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Commonwealth environmental water use options 2014–15:

Gwydir River Valley

Cover image credit: Wandoona Waterhole. Photo: Andy Huxham © CEWO

Acknowledgement of the traditional owners of the Murray-Darling BasinThe 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.

© Copyright Commonwealth of Australia, 2014.

Commonwealth environmental water use options 2014–15: Gwydir River Valley is licensed by the Commonwealth of Australia for use under a Creative Commons By Attribution 3.0 Australia licence with the exception of the Coat of Arms of the Commonwealth of Australia, the logo of the agency responsible for publishing the report, content supplied by third parties, and any images depicting people. For licence conditions see: http://creativecommons.org/licenses/by/3.0/au/

This report should be attributed as ‘Commonwealth environmental water use options 2014–15: Gwydir River Valley, Commonwealth of Australia 2014’.

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 the Environment. 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 2014–15: Gwydir River Valley

Table of contents1. Background..........................................................................5

1.1. Demonstrating how Commonwealth environmental water in 2014–15 will contribute to the Basin Plan’s environmental watering plan objectives – Gwydir River Valley..............................................................................................5

2. Context for water use in 2014–15 in the Gwydir River Valley...82.1. Delivering environmental water to the Gwydir River Valley.................................82.2. Operational and management considerations for 2014–15 in the Gwydir

River Valley..........................................................................................................92.3. Valley condition..................................................................................................11

3. Water availability................................................................133.1. Commonwealth environmental water holdings in the Gwydir River Valley for

2014–15.............................................................................................................133.2. Other sources of environmental water allocations.............................................133.3. Natural or unregulated flows and planned environmental water........................14

4. Planning for water use in the Gwydir River Valley in 2014–15154.1. Planning for a range of inflows in 2014–15.........................................................154.2. Implementing watering actions throughout the year.........................................16

5. Water use options for 2014–15............................................175.1. Summary of watering options............................................................................175.2. Assessment of environmental watering options.................................................195.3. Options contributing to the Basin Annual Environmental Watering Priorities.....29

6. Accounting for the use of Commonwealth environmental water..........................................................................................30

6.1. Water use accounting........................................................................................306.2. Monitoring..........................................................................................................30

6.2.1. Operational monitoring...............................................................................306.2.2. Long term intervention monitoring..............................................................30

7. Next steps – from planning to water delivery........................328. Partnerships.......................................................................349. Bibliography.......................................................................35

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List of FiguresFigure 1: The Gwydir River Valley.........................................................................................9Figure 2: How inflows may vary and impact on water resource availability over the

course of 2014–15 in the Gwydir River Valley, from a starting point of moderate resource availability.............................................................................15

Figure 3: The annual management process for Commonwealth environmental water........33

List of TablesTable 1: Expected outcomes from the use of Commonwealth environmental water in

the Gwydir River Valley..........................................................................................6Table 2: Operational considerations for the Gwydir River Valley in 2014–15......................10Table 3: Commonwealth environmental water holdings in the Gwydir Valley as at 31

May 2014..............................................................................................................13Table 4: Other potential sources of environmental water in the Gwydir Valley for

2014–15 as at 30 April 2014.................................................................................14Table 5: Potential watering options for 2014–15 for the Gwydir River Valley......................18Table 6: 2014–15 Basin annual environmental watering priorities for the Gwydir River

Valley....................................................................................................................29

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1.BackgroundThis document is designed to be read in conjunction with the Commonwealth environmental water use options 2014–15: 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 Gwydir River Valley this water 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.

1.1. Demonstrating how Commonwealth environmental water in 2014–15 will contribute to the Basin Plan’s environmental watering plan objectives – Gwydir River Valley

Commonwealth environmental water use options for the Gwydir River Valley in 2014–15 include the following three flow types:

base flows (low flows)

freshes

overbank flows / terminal wetlands.

These flow types are illustrated in Figure 4 of the document Commonwealth environmental water use options 2014–15: Planning approach.

Commonwealth environmental water delivery within the Gwydir River Valley may be delivered to various parts of the river system including:

wetlands

semi-permanent waterholes

and creeks.

The ecological response from delivering Commonwealth environmental water is reflected in the expected outcomes.

The Office has used the best available information to determine how the expected outcomes of Commonwealth environmental water contribute towards the objectives of the Basin Plan’s environmental watering plan. For further information please refer to The Environmental Water Outcomes Framework at www.environment.gov.au/water/cewo/publications/environmental-water-outcomes-framework.

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http://www.environment.gov.au/water/cewo/publications/environmental-water-outcomes-framework

http://www.environment.gov.au/water/cewo/publications/environmental-water-outcomes-framework

Table 1 shows the linkage between planned flow types and the expected outcomes for the Gwydir River Valley. The table also links the short-term expected outcomes to a long-term contribution to the four Basin Plan objectives at the Basin scale (i.e. biodiversity, ecosystem function, resilience and water quality).

Table 1: Expected outcomes from the use of Commonwealth environmental water in the Gwydir River Valley.

Flow Type Expected outcomes for 2014–15

Contributions to longer term outcomes

Contribution to the following Basin Plan objective

Base flows (low flows) Hydrological connectivity, including end of system flows

Connectivity Ecosystem Function

Individual survival and condition (individual refuges)

Population condition (individual refuges)

Resilience

Individual condition (ecosystem resistance)

Population condition (ecosystem recovery)

Resilience

Management of water quality issues (salinity, dissolved oxygen, pH and dissolved organic carbon)

Chemical Water Quality

Freshes Within ecosystem macroinvertebrate diversity

Macroinvertebrate diversity

Biodiversity

Fish condition Fish diversity BiodiversityFish reproduction, larval growth and survival

Larval and juvenile recruitment

Biodiversity

Hydrological connectivity, including end of system flows


Mobilisation and dispersal of biotic and abiotic materials


Primary production, decomposition, nutrient and carbon cycling

Process Ecosystem Function



Resilience



Resilience



Overbank flows / terminal wetlands

Vegetation condition and reproduction

Vegetation diversity Biodiversity

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Flow Type Expected outcomes for 2014–15

