Commonwealth environmental water use options 2013

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Commonwealth environmental
water use options 2013-14:
Border Rivers
1
Cover image credit: Severn River, Kwiambal National Park, Border Rivers. Photo by Clare d’Arcy
© 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: Border 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
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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
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Commonwealth environmental water use options
2013-14: Border Rivers
Table of contents
1. Introduction ........................................................................................................ 5
2. Context for water use in 2013–14 in the Border Rivers .................................... 6
2.1.
Delivering environmental water to the Border Rivers ......................................................... 6
2.2.
Operational and management considerations for 2013–14 in the Border Rivers ......... 8
2.3.
Valley condition ....................................................................................................................... 10
3. Water availability ............................................................................................. 11
3.1.
Commonwealth environmental water holdings in the Border Rivers for 2013–14 ...... 11
3.2.
Other sources of environmental water allocations .......................................................... 11
3.3.
Natural or unregulated flows and planned environmental water ................................ 11
4. Planning for water use in the Border Rivers in 2013-14 ................................. 14
4.1.
Planning for a range of inflows in 2013-14 .......................................................................... 14
4.2.
Implementing watering actions throughout the year ...................................................... 14
5. Water use options and the Basin Plan’s environmental watering plan
objectives ......................................................................................................... 15
5.1.
Demonstrating how Commonwealth environmental water in 2013–14 will contribute to
the Basin Plan’s Environmental Watering Plan objectives – Border Rivers.................... 15
6. Water use options for 2013–14 ........................................................................ 16
6.1.
Watering options...................................................................................................................... 16
6.2.
Assessment of environmental watering options ................................................................ 21
7. Accounting for the use of Commonwealth environmental water .............. 23
7.1.
Water use accounting ............................................................................................................ 23
7.2.
Operational monitoring .......................................................................................................... 23
8. Partnerships ...................................................................................................... 24
9. Bibliography ..................................................................................................... 25
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List of Figures
Figure 1: Map of the Border Rivers .............................................................................................................. 7
Figure 2: How inflows may vary and impact on water resource availability over the course of
2013–14 in the Border Rivers, from a starting point of Moderate to High resource availability. ... 14
List of Tables
Table 1: Operational considerations for the Border River Valley in 2013–14. ..................................... 9
Table 2: Commonwealth environmental water holdings in the Border Rivers as at 30 April 2013.
......................................................................................................................................................................... 11
Table 3: Other potential sources of environmental water in the Border Rivers catchment for
2013–14. .......................................................................................................................................................... 12
Table 4: Expected outcomes from the use of Commonwealth environmental water in the
Border Rivers. ................................................................................................................................................. 15
Table 5: Potential watering options for 2013–14 for the Border River valley. .................................... 17
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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 Border 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 catchment and across the Murray-Darling Basin and having regard to
the Murray-Darling Basin Authority’s Basin annual environmental watering priorities, once
published.
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2. Context for water use in 2013–14 in the
Border Rivers
2.1.
Delivering environmental water to the Border Rivers
The Border Rivers is based around the Macintyre River and the Dumaresq River, which merge
upstream of Boggabilla and continue as the Macintyre River. The Macintyre River ultimately
becomes the Barwon River. The Macintyre River's main tributary is the NSW Severn River. The
principal tributaries of the Dumaresq River are the Beardy River and Ottley's Creek.
