for 2013-14
6.1.
Watering options
Potential watering options for 2013–14 have been developed for the Warrego River at Toorale
National Park/State Conservation Area which reflect the approach to supply Commonwealth
environmental water to contribute to the overall environmental objectives under the Basin
Plan’s environmental watering plan.
Broadly, the aim of Commonwealth environmental watering in the Warrego River catchment
during 2013–14 will be to support the on-going environmental recovery that commenced
following the breaking of the drought (Section 2). This will mean contributing to river flows to
support fauna recruitment in the Lower Warrego River at Toorale National Park/State
Conservation Area, the riparian zone and on floodplains, particularly the Western Floodplain of
the Toorale National Park/State Conservation Area.
Environmental watering actions for the Barwon-Darling and Queensland unregulated
entitlements will continue in accordance with the Commonwealth Environmental Water Holder
decision of late 2012. Environmental water will remain in-stream to support all flow components
(baseflows, freshes, bankfull and overbank) and contribute to increased flow variability.
Water will be accounted at all available opportunities as suitable flow events occur during the
year. A consideration in developing options for 2013–14 is whether to utilise (ie account for instream and/or overbank contributions) unregulated entitlements or defer take and use
carryover to maximise volumes able to be shepherded in future years when permanent
arrangements will be implemented. These considerations are further described in Section 2.2.
Any water volumes described in the tables below are approximations only. The final volume of
Commonwealth environmental water will depend on river conditions at the time.
The water use options identified do not represent a commitment for use, nor do they reflect all
the possible water use options available. Additional water use options may be identified
throughout the water year. The Office welcomes information from the community on how
environmental water can best be used and managed. If you have any comments or
suggestions, please call 1800 218 478 or send an email to: ewater@environment.gov.au.
18
Option 1 – Lower Warrego-and Darling River in-stream flows
Catchment: Warrego and Darling
Complex: Warrego catchment river flows, Darling catchment river flows
Site:
In-channel assets of the lower Warrego River (Toorale National Park/State
Conservation Area) and Darling River below the junction with the Warrego
Applicable level(s) of resource availability: All inflow scenarios (actual will depend on total
flows during 2013–14)
Relevant flow component:
Expected inundation extent:
Baseflows
Floodplain inundation
Fresh
Wetland inundation
Bankfull flows
Overbank flows
Summary of watering option:

The purpose of the option is to maximise hydrological connectivity of in-stream fresh flows
through the lowest reaches of the Warrego River and to the Darling River by opening gates
in Boera Dam and other downstream storages on the Warrego River at Toorale station. This
will allow the passage of flows derived from the Commonwealth’s river diversion licences
on the Warrego River at Toorale.

The option will enhance longitudinal hydrological connectivity in the lower Warrego and
between the Warrego and Darling Rivers, end of system flows, and the diversity of aquatic
habitat and primary production in these river reaches. It is also expected to provide
opportunities for dispersal of aquatic biota.

The option will also maximise inflows from the Warrego into the Darling River, which
together with planned environmental water and inflows from upstream sources of held
environmental water, will contribute to similar ecological outcomes as in the Warrego.

The option will be undertaken in response to the first appropriate trigger flows in the season.
Timing
2013–14 subject to trigger flows
Volume of Commonwealth
environmental water
Up to 16.2 GL (actual volume will depend on trigger flows)
Operational considerations and feasibility:

This option may commence following a ‘fresh’ flow in the lower Warrego River. A flow of
100-300 ML/day at Ford’s Bridge, approximately 30 km upstream, is indicative of a fresh at
Toorale.

Commonwealth environmental water will be passed by opening/re-opening gates in Boera
Dam, the most upstream storage on the Warrego, and at downstream structures once the
flow has established.