Contributions to longer term outcomes

Contribution to the following Basin Plan objective

Vegetation germination and dispersal

Vegetation growth and survival

Biodiversity

Within ecosystem macroinvertebrate diversity

Macroinvertebrate diversity

Biodiversity

Fish condition Fish diversity BiodiversityFish reproduction, larval growth and survival

Larval and juvenile recruitment

Biodiversity

Waterbird survival and condition

Waterbird diversity and population condition

Biodiversity

Waterbird reproduction, recruitment and fledging

Waterbird diversity and population condition

Biodiversity

Other vertebrate reproduction, growth and survival (frogs)

Adult abundance (frogs)

Biodiversity

Hydrological connectivity, including end of system flows


Mobilisation and dispersal of biotic and abiotic materials


Primary production, decomposition, nutrient and carbon cycling

Process Ecosystem Function



Resilience



Resilience



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2.Context for water use in 2014–15 in the Gwydir River Valley

2.1. Delivering environmental water to the Gwydir River Valley

Flows in the Gwydir River Valley are driven by rainfall in the upper catchment. Almost the entire runoff for the catchment is generated above Pallamallawa, with the western floodplains contributing minimal runoff due to low slopes, absorbent soils and high evaporation rates (Pietsch 2006). Copeton Dam is the major regulated water storage in the Gwydir River Valley. Copeton Dam has a storage capacity of 1 364 GL and regulates about 55 percent of Gwydir system inflows (active storage in Copeton Dam is 1 345 GL (CSIRO 2007). Downstream re-regulating structures at Tareelaroi, Boolooroo and Tyreel divert flows from the Gwydir River into the Mehi River, Carole Creek and Lower Gwydir River/Gingham Watercourse, respectively (Wilson et al. 2009). A number of unregulated tributaries flow into the Gwydir River below the dam; the Horton River is the primary source of unregulated flows.

The principal wetland areas of the Gwydir River Valley targeted by environmental water are the lower Gwydir, Gingham Watercourse and Mallowa Wetlands (NSW Department of Environment, Climate Change and Water [NSW DECCW] 2011). The Gwydir Wetlands is a key asset in the Gwydir River Valley which forms an inland terminal wetland in the downstream reaches of the Gwydir River and Gingham Watercourse, below Moree. Four sites in the lower Gwydir and Gingham are internationally recognised under the Ramsar Convention and other international agreements for migratory species for their special habitat value for waterbirds. These are ‘Windella’, ‘Crinolyn’ and ‘Goddard’s Lease’ on the Gingham Watercourse and ‘Old Dromana’ on the Lower Gwydir Watercourse (NSW Office of Environment and Heritage [NSW OEH] 2012). When flooded, the wetland sustains up to hundreds of thousands of breeding colonial waterbirds. The primary ecological features of the wetlands are large expanses of vegetation, including large areas of coolibah woodland, water couch and the largest stand of marsh club-rush in New South Wales (NSW) (NSW DECCW 2011; Bowen and Simpson 2010).

The Mallowa Creek breaks off the Mehi River approximately 50 km downstream of Moree. Prior to the construction of the Mallowa Regulator in 1983, many fresh flows would have passed through Mallowa Creek and sections of the floodplain. These fresh flows are now diverted down the Mehi River. While not as extensive as the Gwydir Wetlands the Mallowa Wetlands supports a diverse wetland and floodplain vegetation assemblage that is representative of native vegetation of the Gwydir River Valley. Importantly, it also has less of a Lippia presence. The native vegetation of the Mallowa Creek provides valuable habitat for waterbirds, woodland birds and other fauna (Torrible et al. 2009).

The Gwydir and Mallowa Wetlands play a substantial part in the biological and ecological functioning of the Murray-Darling Basin, as the major wetlands in the Basin are not inundated simultaneously and therefore habitat availability varies across the Basin spatially and temporally. Since flooding in the Gwydir Wetlands are not always synchronous with flooding of other Murray-Darling Basin wetlands, such as the Macquarie Marshes or Narran Lake, the Gwydir Wetlands play an important role on a regional scale.

The Mehi River and Carole Creek are major distributaries of the Gwydir River. Moomin Creek branches off the Mehi River downstream of Moree and rejoins the River just before its confluence with the Barwon River at Collarenebri. Carole Creek connects to the Barwon River through the Gil Gil Creek in the Border Rivers catchment. The Mehi River and Carole-Gil Gil Creek transport about 6 per cent of the average flow at Pallamallawa to the Barwon River (Pietsch 2006).

The Sustainable Rivers Audit found that the lowland zone of the Gwydir Valley was rated as poor for both fish and macroinvertebrates (Davies et al. 2012). Native fish populations in

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the Gwydir and across the Murray-Darling Basin have been impacted by changes in the natural flow regime, reduction in habitat quality and availability, and barriers to migration (Copeland et al. 2003). Changes in the frequency, size, duration and timing of flow events have negatively impacted on the availability of food, habitat and breeding opportunities for native fish (Rolls et al. 2013, Baumgartner et al. 2013). The majority of native fish species in the lower Gwydir spawn during the spring and summer season with rises in water temperature and/or water levels. Up to 20 native fish species occur in the Gwydir catchment with most species still occurring in the middle Gwydir catchment (Wilson et al. 2009; NSW DECCW 2008).

Figure 1: The Gwydir River Valley.

2.2. Operational and management considerations for 2014–15 in the Gwydir River Valley

The delivery of environmental water in the Gwydir River Valley is complex as flow capacities are greatly reduced in the downstream direction, with the Gwydir River having the greatest contraction in capacity. A small increase in flows at Pallamallawa can cause over bank flow downstream. The delivery of environmental water in the Gwydir catchment is also constrained by a number of other factors, including the release capacities from storages, channel capacities, proximity of cropping to watercourses, control structures and various operating practices.