Below Goondiwindi, effluent creeks and anabranches break off the Macintyre River channel
and form a meandering complex of billabongs and wetlands across an extensive floodplain.
These breakouts include Callandoon and Dingo Creeks in Queensland and Whalan Creek and
Boomi River in NSW. The most significant tributary in the floodplain zone is the Weir River
(Queensland). Below the confluence of the Weir and Macintyre Rivers, the main stream
becomes the Barwon River.
Collectively, public storages providing regulated supplies have a capacity of 635 GL,
comprising Pindari Dam on the Severn River in NSW (312 GL), Glenlyon Dam on Pike Creek in
Queensland (254 GL) and Coolmunda Dam on Macintyre Brook in Queensland (69 GL). The
volume of on-farm storage is comparable to public storage, reflecting the importance of
unregulated flows (diversion of river and overland flows) to irrigation supplies in the catchment.
On average, the majority of water use in the Border Rivers catchment is based on opportunistic
access to unregulated flows (supplementary water access in NSW and unsupplemented water
allocations in Queensland). Regulated water entitlements (supplemented water allocations in
Queensland, high and general security licences in NSW) comprise a smaller component of
overall water use.
Environmental water demand in the Border Rivers includes baseflow and in-channel fresh
requirements. Baseflows target habitat availability, nutrient cycling, fish passage, and riparian
health outcomes, and are limited to in-channel flows which can be satisfied through relatively
low release rates from dams. In-channel fresh events aim to improve nutrient cycling, facilitate
the migration and recruitment of native fish species, and enhance anabranch connection and
riverine woodlands. Regulated releases from storages can be timed to coincide with
unregulated flows in order to contribute to in-channel fresh requirements. Where possible,
environmental water will be managed to benefit multiple sites en route to maximise the
efficiency and effectiveness of water use.
The Commonwealth’s unregulated flow access entitlements cannot be actively ‘delivered’
and are left in-stream during unregulated flow conditions. This augments unregulated water
already protected from extraction in the system and contributes to local and downstream flow
benefits. The extent of how far benefits flow through the system depends on the circumstances
for individual flow events. Benefits may extend downstream to the Barwon–Darling.
Figure 1 below shows a map of the Border Rivers.
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Figure 1: Map of the Border Rivers (CSIRO 2007).
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2.2.
Operational and management considerations for 2013–14 in the Border
Rivers
The achievement of desired environmental outcomes will be closely related to the careful
coordination of the timing of environmental water releases to coincide with unregulated flows
in the Border Rivers. Regulated releases (including irrigation orders, stock and domestic
replenishment flows or NSW stimulus flow) also offer opportunities to “piggy back”
Commonwealth environmental water and increase the potential for environmental objectives
to be achieved and assist with delivery efficiency.
In 2012-13, river operators in the NSW and QLD developed a draft framework to manage the
delivery of QLD allocation from the NSW Pindari Dam. On a trial basis, 626 ML of
Commonwealth QLD allocation was successfully delivered in accordance with this framework
without any impacts on other licence holder’s water availability or reliability. Applications to
trial the delivery of water under this proposed framework are considered by the state resource
operators on a case by case basis.
Operational considerations such as delivery methods, opportunities, constraints and risks will
differ depending on the inflow scenario and are summarised in Table 1. Operational
considerations are assessed against inflow scenarios which are represented by annual
exceedance probability (AEP), that is, the number of years that a given inflow volume is
equalled or exceeded, expressed as a percentage.
Throughout the year operational and management considerations will be addressed as
decisions are taken to make water available for use and as these decisions are implemented.
This will include refining the ecological objectives, assessing operational feasibility and
potential risks and the ongoing monitoring of the seasonal outlook and river conditions.
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Table 1: Operational considerations for the Border River Valley in 2013–14.
Inflow scenario
Very low
(90%
AEP1)
Low
(75%
AEP)
Moderate
(50% AEP)
High
(25%
AEP)
Very high
(10%
AEP)
Opportunities
Manage the recession of unregulated
flows to provide for a more natural flow
pattern.
Use environmental water in conjunction
with, or to maximise the environmental
benefit of, unregulated river flows.
Use environmental water in conjunction
with, or to maximise the environmental
benefit of, other water orders.
Accrediting and shepherding of flows
once they enter Barwon Darling system
(once agreed arrangements are in place).
Constraints
Natural flows meet environmental flow
requirements, reducing the need for and
effectiveness of the release of
environmental water.
Delivery options are limited due to high
unregulated flows resulting in reduced
channel capacity, limiting the operation of
river infrastructure and inhibiting additional
releases from storages.
Maximum annual usage on current