Infrastructure will be operated by NSW Parks and Wildlife (site managers) to deliver the
required flows. This will be undertaken in consultation with the CEWO with the following key
considerations:
o
o

The rate of gate opening will be matched to inflows to Boera Dam, to maintain
water levels, to protect in-stream and pool fauna and prevent erosion, up to the
maximum capacity of the gates (600 ML/day)
Passing of flows will be managed to ensure that the water level in Boera Dam at
the conclusion of the option is sufficient to maintain the refuge value of the weir
pool for aquatic biota, for example, if a long dry period ensues.
Up to 16.2 GL from the Warrego river diversion licences (two times the 2013-14 allocation
and the maximum that can be used in any year) is proposed to be used.
19
Option 2 – Toorale Western Floodplain flows
Catchment: Warrego and Darling
Complex: Other Warrego catchment sites
Site: Warrego River Western Floodplain at Toorale National Park/State Conservation Area
Applicable level(s) of resource availability: Trigger flows could occur under any scenario but
are more likely with very high and high annual inflows.
Relevant flow component:
Expected inundation extent:
Baseflows
Floodplain inundation
Fresh
Wetland inundation
Bankfull flows
Overbank flows
Summary of watering option:

Provide overbank flows to the Warrego River Western Floodplain by operating infrastructure
on Boera Dam to bias delivery of river flows to this area. Potential outcomes of inundation of
the floodplain are to:
o
Support the condition and reproduction of floodplain and semi-permanent wetland
vegetation communities on the Western Floodplain, including areas of the Endangered
Ecological Community Coolibah Black Box Woodland of the Darling Riverine Plains, river
cooba and areas of lignum shrub land
o
Support waterbird survival and condition and contribute to recruitment opportunities
for waterbirds, including the brolga listed as a vulnerable species in NSW and other
aquatic species that inhabit the Western Floodplain when flooded
o
Provide dispersal opportunities for aquatic biota, including native fish, for which the
floodplain may provide a nursery area under some conditions.
Timing
2013–14 subject to trigger flows
Volume of
Commonwealth
environmental water
Up to 9.7 GL (actual volume will depend on trigger flows/access
opportunities)
Operational considerations and feasibility:

This option may commence following a fresh flow in the Warrego River, based on gauged
flows at Ford’s Bridge, 30 km upstream of Toorale station, which is projected to exceed the
capacity of the Boera Dam outlet.

The option could be undertaken during the same flow event in which water is provided for
in-stream use (Option 1), or in a subsequent event depending on trigger flows and the
practicality of operating the gates at Boera Dam.

Once the fresh flow has reached the Darling River Commonwealth environmental water will
be provided to the Western Floodplain by closing the gates in Boera Dam, spilling inflows to
over the western bank (bywash) of the dam and onto the floodplain.

Infrastructure will be operated by NSW Parks and Wildlife Service (site managers) to deliver
the required flows.

The method to account for Commonwealth environmental water flows to the Western
Floodplain will be developed jointly with the NSW Office of Environment and Heritage. This
will be based on upstream gauged flow data at Ford’s Bridge taking into account: losses,
gauged water levels on Boera Dam, known release rates from in-stream structures on the
Warrego River and estimated rates of outflow from Boera Dam via the eastern and western
breakouts.
20
Barwon Darling in-stream flows – As per the Commonwealth Environmental Water Holder
decision of late 2012.
Catchment: Barwon-Darling
Complex: Barwon-Darling catchment river flows
Site: Depends on actual flows and may include fringing wetlands and in-channel assets
Applicable level(s) of resource availability: All (actual will depend on total flows during 2013–
14)
Relevant flow component:
Expected inundation extent:
Baseflows
Floodplain inundation
Fresh
Wetland inundation
Bankfull flows
Overbank flows (limited)
Summary of watering option:

Water that becomes available from the Commonwealth’s unregulated holdings in the
Barwon-Darling River will be left in-stream to support natural river flows (baseflows, freshes,
bankfull and overbank component) and contribute to a more naturally variable flow
regime in this system to improve the resistance of aquatic biota and the resilience of the
system.

Together with planned environmental water and inflows from sources of held environmental
water in tributary streams, the additional in-stream water will contribute to meeting flow
requirements for the Barwon-Darling River channel.