Watering options have been developed in consideration of the release capacities outlined in the Water Sharing Plan for the Gwydir Regulated River Water Source. The Murray-Darling Basin Authority has recently published Preliminary Overview of Constraints to Environmental Water Delivery in the Murray–Darling Basin (Murray-Darling Basin Authority [MDBA] 2013b)and Constraints Management Strategy 2013 to 2024 (MDBA 2013a) which also provide further information about constraints to environmental water delivery in the Gwydir Catchment.

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http://www.mdba.gov.au/what-we-do/water-planning/managing-constraints

http://www.mdba.gov.au/media-pubs/publications/constraints-overview


The distribution of regulated flow in the low lying wetlands depends on the amount of extraction between the control structures and the wetlands. Where possible, environmental deliveries will be planned to mimic patterns of natural inundation and ensure core wetland areas receive water during the warmer summer months for a sufficient period of time. However, spring and early summer deliveries of environmental water to the wetlands are constrained by risks to crops within wetland areas during the harvest period.

During periods of peak demand channel capacity is a significant constraint in meeting both consumptive and environmental demand. Where channel capacity is likely to be exceeded river operators may rationalise available capacity between water users. This can be compounded by cropping and harvest cycles pushing environmental water deliveries later in the season reducing the available time window for delivery to core wetland areas. Under these circumstances the ecological objectives of environmental water may be at risk due to compromised delivery of environmental water.

In-stream watering actions, particularly in the Mehi River and Carole Creek, may be timed to occur prior to the main period for the delivery of irrigation water. Delivery of irrigation water following an in stream action may contribute to environmental outcomes. While environmental objectives for such actions target the length of the system the environmental water delivery must be accounted for at a single point in the system. Extractions downstream of the accounting point may reduce the environmental outcomes in the lower reaches of the system. In-stream deliveries to the Mehi River have the potential to contribute to environmental outcomes in the Barwon-Darling system, downstream of Collarenebri.

Operational considerations such as delivery methods, opportunities, constraints and risks will differ depending on the inflow scenario and are summarised in Table 2. These considerations will be assessed throughout the year as decisions to make water available for use are made and implemented. This includes refining the ecological objectives, assessing operational feasibility and potential risks and the ongoing monitoring of the seasonal outlook and river conditions.

Environmental water may be made available for some watering options from the NSW Office of Environment and Heritage (NSW OEH) either as adaptive environmental water or discretionary planned environmental water to deliver common and complementary environmental outcomes.

Table 2: Operational considerations for the Gwydir River Valley in 2014–15.

Inflow scenario Very low

Low Moderate

High Very high

Opportunities Manage the recession of naturally occurring high flows to provide for a more natural flow pattern.Use environmental water in conjunction with, or to maximise the environmental benefit of, naturally occurring river flows. Augment a peak flow and/or managed recession.

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Inflow scenario Very low

Low Moderate

High Very high

Use environmental water to support bird reproduction events and aquatic species propagation/reproduction requirementsAugment regulated flows to improve environmental outcomes.End of system flows contribute to additional environmental outcomes in the Barwon-Darling system. Constraints 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.Cropping and harvest practices may reduce available time window for delivery of environmental water limiting inundation duration for core wetlands.Consumptive orders may dominate available channel capacity, limiting the opportunity to contribute regulated Commonwealth environmental water. Risks*The provision of Commonwealth environmental water must consider potential inundation impacts to property and infrastructure.*See Section 7 for more information on risk management.

2.3. Valley condition

Between 2002 and 2010 the Gwydir River Valley experienced an extended period of drought, which, coupled with river regulation, had a significant impact on the environmental condition of the valley. Drought breaking inflows were experienced in 2010–11 with very high inflows experienced across the valley in 2011–12. During 2012–14 there was a return to drier than average conditions, particularly throughout summer when rainfall was below average while above average temperatures were experienced.

At the end of the drought in 2010 wetland vegetation was in significant decline. The MDBA’s second Sustainable Rivers Audit report concluded that the aquatic ecosystems of the Gwydir River Valley were in poor overall health (Davies et al. 2012). The native fish community and hydrological condition were rated in poor condition, while the macroinvertebrate community, riverine vegetation and physical form were rated in moderate condition. In the lowland zone, where most assets receiving environmental water are located, fish and macroinvertebates were rated as poor and hydrology as very poor (Davies et al. 2012).

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Following the drought the priority was to restore native vegetation communities to improve and increase habitat for a range of fauna species, such as waterbirds. The goal for the use of Commonwealth environmental water in 2010–13 was to support six to eight months of continuous inundation in low lying wetland areas for at least three consecutive years to restore and maintain wetland vegetation in good condition. This frequency and duration of watering was determined by the known characteristics of the key plant species that occur in the Gwydir wetlands, namely water couch-spike rush and lignum shrubland. This inundation target was considered the minimum threshold for maintaining resilience and ensuring the long-term persistence of these ecosystems (MDBA 2012).

In 2012–13 approximately 42 GL of regulated deliveries of environmental water contributed to maintaining conditions for growth in the eastern sections of the lower Gwydir River and Gingham Watercourse. Regulated deliveries did not reach the western sections of these wetlands due to constrained delivery timeframes as a result of harvest activities and channel capacity constraints. The wetlands dried down during December however they were replenished in late February–March as a result of two unregulated flow events.

Monitoring undertaken by NSW OEH confirmed that in response to three successive years of extended inundation the wetland vegetation extent and condition of communities such as the marsh club-rush sedgeland (listed as critically endangered under the NSW Threatened Species Conservation Act 1995) recovered well. Improved inflows also supported recruitment of native fish and frog species in the Gwydir system. In response to the widespread flooding across the lower Gwydir floodplain in 2011–12, large numbers of colonial nesting waterbirds (predominantly ibis and egrets) bred in the wetlands.