regulated entitlements is 0.3 GL (NSW) and
11.7 GL (Queensland) and 5.9 GL
unregulated flow access entitlements2.
Flow thresholds for existing river
infrastructure may constrain the delivery of
environmental water.
Risks*
Percentages refer to the probability of exceedance based on historical inflows for the valley,
i.e. there is a 90 per cent chance that actual flows will be greater than that amount.
1
Based on holdings as at 30 April 2013, please note that Queensland Border Rivers (Medium)
entitlements have an 85% account limit at any one time.
2
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Inflow scenario
Very low
(90%
AEP1)
Low
(75%
AEP)
Moderate
(50% AEP)
High
(25%
AEP)
Very high
(10%
AEP)
The provision of Commonwealth
environmental water must consider
potential inundation impacts to property
and infrastructure.
*See Section 6.2 for more information on risk management.
2.3.
Valley condition
Between 2002 and 2010 the Border Rivers catchment received low inflows due to a long period
of drought, which coupled with river regulation, had a significant effect on the environmental
condition of the valley. The MDBA released its second Sustainable Rivers Audit report in 2012
(based on data collected from 2008 to 2010) and concluded that the Border Rivers valley was
in poor river ecosystem health. While the Border Rivers valley was recognised as having good
hydrology with moderate physical form, fish and macroinvertebrate communities, the valley
was rated as poor for riparian vegetation communities (MDBA 2012b).
Some moderate inflows occurred during this period in 2003–04, but drought-breaking inflows
were experienced in 2010–11 with further high inflows experienced across the valley in 2011–12.
Consecutive years of widespread flooding and overbank flows have provided significant
longitudinal and lateral connection of river channel and fringing wetlands. This would have
provided breeding and recruitment opportunities for a range of native aquatic species and an
improvement in their condition.
The 2012–13 water year returned to drier than average conditions in the Border River valley. To
late January 2013, rainfall was very much below average across the entire valley, while above
average temperatures were experienced particularly throughout summer. These conditions
resulted in high system demand (irrigation orders) in the catchment. Unregulated flow events in
February and March 2013, peaking at 30,000 ML/day at Mungindi in early February 2013,
transmitted nutrients and carbon inputs to the river, drowned out weirs, inundated benches
and riparian vegetation and connected fringing wetlands and lagoons along the length of the
Macintyre River.
In December 2012, 0.9 GL of Commonwealth environmental water was delivered in
combination with a NSW stimulus flow (refer Section 3.3) and irrigation orders. Early monitoring
indicates the stimulus achieved its objectives to: disturb and reset algal communities, stimulate
production through all levels of the aquatic food chain, inundate riparian areas and provide
aquatic species access to a diversity of aquatic habitats to feed and shelter.
Improvements to threatened species and vegetation regeneration resulting from consecutive
years of unregulated events will require support in the coming water years to ensure their
survival and to continue to improve their condition.
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3. Water availability
3.1.
Commonwealth environmental water holdings in the Border Rivers for
2013–14
Commonwealth environmental water holdings available for use in 2013–14 in the Border Rivers
are shown in Table 2 below.
Table 2: Commonwealth environmental water holdings in the Border Rivers as at 30 April 2013.
Entitlement type
Entitlement held
(GL)
Long-term
average annual
yield (GL)
Carryover from
2012–13 (GL)1
Forecast water
availability for
2013–14 (GL)
NSW Border Rivers
(General B)
0.3
0.1
0
0.1-0.2
Qld Border Rivers
(Medium)
11.5
3.8
8.3
11.5
Qld Macintyre
Brook (General B)
0.2
0.2
0.4
0.4
Border Rivers –
Severn
(Unsupplemented)
1.3
0.5
N/A
Up to 1.0
Border Rivers Macintyre
(Unsupplemented)
3.3
1.3
N/A
Up to 4.9
Total
16.2
5.9
8.7
~12
(0.2 available
within use limits.)
Notes:
1. Future decisions about use, transfers and the ability to deliver already approved actions
will affect expected carryover from 2012-13.
2. The forecast for unregulated water is to receive up to the maximum allowed use, subject
to the announcement of trigger flows. Forecasts are based on the best available
information including State forecasts and historical inflow scenarios. Forecasts include
carryover from 2012-13. Forecasts for are given to the nearest whole gigalitre for
regulated entitlements. Forecast total is exclusive of unregulated water.
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. A
portfolio management statement for the Border Rivers is available at
http://www.environment.gov.au/ewater/publications/index.html.
3.2.
Other sources of environmental water allocations
There are currently no other sources of held environmental water in the Border Rivers.
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 natural or unregulated flows and water provided for the environment under
rules in state water plans (referred to as ‘planned environmental water’). Other sources of
environmental water may be available to supplement Commonwealth environmental water
delivery in the catchment during 2013–14 (Table 3). The Bureau of Meteorology provides a
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seasonal streamflow forecasting service, which estimates the potential for low, median or high