Commonwealth environmental water will support key ecosystem functions associated with
the type of flows (ie flow components) that occur during 2013–14. The water could
contribute to potential outcomes such as:
o
Baseflows: re-establish hydrological connectivity; maintain waterhole refuges in the
Barwon-Darling main channel; and facilitate dispersal of aquatic biota
o
Freshes: maintain water quantity and quality in drought refuge pools; facilitate fish
migration and reproduction; provide diversity of in-stream habitats; and contribute to
carbon and nutrient cycling
o
Bankfull flows: maintain the condition of and support reproduction of riparian
vegetation and permanent and semi-permanent wetland vegetation close to the
main river channel and in billabongs, anabranch/floodrunners, distributary systems fed
by flows in the main river channel (eg Talyawalka Anabranch and many other smaller
systems); and maintain condition and reproduction of native fish
o
Overbank flows: provide hydrological connectivity to disconnected wetlands and
floodplains (including filling overflow lakes in the Talyawalka Anabranch system);
maintain condition and reproduction of floodplain vegetation communities; and
provide carbon/nutrient inputs to support in-stream primary production. Note that the
inundation of high level floodplain vegetation such as black box woodland and
native grassland in the Barwon-Darling, or inundation to significantly fill
anabranch/effluent systems, requires large unregulated flow events which are not
greatly influenced by the relatively small additional volumes of environmental water
present in the system during overbank flow conditions.
Timing
2013–14 subject to trigger flows
Volume of
Commonwealth
environmental water
Up to 25.6 GL (expected 2013–14 allocation to Commonwealth
licences)
21
Operational considerations and feasibility:

Water will be ‘taken’ (accounted as in-stream flow) against individual entitlements until the
annual allocation for 2013–14, expected to be 25.6 GL for holdings as at end of March 2013,
is exhausted.

Accounted take will commence when flow thresholds are met for each flow access class
(A, B, C class access licences) at the first opportunity in the water year and thereafter at all
available opportunities until the maximum proposed volumes are exhausted.

During access periods volumes will be accounted at the individual daily extraction limit
(IDEL) specified in licence conditions for each flow access class.

Rainfall and stream flows in the Barwon-Darling and tributary catchments will be tracked
during the year by the Commonwealth Environmental Water Office using online stream flow
and climate data.

The Office will monitor all flow events in the system (Mungindi to Menindee) during the year
and will compare these to previous events and the historical or modelled flow record.

The magnitude and nature of the change to flow hydrographs as a result of the additional
environmental water in the system from entitlements in the Barwon-Darling and tributary
streams, and potential ecological benefits, will be determined through the hydrological
assessment.
22
Queensland Murray-Darling streams in-stream flows – As per the Commonwealth
Environmental Water Holder decision of late 2012.
Catchments: Moonie, Border Rivers, Condamine-Balonne, Nebine Creek and Warrego River
Complex/Sites: Will depend on unregulated flow conditions in 2013–14 but may include:
Catchment
Complex/Site
Flow component
Border Rivers
Border Rivers catchment flows
All
 Severn River in Sundown National Park (Qld)
 Lower Macintyre River in-stream flows
All
Fresh, bankfull, overbank
Other Border catchment sites
Baseflow, fresh, bankfull
 Refugial waterholes in Severn River and Sundown
National Park
Moonie
Nebine Creek
Moonie catchment river flows
All
Other catchment sites/Lower Moonie floodplain
wetlands (below Nindigully)
Overbank
Nebine Creek catchment river flows
All
Other Nebine catchment sites
Overbank
 Lower Nebine (western)
 Culgoa River floodplain
CondamineBalonne
Lower Balonne catchment river flows
Baseflow to bankfull
 Distributary channels flows
All
Lower Balonne
Other catchment sites
Warrego – Qld
 Lower Balonne River Floodplain system
Bankfull, overbank
 Culgoa River floodplain
Overbank
 Narran Lakes
All
 Refugial waterholes in distributary channels
Low to bankfull
Warrego catchment river flows
All
Other Warrego Catchment sites
Baseflow to bankfull
Upper  Warrego River waterholes
Lower  Warrego River Distributary System
Bankfull, overbank
Lower  Yantabulla Swamp (Cuttaburra Basin)
Bankfull, overbank
Applicable level(s) of resource availability: Trigger flows could occur in any inflow scenario
Relevant flow component:
Expected inundation extent:
Baseflows
Floodplain inundation
Fresh
Wetland inundation
Bank-full flows
Over-bank flows
Summary of watering option:

Water that becomes available from the Commonwealth’s unregulated holdings will be left
in-stream to support natural river flows (baseflows, freshes, bankfull and overbank) and
contribute to a more naturally variable flow regime in the Queensland Murray-Darling Basin
streams to improve the resistance of aquatic biota and the resilience of the system.

In-stream use will contribute to meeting the environmental flow requirements for the Lower
Balonne River Floodplain and Narran Lakes, and for in-channel flows in the Barwon-Darling
River. End of system flows for several systems are expected to be improved.