After three years of wetting and good recovery of wetland vegetation the Environmental Contingency Allowance Operational Advisory Committee (ECAOAC) agreed that the strategy for managing the Gwydir Wetlands in 2013–14 was to follow natural cues. The strategy was to supplement an unregulated event if there was sufficient flow. In March 2014 an intense fire burnt through 1 600 hectares of the lower Gwydir wetlands, causing significant damage to the wetland vegetation. Local rainfall and a small unregulated flow days after the fire was beneficial in stimulating the initial recovery of the wetland vegetation. Environmental water could be used in 2014–15 to consolidate the recovery of wetland vegetation.

The Mallowa Wetlands received water for the first time in 2011–12 from small unregulated flows after a long dry period and the vegetation responded well. This was followed up with environmental watering from Commonwealth and NSW held water in 2012–13. In 2013–14, Commonwealth environmental water was delivered to maintain the current extent of wetland vegetation in a healthy, dynamic and resilient condition providing important refuge habitat for a range of native species and resulted in a frog breeding event. The Mallowa Wetlands was the only large wetland site north of the Macquarie Marshes to be watered during the summer of 2013–14, and provided important drought refuge for a diversity of waterbirds.

2013–14 was also the first year Commonwealth environmental water was used to deliver environmental water in- stream to achieve outcomes for native fish in the Mehi River and Carole Creek which are both known habitat for a range of small and large bodied native fish. This action was developed with, and supported by the ECAOAC and relevant NSW agencies. The objectives were to increase hydrological connectivity, biotic dispersal, primary production and access to in-stream native fish habitat such as benches, bars and snags. Short-term monitoring indicated that the flow was successful in stimulating ecosystem processes of primary production and carbon cycling which support native fish condition. An increase in native fish abundance was observed towards the end of summer across all channels.

Environmental water deliveries in the last four years have supported key species to complete life cycles and contributed to a net improvement in the number and abundance of wetland species, and overall system health. Threatened aquatic species and vegetation

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regeneration 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 availability3.1. Commonwealth environmental water holdings in the Gwydir

River Valley for 2014–15

Commonwealth environmental water holdings available for use in 2014–15 in the Gwydir River Valley are shown in Table 3below.

Table 3: Commonwealth environmental water holdings in the Gwydir Valley as at 31 May 2014.

Entitlement type

Entitlement held (GL)

Long-term average annual yield (GL)

Estimated Carryover from 2013–14 (GL)1

Forecast water availability for 2013–14 (GL)2

Gwydir (high security)

0.4 0.4 0 80–135(maximum 112 available within use limits.) Gwydir (general

security)89.5 32.2 80

Gwydir (supplementary)

19.1 3.6 N/A Up to 19.1

Total 109.0 36.2 80Notes:1. Future decisions about use, transfers and the ability to deliver already approved actions will

affect expected carryover from 2014–15. 2. The forecast for supplementary 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 2013–14. Forecasts are given to the nearest whole gigalitre for regulated entitlements.

The full list of Commonwealth environmental water holdings can be found at www.environment.gov.au/topics/water/commonwealth-environmental-water-office/about-commonwealth-environmental-water/how-much and is updated monthly.

Portfolio management updates for the Commonwealth’s environmental water holdings are available at www.environment.gov.au/topics/water/commonwealth-environmental-water-office/portfolio-management/portfolio-management .

3.2. Other sources of environmental water allocations

Other sources of environmental water that may be used to complement Commonwealth environmental water delivery in the Gwydir River Valley includes water held by NSW OEH. Table 4 below outlines the different environmental water entitlements held by other water holders.

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Table 4: Other potential sources of environmental water in the Gwydir Valley for 2014–15 as at 30 April 2014.

Source Management Authority

Assigned water right (GL)

Environmental Contingency Allowance (ECA)

NSW OEH (with advice from the ECAOAC)

Allocations against 45 GL/year entitlements (15 GL reserved for bird breeding). Maximum balance – 90 GLAccount balance - 89.31 GL

NSW RiverBank Environmental Water Licences

NSW OEH Allocations against 17.092 GL General Security entitlements and 0.441 GL of Supplementary entitlement. Account balance – less than 1 GL

3.3. Natural or unregulated flows and planned environmental water

In addition to water entitlements held by environmental water holders, environmental demands may also be met via natural or unregulated flows and water provided for the environment under rules in state water resource plans (referred to as ‘planned environmental water’).

The Water Sharing Plan for the Gwydir Regulated River Water Source provides for planned environmental water and stock and domestic releases (replenishment flows).

The Gwydir Wetlands often benefit from unregulated tributary flows (downstream of Copeton Dam) protected under the water sharing plan. The water sharing plan protects up to 500 ML/day of inflows from tributaries downstream of Copeton Dam for the Gwydir Wetlands (referred to as 3T Water). In addition 50 per cent of high unregulated flows are protected for the environment with the remaining flow shared across supplementary licences.

Regulated stock and domestic replenishment flows are provided for in the Water Sharing Plan for use in the following systems if required:

up to 6 GL per year to the Gingham Watercourse (no longer required - replaced with a stock and domestic pipeline)

up to 4 GL per water year to the lower Gwydir River

up to 6 GL per water year to Mallowa Creek

up to 4 GL per water year to Thalaba Creek

up to 1GL per water year to Ballinboora Creek.

These regulated and unregulated flows offer opportunities to piggy back Commonwealth environmental water and increase the potential for environmental objectives to be achieved.

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4. Planning for water use in the Gwydir River Valley in 2014–15

4.1. Planning for a range of inflows in 2014–15

In addition to influencing opportunities, constraints and risks in relation to environmental watering (see Table 2), inflows are a primary driver of resource availability. Resource availability reflects a combination of the allocations available to the Commonwealth Environmental Water Holder (Section 3.1) and other environmental water holders (Section 3.2) as well as natural or unregulated flows and planned environmental water (Section 3.3). Carryover from 2013–14 for the Gwydir is likely to be approximately 80 GL (Table 3). Early season allocations (up to 31 July 2014) are forecast to be low.