flows for the coming three months ahead.
The NSW Border Rivers Water Sharing Plan includes the high conservation value reach of the
Severn (NSW) and Macintyre Rivers downstream of Pindari Dam. The Pindari Dam stimulus flow
and translucency rules (i.e. inflows up to 50 ML/day between September and May are passed
downstream; up to 200 ML/day between June-August) attempts to mitigate the impacts of the
dam on the natural hydrological regime and aquatic ecosystems in the Severn River (NSW).
Commonwealth environmental water would be in addition to these flows and provide
increased benefits to this asset.
NSW and Queensland have water management rules in place for the Macintyre River
downstream of Goondiwindi. These rules aim to provide additional flows to this area. There is
an end of system low flow rule that protects tributary inflows to maintain flows at Mungindi on
the Barwon above 100 ML/day (September–March). When unregulated flow events arise,
announcements are made constraining the times, locations and rates for the take of water
under unregulated flow access entitlements. There are complex rules for determining these
announcements. For example, access to freshes below the junction of the Macintyre River and
the Dumaresq River that arise from inflows above Goondiwindi, does not commence until the
total flow over two consecutive days exceeds 10,000 ML. Access ceases when the total lows
over two consecutive days at Goondiwindi drops below 3,650 ML. In dry to medium years it is
likely that some of these events will be protected in order to meet downstream requirements
for freshes in the Barwon-Darling River (although in very dry years such events are less likely to
occur). Commonwealth environmental water would be in addition to these rules and provide
increased benefits to this asset.
Table 3: Other potential sources of environmental water in the Border Rivers catchment for
2013–14.
Source
Stimulus flow Pindari
Dam
Instrument
Management
Authority
Potential Allocation
NSW Water
Sharing Plan
NSW OEH and
NOW
NSW State
Water
(delivery)
4 GL/year reserved for a
stimulus flow, provided trigger
conditions are achieved. Can
be accrued to a maximum of 8
GL (4 GL available in 2013-14).
NSW State
Water
Up to 0.05 GL/day
(September–May)
Translucency flows
Pindari Dam
Up to 0.2 GL/day (June–
August)
Maximum of 30 GL/year
Improving low flows at
end of system
NSW Water
Sharing Plan
High flow protection
NSW-Queensland
Intergovernmental
Agreement on the
Border Rivers 2008
Low flow allowance
Coolmunda Dam
Queensland
Border Rivers
Resource
Operations Plan
QLD DNRM
NSW State
Water/NOW
Tributary inflows protected to
maintain flow at Mungindi on
the Barwon above 0.1 GL/day
(September–March)
25% of unregulated flows in
main trunk and Macintyre River
in NSW protected from point of
inflow to Mungindi
Queensland
SunWater
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The first 0.1 GL/day of inflows
released to 6 GL/year.
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4. Planning for water use in the Border Rivers
in 2013-14
4.1.
Planning for a range of inflows in 2013-14
In addition to influencing opportunities, constraints and risks in relation to environmental
watering (see Table 1), inflows are a primary driver of resource availability. Resource availability
also reflects a combination of the allocations available to the Commonwealth Environmental
Water Holder (Section 3.1 above) as well as natural or unregulated flows and planned
environmental water (Section 3.3).
Given the variable rainfall experienced across the Basin, inflows are difficult to accurately
forecast. As shown in Table 2, carryover from 2012–13 for the Border Rivers is likely to be
approximately 8.7 GL. Forecast early season allocations (up to 31 July 2013) are likely to be
minimal (as a result of relatively low inflows in autumn 2013 and high carryover account
balance).
Consideration of this allocation range relative to the total entitlement volume (Table 2) and the
full range of inflows that may be possible suggests that resource availability early in 2013–14
may be moderate to high. From this starting point, the full range of possible inflows suggest that
resource availability over the course of the year could be between low and very high, and
unlikely to become very low (Figure 2). As such, the water use options described in Section 6
have been considered for a range of resource availability between low and very high.
Figure 2: How inflows may vary and impact on water resource availability over the course of
2013–14 in the Border Rivers, from a starting point of Moderate to High resource availability.
4.2.
Implementing watering actions throughout the year
Resource availability will change over the course of 2013–14 as new allocation
announcements are made, and water is used or traded. Climatic conditions will also affect the
potential for inflows. The Office will regularly review allocations against environmental
entitlements and seasonal streamflow forecasts 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 6 to be refined for implementation as required.
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5. Water use options and the Basin Plan’s
environmental watering plan objectives
5.1.
Demonstrating how Commonwealth environmental water in 2013–14 will
contribute to the Basin Plan’s Environmental Watering Plan objectives –
Border Rivers
Commonwealth environmental water use options for the Border Rivers in 2013–14 include the
following two flow types:

base flows

freshes, and

overbank.
These flow types are illustrated in Figure 3 of the document Commonwealth environmental
water use options 2013-14: Planning approach.
Wetlands are also expected to be inundated.
The ecological response from delivering Commonwealth environmental water is reflected in
the expected outcomes.
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.
Table 4 shows the expected outcomes that may be derived from Commonwealth
environmental watering using different flow types in the Border Rivers and the relevant Basin
Plan objectives.
Table 4: Expected outcomes from the use of Commonwealth environmental water in the
Border Rivers.
Flow Type
Expected outcomes
for 2013–14
Contributions to
longer term outcomes
Contribution to the
following Basin Plan
objective
Base flows
Dissolved oxygen
Chemical
Water Quality
Base flows and
freshes
Fish reproduction
Landscape fish
diversity
Biodiversity
Connectivity
Ecosystem function
Fish condition
Hydrological
connectivity
Biotic dispersal
Base flows and
overbank
Primary production
Process
Refuge
Recovery
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Resilience
6. Water use options for 2013–14
6.1.
Watering options
Potential watering options for 2013–14 have been developed for the Border Rivers, which
reflect the approach to supply Commonwealth environmental water to contribute to the
overall environmental objectives under the Basin Plan’s environmental watering plan.
These watering options have been designed to specifically enable the adaptation of actions
across several potential inflow scenarios. This provides flexibility for water use to best
complement natural inflows. Options have not been developed for high flow scenarios (and
the relevant resource availability). During high inflows, unregulated flows are likely to meet
ecological objectives and (given the small volume of regulated holdings) there may be limited
need for and effectiveness from deliveries of up to 10.9 GL of Commonwealth environmental
water.
Broadly, the aim of Commonwealth environmental watering in the Border Rivers during 2013–14
will be to support in-stream outcomes, with a focus on the on-going environmental recovery
that commenced following the breaking of the drought (see Section 2.3). Watering actions will
focus on contributing to in-stream objectives, including contributing to low flows and freshes to
maintain in-channel habitat and support the growth and survival of native aquatic species.
Any volumes described in the options tables below are approximations only. The final volume
of Commonwealth environmental water made available will depend on river conditions at the
time of use, other environmental water contributions and in consideration of Basin-wide needs.
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.
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Table 5: Potential watering options for 2013–14 for the Border River valley.
Applicable level(s) of
resource availability
(see Section 4)
Low
Moderate
High
Very High
Option 1 – Border Rivers
Fresh Flow
Contribute to fresh flows to improve the health of in-stream habitat and water
quality and to support native aquatic species by providing improved opportunities
for fish to access breeding habitat and to feed and shelter.
Option unlikely to be
pursued under this
resource availability.
Option 2 – Border Rivers
Base Flow
Contribute to base flows to flush and maintain healthy habitats in river pools and
provide greater access to a range of in-stream habitats and at times of very low
flow, critical habitat.
Option unlikely to be
pursued under this
resource availability.
Option 3 – Border Rivers
Infrastructure assisted
delivery
Contribute to availability of suitable refuge habitat by ensuring the persistence of
pools and contributing to water quality within pools.
Option unlikely to be
pursued under this
resource availability.
Note: Under certain resource availabilities, options may be not pursued for a variety of reasons including that environmental demand may be met by
unregulated flows, the may be limited need for and effectiveness from deliveries of small holdings, and that constraints and/or risks may limit the ability
to deliver environmental water.
17
Option 1 – Border River Fresh Flow
Catchment: Border Rivers
Complex: Border Rivers Catchment River Flows
Site: Severn River/Dumaresq River/Lower Macintyre River (including anabranches)
Applicable level(s) of resource availability: Low to High
Relevant flow component:
Expected inundation extent:
Base flows
Floodplain inundation
Fresh
Wetland inundation
Bank-full flows
Over-bank flows/Terminal Wetland
Summary of watering option:

The purpose of the option is to enhance in-stream flows by contributing to fresh flows. This
will contribute to the health of in-stream habitat and water quality, as well as contribute to
high primary productivity within the Border Rivers. Connecting and extending the wetted
period of floodplain and wetland habitat with the main channel will contribute to nutrient
and food production for the aquatic ecological community.

The provision of Commonwealth environmental water in combination with unregulated
freshes will support native fish condition and reproduction by providing improved
opportunities for fish to access breeding habitat and to feed and shelter. The option has the
potential to benefit large bodied native fish including the EPBC listed Murray cod as well as
small bodied native fish, including threatened species such as the purple spotted gudgeon,
which require access to off-channel habitat to breed and disperse.

To achieve this outcome, regulated Commonwealth environmental water could
supplement:
o
o

an unregulated fresh(s) by increasing the duration with a managed rate of fall to
baseflow rates and/or
NSW stimulus flow releases or other source of water with a release regime designed to
mimic a natural flow pattern downstream of storage,
During unregulated flow conditions, the Commonwealth’s unregulated flow access
entitlements cannot be actively ‘delivered’ and are left in-stream, augmenting planned
environmental water already in the system.
Timing
All year (most likely Spring to Autumn)
Volume of Commonwealth
environmental water
Up to 17.8 GL (including up to 5.9 GL unregulated flow access
entitlement, if access triggered)
Operational considerations and feasibility:

This option would supplement unregulated flow or regulated flow (irrigation supply or
stimulus flow or stock and domestic replenishment flow).

Commonwealth environmental water could complement a decision by NSW Office of
Water to provide up to 4 GL of planned environmental water as a stimulus flow downstream
of Pindari Dam. Release regime from storages will be designed to mimic a natural flow
pattern and use up to the outlet maximum flow capacity for the storage.

Under natural conditions, rain generated fresh flows contribute to high primary productivity
within the Severn River/Dumaresq River/Macintyre River associated with carbon inputs from
runoff and high flows inundating benches and connecting anabranches.
o
Unregulated freshes that exceed 700 ML/day to 4500 ML/day downstream of Kanowna
are likely to improve nutrient and carbon cycling and provide greater availability to
habitat by wetting banks, benches and bars present in the Lower Macintyre River
18
channel.
o
Unregulated freshes that exceed 4,000 ML/day to 9000 ML/day downstream of Mungindi
are likely to provide maximum morphological anabranch diversity in the Lower
Macintyre River.

Depending on the timing of the event certain aquatic species will be advantaged
according to their biological requirements. As conditions develop the flow regime and
objectives targeted will be refined. Native fish species in the Gwydir river system typically
reproduce during spring and summer associated with an increase in flow and
temperatures. Deliveries in winter may provide adult fish opportunities to feed and grow
before they reproduce. Providing flows that access in-channel habitat in September to
October would coincide with the smaller reproduction ‘window’ (water temperature
related) of Murray cod and catfish. Larvae and juveniles of these species have been
recorded in fish surveys in late September-early October in northern Basin valleys. Deliveries
during spring to summer may support larval dispersal and contribute to larval/juvenile fish
growth and survival.