The additional Commonwealth environmental water will depend on the flow component
23
and could contribute to potential outcomes such as:
o
Baseflows: re-establish hydrological connectivity in ephemeral streams and maintain
refuges (waterholes) in the main river channel and distributary channels, such as the
Cuttaburra Basin-Yantabulla Swamp in the Warrego catchment, and distributaries of the
lower Balonne system; and facilitate dispersal of aquatic biota
o
Freshes: maintain water quantity and quality in drought refuge pools (eg Lower Balonne
distributaries); facilitate fish migration and reproduction; provide diversity of in-stream
habitat; and contribute to carbon and nutrient cycling
o
Bankfull events: maintain condition and support reproduction of riparian vegetation and
permanent and semi–permanent wetland vegetation close to major rivers and
distributary channels; maintain fish condition and provide for native fish reproduction;
provide diversity of in-stream habitats; and contribute to carbon and nutrient cycling
o
Overbank flows: maintain hydrological connectivity to disconnected wetlands and
floodplains, for example, Culgoa River floodplain within the NSW and Queensland
national parks; maintain condition and reproduction of floodplain vegetation
communities; provide carbon/nutrient inputs to support in-stream primary production.
Note that inundation of high level floodplain vegetation such as black box woodland
and native grassland requires medium to large unregulated flow events which, with the
possible exception of the Culgoa River floodplain in the Lower Balonne, are not greatly
influenced by the relatively small additional volumes of environmental water present in
the system during overbank flow conditions
o
Freshes, bankfull and overbank flows contribute inflows to terminal wetland systems
including the Narran Lakes and the Cuttaburra Basin. Subject to sufficient total
event/season volumes and timing these inflows could be expected to support waterbird
condition, survival and reproduction at these sites.
Timing
2013–14 subject to trigger flows
Volume of Commonwealth
environmental water
Up to 100.5 GL (for Commonwealth holdings as at end March
2013)
Actual volume will depend on trigger flows
Operational considerations and feasibility:

Water will be ‘taken’ (accounted as in-stream flow) against individual entitlements until:
o
Annual use limits are exhausted for entitlements in the Warrego (16.1 GL), Moonie
(1.4 GL), Nebine Creek (5.9 GL) and Border Rivers main stem (4.9 GL)
o
The multi-year account balances for entitlements in the Lower Balonne (up to 71.2 GL for
holdings as at the end of March 2013) are exhausted
o
The remainder of the (three-year) volumetric limit, considering use in the previous two
years (irrigation season only: October to February) for the entitlement in the Severn River
(1.023 GL) is exhausted.

Take will occur at the first opportunity in the water year when access to the entitlement is
triggered and thereafter at all available opportunities when triggers are met.

Take will commence when individual flow conditions are met (Moonie, Nebine Creek, Severn
River in the upper Border Rivers) or in accordance with periods of announced access (Lower
Balonne, Border Rivers main stem, Warrego).

During access periods take will be at the maximum daily rate specified in entitlement
conditions.

Accounting for in-stream use will be undertaken by the Office using operational stream flow
data from Queensland and NSW agency websites.

The Office will monitor all flow events in the Queensland streams during the year and will
compare these to previous events and the historical or modelled flow record.