Consideration of this allocation range relative to the total entitlement volume (Table 3) and the full range of inflows that may be possible suggests that resource availability early in 2014–15 may be moderate. From this starting point, the full range of possible inflows suggests that resource availability over the course of the year could be between very low and very high (Figure 2). The full range of possible inflows increases due to decreasing confidence in anticipating climatic conditions over a longer period of time. As such, the water use options described in Section 5 have been developed for the full range of resource availability. NSW State Water Corporation (NSW SWC) has advised that a Bulk Release delivery strategy will be applied in the Gwydir for 2014–15. While the current resource availability has been assessed as moderate, some options developed for this scenario may not be pursued due to delivery constraints.

Figure 2: How inflows may vary and impact on water resource availability over the course of 2014–15 in the Gwydir River Valley, from a starting point of moderate resource availability.

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4.2. Implementing watering actions throughout the year

Resource availability will change over the course of 2014–15 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 5 to be refined for implementation as required.

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5. Water use options for 2014–155.1. Summary of watering options

Watering options for 2014–15 for the Gwydir River Valley reflect the approach to supply Commonwealth environmental water to contribute to the overall environmental objectives under the Basin Plan’s environmental watering plan. Watering options aim to protect and restore water-dependent ecosystems and their functions and build resilience to risks and threats. The overall aim of Commonwealth environmental watering in the Gwydir River Valley will be to consolidate and protect the ongoing environmental recovery achieved over the last three years in anticipation of a potentially low rainfall and inflow period.

Watering options have been designed to specifically enable the scaling of actions across potential inflow scenarios. This provides flexibility for water use to best complement unregulated inflows and support natural inundation. The provision of Commonwealth environmental water in combination with small to moderate unregulated freshes would promote connectivity between wetlands and support permanent and semi-permanent wetland vegetation recovery and growth, and potentially, recruitment opportunities for a range of waterbird and native aquatic species (e.g. fish, frogs, turtles, invertebrates), which are sensitive to environmental triggers such as rising or falling water levels in particular seasons.

Where required, regulated environmental water deliveries will typically seek to enhance low to moderate flows and support the hydrological requirements of key wetland plant species in the low lying areas of the wetlands, namely water couch and marsh club-rush. Wetland vegetation provides critical breeding habitat for waterbirds and other fauna. Consideration will be given to providing flows to the lower Gwydir area burned in the March 2014 fire to support its ongoing recovery. River flows will also seek to provide for in-stream refuge sites during periods of extended low or no flow. Consideration may also be given to augmenting modified river management practices that may be implemented by river operators in response to low inflows, such as block releases of consumptive water orders. Where possible, Commonwealth environmental water will be delivered to benefit multiple sites to maximise the outcomes.

Watering options have not been developed for very high resource availability in recognition that at these times, large areas of the Gwydir would likely experience large unregulated inflow events. During large floods, unregulated flows pass overbank and river operators have little or no influence on how water is distributed on the floodplain and into wetlands. Such flooding would achieve most environmental outcomes and provision of additional environmental water would likely cause adverse third party impacts. However, for smaller events under high resource availability, Commonwealth environmental water may be delivered as floodwaters recede to extend the overall period of inundation of core wetland areas and increase the chance of long term ecological outcomes such as successful waterbird reproduction.

Feedback has been sought during the development of water use options for 2014–15 using existing state frameworks, for example, Environmental Water Advisory Groups and State Water Customer Service Committees. This feedback has been incorporated into the water use options where appropriate, particularly in relation to implementation risks and opportunities to improve outcomes through environmental water delivery.

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 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

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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: [email protected].

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mailto:[email protected]

Table 5: Potential watering options for 2014–15 for the Gwydir River Valley.

Applicable level(s) of resource availability(see Section 4)

Very Low Low Moderate High

Option 1 – Gwydir WetlandsProvide base flows to

protect vegetation and maintain drought refuge habitat for waterbirds.

Contribute to base flows and freshes to provide connectivity between wetlands, maintain vegetation extent and condition, and support opportunities for reproduction for a range of waterbird and other native aquatic species.

Option 2 – Mallowa Wetlands Contribute to base flows and freshes to provide connectivity between wetlands, maintain vegetation extent and condition, and support opportunities for reproduction for a range of waterbird and other native aquatic species.

Option 3 – Effluent streams of the Gwydir system (e.g. Lower Gwydir River, Mehi River and Carole Creek)

Contribute to base flows to refresh drought refuges and reduce the risk of degrading water quality.

Contribute to natural and/or regulated flows to support hydrological connectivity increasing fish

habitat availability, supporting ecosystem processes, improving native fish condition and supporting

opportunities for breeding.

Option 4 – In-stream low flow base flow (downstream of Copeton Dam to lower Mehi River)

Contribute to base flows to refresh drought refuges and reduce the risk of degrading water quality.

Options unlikely to be pursued under this resource availability.

Option 5 – Wetland small-bodied native fish contingency

Contribute to wetland refugial habitat for small-

bodied native fish.

Contribute to natural and/or regulated flows to support hydrological connectivity increasing fish habitat

availability and supporting fish condition, breeding and dispersal.

Options unlikely to be pursued under this

resource availability.

Option 6 – Waterbird reproduction and fledging contingency

Options unlikely to be pursued under this resource availability.

If required, augment natural flows to support key species to complete life cycles in low lying wetlands for example water bird reproduction and fledging.

Note: Under certain resource availabilities, options may not be pursued for a variety of reasons including that environmental demand may be met by unregulated flows, and that constraints and/or risks may limit the ability to deliver environmental water.

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5.2. Assessment of environmental watering options

Option 1 – Gwydir Wetlands

Catchment: Gwydir

Complex: Gwydir Wetlands

Site: Lower Gwydir and GinghamApplicable level(s) of resource availability: Very Low to High Relevant flow component:

Base flows Fresh flows Bank-full flows Over-bank flows

Expected inundation extent: Floodplain inundation Wetland inundation

Background: From 2010–11 to 2012–13 a series of unregulated flows, in combination with

Commonwealth and NSW environmental water, inundated large areas of the Gwydir Wetlands supporting the recovery of wetland vegetation communities following a long period of dry conditions and vegetation decline. This period also supported a major bird breeding event in the northern basin (summer 2011–12).