Water orders will be developed in conjunction with NSW State Water Corporation and
Queensland Department of Natural Resources and Mines to ensure operational feasibility
and environmental objectives can be achieved.
19
Option 2 – Border River Base Flow
Catchment: Border Rivers
Complex: Border Rivers Catchment River Flows
Site: Severn River/Dumaresq River/Macintyre Brook/Macintyre River channel
Applicable level(s) of resource availability: Low to High
Relevant flow component:
Expected inundation extent:
Base flows
Floodplain inundation
Fresh
Wetland inundation
Bank-full flows
Over-bank flows/Terminal Wetland
Summary of watering option:

The purpose of the option is to: provide flows to refresh or provide hydrological connectivity
to in-stream habitat; ensure the persistence of pools as refuge; and reduce the risk of
degrading water quality conditions, particularly low dissolved oxygen levels.

The proposed option would maintain habitat diversity and or essential refuge habitat for
aquatic species during periods of low to no flow.

To achieve this outcome, Commonwealth environmental water may contribute to flows up
to 500 ML/day at Mungindi. The precise rate will be determined based on antecedent
conditions and flows through the season.
Timing
All year (most likely late winter to Autumn)
Volume of
Commonwealth
environmental water
Up to 10.9 GL
Operational considerations and feasibility:

This delivery option will be delivered by supplementing other water sources (such as
irrigation deliveries or planned environmental water) to provide longitudinal hydrological
connectivity and extend the duration of access to a range of habitats.

Under a sustained low inflow scenario, Commonwealth environmental water deliveries
could contribute to maintaining natural water levels in pools and flowing water in channel
to keep in-stream habitat wet, maintain safe water quality, and provide drought refuge for
a range of aquatic species. The presence or absence of critical habitat is the key factor
influencing aquatic species condition.

Water orders will be developed in conjunction with river operators to ensure operational
feasibility and environmental objectives can be achieved. Commonwealth environmental
water will be delivered and managed within the normal water delivery arrangements.
20
Option 3 – Border River fringing wetlands
Catchment: Border Rivers
Complex: Other Border Rivers Catchment Sites
Site: Macintyre River fringing wetlands (e.g. Morella Watercourse/Pungbougal/Boobera system)
Applicable level(s) of resource availability: Low to High
Relevant flow component:
Expected inundation extent:
Base flows
Floodplain inundation
Fresh
Wetland inundation
Bank-full flows
Over-bank flows
Summary of watering option:

The purpose of the option is to: provide flows to ensure the persistence of pools as refuge;
contribute to water quality within pools; and maintain the health of riparian vegetation.

Commonwealth environmental water provided to the floodplain lagoons fringing the
Macintyre River (e.g. Morella Watercourse/Pungbougal/Boobera system), would be
pumped from the river as per normal irrigator water ordering practice.

The precise rate will be determined based on antecedent conditions and flows through the
season.
Timing
All year (most likely late winter to Autumn)
Volume of
Commonwealth
environmental water
Up to 3 GL
Operational considerations and feasibility:

Floodplain lagoons of the mid Macintyre River depend on overbank and flooding flows and
local catchment inflows to reconnect and refill. These flows have dimished as a result of
river regulation and the development of irrigated agriculture. Some benefit may be
achieved via pumping to discrete sites.

This option may be in scope under very low to high inflow scenarios as some fringing
wetlands in the Border Rivers are only connected to the main channel during large
unregulated events. Options have not been developed for a very high inflow scenario in
recognition that at these times, large areas of the Border Rivers valley (including the target
sites) would likely be experiencing flooding. The provision of additional environmental water
is not required in these conditions and would likely cause adverse third party impacts.

In some cases access to channels will need to be negotiated with landholders and
agreement for inundation of privately owned wetlands will need to be sought. Some
modifications to works to allow this to occur, and to allow water to appropriately flow
between lagoons, could also be required.