The magnitude and nature of the change to flow hydrographs as a result of the additional
environmental water in the system from Commonwealth entitlements, and potential
ecological benefits, will be determined through the hydrological assessment.
24
6.2. Assessment of environmental watering options
The proposed watering options will be assessed closer to the proposed timing for delivery using
the criteria for assessing environmental watering actions. This assessment will form part of the
Commonwealth Environmental Water Office’s assessment of seasonal, operational and
management considerations and will inform a recommendation to the Commonwealth
Environmental Water Holder to approve water use. A description of these criteria is provided in
the Framework for Determining Commonwealth Environmental Water Use which is available at:
www.environment.gov.au/water/publications/action/pubs/cehw-framework.pdf.
This assessment will include a comprehensive risk assessment which is subject to the prevailing
valley and river flow conditions and will consider proposed costs, delivery, monitoring and
accounting arrangements and potential third party impacts. Any additional watering options
identified during the course of the year will also be subject to an assessment against the
criteria.
25
7. Accounting for the use of Commonwealth
environmental water
7.1.
Water use accounting
Accounting for in-stream use (at the point of take) will be undertaken by the Office in
accordance with all licence conditions using operational stream flow data from Queensland
and NSW agency websites and any relevant agency notices or water harvesting
announcements.
Volumes of water taken for in-stream use will be accounted at the reference location
(gauging station) specified in the entitlement conditions or the nearest gauging station where
no reference point is specified.
Estimates of use will be updated weekly. End of water year use estimates will be provided to
agencies for review and verification prior to finalising.
7.2.
Operational monitoring
Rainfall and stream flows in the Northern Unregulated Rivers (Qld and NSW) will be tracked
during the year by the Office using online stream flow and climate data.
The Office may undertake an assessment of flow events to determine hydrologic outcomes of
Commonwealth environmental water use and identify potential ecological outcomes.
The key part of this assessment will be to characterise the flow events to which Commonwealth
environmental water has contributed. This includes details such as peak and total event flows,
the flow component (baseflow, fresh, bankfull and overbank) and whether ecologically
significant flow thresholds may have been met. Consideration of flow indicators identified by
the Murray–Darling Basin Authority for relevant hydrologic indicator sites are also included
(MDBA 2011). Thresholds identified for other regionally important environmental assets (eg
commence to flow levels and filling flow volumes for distributary/anabranch/wetland systems;
or flows required to reconnect waterholes after dry periods) may also be considered in
assessing unregulated flows in other parts of the region.
The second part of the assessment will estimate the increase in environmental flows due to the
additional Commonwealth environmental water in the system. This will involve comparing
actual flow hydrographs to predicted flows had the Commonwealth environmental water
been extracted.
Hydrological assessments will be carried out during the year at the conclusion of flow events
and at the end of the year for water-year reporting purposes.
26
8. Partnerships
The Office has provided information to a range of stakeholders and invited their feedback
about proposed Commonwealth environmental water use options for the Northern
Unregulated Rivers for 2013–14. These include:

AgForce Queensland

Australian Conservation Council

Australian Floodplain Association

Barwon Darling Water

Cotton Australia

Darling River Action Group

Environmental Farmers Network

Environmental Water Scientific Advisory Panel

Inland Rivers Network

Murray-Darling Basin Authority

National Irrigators' Council

Nature Conservation Council of New South Wales

New South Wales Department of Primary Industry

New South Wales Office of Environment and Heritage

New South Wales Office of Water

Northern Basin Aboriginal Nations

Northern Borders Advisory Council

Queensland Conservation

Queensland Department of Environment and Heritage Protection

Queensland Department of Natural Resources and Mines

Queensland Fisheries

Queensland Murray Darling Committee

South West Natural Resource Management Ltd

Western Catchment Management Authority
The Office will continue to work with stakeholders and other interested community members in
the planning, delivery, management and monitoring of Commonwealth environmental water.
27
9. Bibliography
Bureau of Meteorology Record Breaking La Niña, 2012.
Capon S (2009) Flow-dependent Ecosystems of Toorale Station: Ecological character,
condition and issues associated with decommissioning water resources infrastructure,
Australian Rivers Institute, Griffith University, Australia. Internal report for Dept Environment,
Water, Heritage and the Arts.
Davies PE, Stewardson MJ, Hillman TJ, Roberts JR and Thoms MC 2012, Sustainable Rivers
Audit 2: The ecological health of rivers in the Murray–Darling Basin at the end of the Millennium
Drought (2008–2010). Volume 1. The Independent Sustainable Rivers Audit Group for the
Murray–Darling Basin (ISRAG). MDBA Publication No. 72/12.
MDBA (2011) The proposed "environmentally sustainable level of take" for surface water of the
Murray–Darling Basin: Method and Outcomes, Murray Darling Basin Authority. November 2011.
MDBA (2012a) Assessment of environmental water requirements for the proposed Basin Plan:
Lower Balonne Floodplain. MDBA Publication No: 24/12. Murray Darling Basin Authority,
Canberra.
MDBA (2012b) Assessment of environmental water requirements for the proposed Basin Plan:
Narran Lakes. MDBA Publication No: 27/12. Murray Darling Basin Authority, Canberra.
MDBA (2012c) Assessment of environmental water requirements for the proposed Basin Plan:
Barwon-Darling River upstream of Menindee Lakes. MDBA Publication No: 41/12 Murray Darling
Basin Authority, Canberra.
NSW Primary Industries (2012) Water shepherding option and issues analysis report. Water
shepherding in NSW – Advice to the Water Shepherding Taskforce. NSW Office of Water. May
2012.
28