No significant rainfall occurred in 2013–14 and the Gwydir Wetlands were allowed to enter a drying phase. While periods of drying are consistent with a natural hydrological regime, the 2013–14 season was drier than anticipated. Evidence of this was seen where an intense fire occurred in part of the lower Gwydir wetlands in March 2014. As such, a demand for critical wetland needs has developed, putting at risk the recovery achieved in 2010–13.

For 2013–14 the ECAOAC agreed that the watering strategy for the Gwydir Wetlands was to follow natural cues. This was consistent with the agreed strategy of three years of wetland watering to support recovery and increased resilience of wetland vegetation.

Summary of watering option: The purpose of the option is to provide flows into the low lying wetland areas along the

Gingham watercourse and lower Gwydir to maintain the benefits of inundation that occurred during 2010–13 including vegetation condition and extent. Contributing to maintaining habitat quality and ecosystem diversity will support the survival of flora and fauna, and ongoing resilience of the Gwydir Wetlands.

Under very low resource availability, the purpose of this option is to provide base flows to protect core wetland areas from excessive drying. If dry conditions continue in 2014–15, it will be critical to maintain drought refuges within the Gwydir for waterbirds and other fauna. Maintaining refugial habitat will be important not only within the Gwydir River Valley but also at the scale of the northern Murray-Darling Basin.

The preference is for the provision of Commonwealth environmental water in combination with unregulated flows. Commonwealth supplementary water (if access is triggered) could be used to protect a proportion of naturally occurring small to moderate fresh flows. Deliveries from the dam will typically seek to enhance low to medium in-channel river flows and inundation of low lying wetland areas.

Timing All year (most likely spring to autumn)

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Volume of Commonwealth environmental water

Up to 50 GL (including up to 10.1 GL of supplementary water, if access triggered).Total volumes including NSW held and planned environmental water are to be confirmed.

Action undertaken in this catchment previously:

Yes No

Similar action has been undertaken elsewhere in the Murray Darling Basin:

Yes No

Operational considerations and feasibility: This option will be coordinated with NSW OEH to ensure complementary delivery. NSW

OEH manage held and planned environmental water for NSW (the Environmental Contingency Allowance).

Where possible this option will be avoided during winter cropping periods to minimise third party impacts (e.g. planting and harvest).

In delivering environmental flows to the Gwydir Wetlands, early season ‘pre-wetting’ watering may maximise benefits and mitigate against channel capacity constraints later in the season. Pre-wetting would be restricted to in-channel flows to minimise third party impacts and timed to maximise the growth of native wetland vegetation. Pre-wetting will only be considered where there are complementary control measures to minimise the risk of spreading weeds, such as Lippia (Phyla canescens).

Target events will be selected taking into account factors including likely alteration of the natural hydrograph, period since last similar event, seasonality, species likely to benefit, potential risks (including undesirable inundation of winter crops), secondary benefits and volume of water required.

This option may not be required if other flows (e.g. high unregulated flows) occur that are sufficient to contribute to vegetation recruitment and extent, and survival and growth of native species.

Stakeholder feedback: NSW OEH has advised that Lippia will respond more quickly than native species with

late autumn/winter flows and therefore have a growing advantage over natives. For this reason, should a pre-watering strategy be employed, in-channel flow commencing in spring is the preferred option.

The ECAOAC supports environmental watering in the Gwydir Wetlands in 2014–15 in consideration of the dry conditions experienced in 2013–14 and to support the post-fire recovery of the marsh club-rush sedgeland on ‘Old Dromana’. Consistent with previous years of environmental watering, delivery of environmental water will remain in-channel until harvest is complete.

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Option 2 – Mallowa Wetlands

Catchment: Gwydir

Complex: Other Gwydir Catchment Sites

Site: Mallowa WetlandsApplicable level(s) of resource availability: Very Low to High Relevant flow component:

Base flows Fresh Bank-full flows Over-bank flows


Background: Following an extensive dry period, the Mallowa Wetlands received environmental water

in 2012–13 and 2013–14. The vegetation has shown good signs of recovery and its habitat value has been demonstrated by a high number of waterbird species visiting over this period. The Mallowa Wetlands was the only site north of the Macquarie Marshes to receive water in spring–summer 2013–14, providing critical drought refuge in the northern Basin

The Mallowa Wetlands received small unregulated flows in 2011–12, and delivery of environmental flows further increased inundation extent in 2012–14. With the dry conditions in 2013–14 a further year of wetting would be beneficial to build on the outcomes achieved to date by supporting the recovery of the wetlands and building the resilience of the system.

Summary of watering option: Inundation in 2014–15 would support hydrological connectivity between wetlands,

further recovery of vegetation extent and condition, as well as provide habitat for a range of waterbirds and native aquatic species (e.g. fish, frogs, turtles, invertebrates). Contributing to improved habitat quality and increased within-ecosystem diversity would support survival and successful reproduction of native birds, fish and other fauna.

Under very low resource availability, the purpose of this option is to provide base flows to protect core wetland areas from excessive drying. If dry conditions continue in 2014–15, it will be critical to maintain drought refuges within the Gwydir for waterbirds and other fauna. Maintaining refugial habitat will be important not only within the Gwydir River Valley but also at the scale of the northern Murray-Darling Basin.

The preference is for the provision of Commonwealth environmental water in combination with unregulated flows. Commonwealth supplementary water (if access is triggered) could be used to protect a proportion of naturally occurring small to moderate fresh flow. Deliveries from the dam will typically seek to enhance low to medium in-channel river flows and inundation of low lying wetland areas.

Timing All year (most likely spring to autumn)


Up to 20 GL Total volumes including NSW held and planned environmental water are to be confirmed.


Yes No


Yes No

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Where possible this option will be avoided during winter cropping periods to minimise inconvenience to landholders.