Water orders will be developed in conjunction with river operators to ensure operational
feasibility and environmental objectives can be achieved. Commonwealth environmental
water will be delivered and managed within the normal water delivery arrangements.
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
21
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.
22
7. Accounting for the use of Commonwealth
environmental water
7.1.
Water use accounting
In the Border Rivers the Office is responsible for making arrangements to deliver
Commonwealth environment water with river operators such as State Water Corporation and
Queensland Department of Natural Resource and Mines.
River flows will be accounted for at storages or at downstream flow gauges and will be
reported to the Office by State Water Corporation and Queensland Department of Natural
Resource and Mines. Where applicable, water delivered to individual wetland sites will be
accounted at flow gauges or metered pumps at those sites.
7.2.
Operational monitoring
Operational monitoring helps assess whether water has been delivered as planned [e.g. the
volumes, timing (frequency and duration), and location and flow rates of water delivered] and
can include observations of immediate environmental responses.
This monitoring is mostly undertaken by delivery partners in conjunction with the Office. In the
Border River valley, this includes NSW State Water Corporation, NSW Office of Water and
Queensland Department of Natural Resource and Mines.
Delivery partners provide regular operational monitoring updates to the Office. The operational
monitoring requirements are set out in the Office’s Operational Monitoring template.
Key parameters required through operational monitoring are:

Date of Commonwealth environmental water delivery (commencement and finish)

Point of debit/delivery (both if they are different)

Volume of Commonwealth environmental water delivered (provided on a weekly basis)

Flow rate that water is delivered at (hydrograph of delivery if possible)

Monitoring associated with identified risks.
23
8. Partnerships
The Office has consulted with a range of stakeholders to develop the Commonwealth
environmental water use options for the Border Rivers for 2013–14. These include:

Environmental Water Scientific Advisory Panel

Murray-Darling Basin Authority

New South Wales Office of Water

Queensland Department of Natural Resource and Mines

Queensland Murray Darling Commission

New South Wales Office of Environment and Heritage

New South Wales Department of Primary Industries

Border Rivers Gwydir Catchment Management Authority

NSW State Water Corporation.
The Office will continue to work with stakeholders and other interested community members
(through briefing the State Water Border Rivers Customer Service Committee and the Border
Rivers Environmental Watering Network) in the planning, delivery, management and
monitoring of Commonwealth environmental water.
24
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flow regimes for aquatic biodiversity. Environmental Management 30: 492–507.
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Macintyre Brook. A report to the Queensland Murray‐Darling Committee. QLD Department of
Primary Industries and Fisheries.
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the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia.
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Department of Water and Energy (2009) Water Sharing Plan NSW Border Rivers regulated river
water source: Background document, Department of Water and Energy, Sydney.
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overview: Border Rivers Catchment, NSW Department of Primary Industries, Sydney
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Regulated Rivers: Research & Management, 16: 421–432.
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movements of small and medium-sized fish in the Murray-Darling Basin. Murray Darling Basin
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and the wetland environment.” Wetlands Ecology and Management 7: 25–35.
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communities in the rivers of the Murray Darling Basin. Draft low flow requirements paper version
4 May 2011. NSW DPI Fisheries.
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plain-river exchanges in a semi-arid, anabranching river system. International Association of
Hydrological Sciences 276, 19–26.
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native fish species in floodplain waterholes of a dryland river, the Macintyre River, Australia.
Hydrobiologia 614:19–31.
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fish in floodplain lagoons of an Australian dryland river. Environmental Biology of Fishes 90:1–17.
Murray-Darling Basin Authority (2011) The proposed “environmentally sustainable level of take”
for surface water of the Murray-Darling Basin: Methods and outcomes, MDBA publication no:
226/11, Murray-Darling Basin Authority, Canberra.
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proposed Basin Plan: Lower Border Rivers (in-channel flows). Licensed from the Murray–Darling
Basin Authority, under a Creative Commons Attribution 3.0 Australia Licence.
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Reserve: Draft Plan of Management, NSW National Parks and Wildlife Service, Tenterfield, NSW.
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