Delivery is constrained to channel capacity at Mallowa Creek offtake. Commonwealth environmental water will be accounted for at Mallowa Creek offtake. If a pre-wetting strategy were to be employed prior to the harvest of winter crops Commonwealth environmental water will be delivered at a lower flow rate to avoid breakouts from the main channel.

This option may not be required if other flows (e.g. stock and domestic replenishment flows) are adequate to support vegetation recruitment and extent, and survival and growth of native species.

Stakeholder feedback: NSW OEH has advised that after several consecutive years of watering the response of

the wetland vegetation in the Mallowa has been very positive, attracting a variety of waterbird species. However, considering its highly degraded condition prior to 2011, the recovery of the Mallowa could benefit from further watering in 2014–15.

The ECAOAC supports the existing strategy of 3 years of watering in the Mallowa Wetlands. Ongoing communication with landholders on the timing and duration is critical. Consistent with previous years of environmental watering, delivery of environmental water will remain in-channel until harvest is complete.

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Option 3 – Effluent streams of the Gwydir system

Catchment: Gwydir

Complex: Gwydir Catchment River Flows

Site: In-stream e.g. lower Gwydir River, Mehi River, Moomin Creek and Carole Creek.Applicable level(s) of resource availability: Very Low to HighRelevant flow component:

Base flows Fresh flow Bank-full flows Over-bank flows


Background: The Gwydir River Valley is known habitat for a range of native fishes including large-

bodied species such as Murray cod, golden perch and freshwater catfish. A number of small-bodied species also occur in the Gwydir such as Murray Darling rainbowfish, spangled perch and bony bream. The second Sustainable Rivers Audit rated the condition of fish communities in the Gwydir River Valley as poor. The health of higher trophic levels such as fish community composition and abundance is a good indicator of overall ecosystem health.

Summary of watering option: The purpose of the option is to enhance in-stream flows by contributing to regulated

and unregulated flows along the effluent streams of the Gwydir system to the end of the system. This will support in-stream ecological function and nutrient cycling, contributing to the health of in-stream habitat and maintaining water quality. Connecting and extending the wetted period of benches and anabranches with the main channel will contribute to nutrient cycling, driving food production for native fish species and other aquatic fauna such as shrimp.

The provision of Commonwealth environmental water in combination with regulated (including irrigation deliveries) or unregulated flows will support native fish condition and reproduction by providing improved opportunities for fish to access habitat to feed, find shelter and reproduce. The option aims to stimulate fundamental in-stream ecological processes to provide improved conditions for spawning. Increasing the opportunities for recruitment of small bodied species is likely to benefit large bodied species such as Murray cod and golden perch. Recruitment of golden perch is known to happen in the lowland areas of the catchment.

Under very low to low resource availability, the purpose of this option is to provide base flows to protect refugial in-stream habitat such as pools, and mitigate against declining water quality.

Under moderate to high resource availability the purpose of this action is to augment regulated and unregulated flows at key times known to be important for native fish outcomes, to extend the duration of flow events, mitigate against sudden drops in flow, and provide a tapered flow recession. Commonwealth supplementary water (if access is triggered) could be used to protect a proportion of unregulated fresh flows.

Timing All year, most likely spring to summer


Up to 20 GL (including up to 9 GL of supplementary water, if access triggered)

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Yes No


Yes NoOperational considerations and feasibility: This option will be coordinated with NSW OEH to ensure complementary delivery. NSW


Water may not be delivered to all three streams. Outcomes may also be achieved in delivering water for other actions (e.g. in the Gwydir River in delivering water to the Lower Gwydir and Gingham Watercourse). Delivery of water will be prioritised based on the water available, presence and condition of suitable in-stream habitat and predicted stream flow during the event (regulated and unregulated water sources).

The ecological requirements of native fish species vary in terms of spawning time, water temperature, in-stream habitat requirements and preferred flow regime. Native fish species in the Gwydir typically reproduce during spring and summer associated with an increase in flow and water 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 spawning ‘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 Murray-Darling Basin valleys. Deliveries during spring to summer may contribute to larval dispersal, larval/juvenile fish growth and survival.

Target events will be selected taking into account factors including likely alteration of the natural hydrograph, period since last similar event, seasonality, species likely to benefit, potential risks (including cold water pollution from dam releases), secondary benefits (including where water provided in the Mehi River could contribute to flow requirements in downstream systems) and volume of water required.

Should no suitable supplementary or unregulated event occur, held environmental water may be used to deliver the full flow event.

Should special delivery arrangements be introduced in response to very dry conditions, such as the block release of irrigation orders, environmental water may be used to augment these releases to provide hydrological connectivity to the end of the system.

Consideration will also be given to coordinating delivery such that return flows are used to contribute to downstream outcomes, namely longitudinal connectivity (especially under very low to low resource availability scenarios where end of catchment discharge would otherwise be negligible).

Stakeholder feedback: The ECAOAC supports the use of environmental water to improve outcomes for native

fish in the Gwydir. Gwydir Valley Irrigators Association provided the Office with a number of

recommendations in response to the 2013–14 in-stream watering action relating to decision making processes and exploring opportunities for joint delivery options with irrigation communities to achieve outcomes as efficiently as possible.

The Office welcomes advice on opportunities, where practical, to integrate irrigation delivery and environmental water to achieve environmental outcomes while not compromising irrigation delivery.

The Office works closely with delivery partners in the design and implementation of watering actions in the Gwydir, including NSW OEH, NSW Office of Water, NSW Fisheries and NSW SWC.

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Option 4 – In-stream low flow base flow

Catchment: Gwydir

Complex: Gwydir Catchment River Flows

Site: downstream of Copeton Dam to lower Mehi RiverApplicable level(s) of resource availability: Very Low to Low Relevant flow component:



Background: 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, water quality safe, and provide drought refuge for a range of aquatic species. Maintaining drought refuge habitat is a key factor for influencing the survival of aquatic species during dry years.

Summary of watering option: The purpose of the option is to provide hydrological connectivity to in-stream habitat, to

ensure the persistence of pools as refuge, and to reduce the risk of degrading water quality conditions (particularly low dissolved oxygen levels).

The proposed option would occur after a protracted period of low flow to maintain essential refuge habitat for aquatic species and fundamental ecosystem functions.

To achieve this outcome, Commonwealth environmental water will contribute to flows as required. Commonwealth environmental water will be delivered as in-channel flows from regulated entitlements and managed within the normal water delivery arrangements.

Timing All year (subject to low flow triggers)


Up to 15 GL


Yes No


Yes No

Operational considerations and feasibility: This delivery option would be delivered by supplementing other water sources (such as

irrigation deliveries) to provide longitudinal connectivity and extend the duration of access to a range of habitats.

Should special delivery arrangements be introduced in response to very dry conditions, such as the block release of irrigation orders, environmental water may be used to augment these releases to provide hydrological connectivity to the end of the system.

This option will be coordinated with NSW OEH to ensure complementary delivery. NSW OEH manage held and planned environmental water for NSW (the Environmental Contingency Allowance).

Stakeholder feedback: The ECAOAC supports the use of environmental water to protect refuge sites from

drying down completely, which is a risk during river operations under block releases.

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Catchment: Gwydir


Site: semi-permanent waterholes e.g. lower Gwydir and GinghamApplicable level(s) of resource availability: Low to HighRelevant flow component:



Background: The life history stages of some small bodied fish species involve dispersal onto the

floodplain during large flooding events to reproduce. There are a number of waterholes in the lower Gwydir and Gingham that fill during large flooding events and become important habitat for a number of small bodied fishes (e.g. olive perchlet). As the floodwaters recede, fish may become stranded in these waterholes until the next flood event.

In 2013–14 the olive perchlet (Ambassis agasisizii) (endangered population Fisheries Management Act 1994 (NSW)) was observed for the first time in the Gwydir catchment in the Boyanga Waterhole and Gingham Waterhole, on the Gingham watercourse.

Many native fish species that used to be widespread in the Murray-Darling Basin now have patchy distributions. Protecting known populations, where possible, in between wet years is important to enhance these species’ capacity to recolonise suitable habitat during higher flow periods.

Summary of watering option: The purpose of this option is to provide water to semi-permanent waterholes such as in

the lower Gingham and Gwydir to protect refugial habitat for small-bodied native fish. While these waterholes are semi-permanent and are prone to natural drying, it may be

feasible to provide additional water to maintain water levels and mitigate degrading water quality, sustaining refugial habitat for native fish until a flood event reconnects the waterholes with the channel.

Timing All year, most likely spring to summerVolume of Commonwealth environmental water

Up to 10 GL


Yes No


Yes NoOperational considerations and feasibility: The feasibility of this action will be determined by the ecological requirements of the

native fish species detected in any waterholes, and the practicality of delivering water to sites. The decision to undertake this option will also depend on the seasonal outlook, time since last flood and likelihood of persistence of any stranded populations.

Information, recommendations and cooperation between delivery partners such as NSW OEH, NSW DPI Fisheries, NSW SWC and NSW Office of Water is important.

This option could be incorporated with other delivery options.Stakeholder feedback: No specific feedback received.

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Option 6 – Waterbird reproduction and fledging contingencyCatchment: Gwydir


Site: Gwydir Wetlands, Mallowa WetlandsApplicable level(s) of resource availability: Moderate to HighRelevant flow component:

Base flows Fresh flows Bank-full flows Over-bank flows


Background: The wetlands in the Lower Gwydir system are recognised as being of international

importance under the Ramsar Convention and other migratory bird agreements. It is an important breeding area for waterbirds as well as resting and staging points for migratory bird species. When flooded, the wetland sustains up to hundreds of thousands of breeding colonial water birds, which feed in the wider wetland area.

Species that breed in the Gwydir Wetlands include: little egret, intermediate egret, great egret, nankeen night heron, straw-necked ibis, Australian white ibis, glossy ibis and magpie geese.

Summary of watering option: The purpose of the option is to support waterbird reproduction events. If a waterbird

reproduction event commences but system inflows are not sufficient to sustain water levels in the area, additional environmental water may be required to support fledging of chicks. In these circumstances, additional environmental water may be provided to reduce the risk that adult birds would abandon nests and the waterbird reproduction event would be unsuccessful.

Timing Spring/Summer/Autumn


Up to 10 GL


Yes No


Yes No


OEH manage held and planned environmental water for NSW (including the Environmental Contingency Allowance).

Colonial waterbird reproduction sites along the Gingham watercourse are most likely to require support by deliveries. The precise location of the potential watering event will become apparent should reproduction commence. The volume and delivery pattern will be highly dependent on the location of the waterbird reproduction event, the degree to which it requires support and whether support from environmental water deliveries is feasible.

This option may not be required if other flows (e.g. natural flood flows) are sufficient to support the waterbird reproduction to completion. This option could be incorporated with other delivery options.

Stakeholder feedback: The ECAOAC and other delivery partners agree that it would be highly undesirable for a

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breeding event to be triggered and to fail. General consensus from relevant stakeholders is to provide support as needed to ensure breeding events are successful.

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5.3. Options contributing to the Basin Annual Environmental Watering Priorities

Each year the Murray-Darling Basin Authority develops Basin annual environmental watering priorities (‘Priorities’). All environmental watering in the Murray-Darling Basin, including the use of both held and planned environmental water, is to be undertaken having regard to the Priorities.

The Priorities are not an exhaustive list of all important assets and functions throughout the Basin and hence do not exclude other watering actions undertaken by environmental water holders and managers.

The 2014–15 Basin annual environmental watering priorities were published on 30 June 2014 and are available here: www.mdba.gov.au/what-we-do/environmental-water/environmental-watering-priorities/priorities-14-15. Table 6 identifies the relevant Priorities for the Gwydir River Valley and the watering options that could contribute to achieving the identified outcomes.

Table 6: 2014–15 Basin annual environmental watering priorities for the Gwydir River Valley

2014–15 Basin annual environmental watering priorities relevant to the Gwydir River Valley

Watering options that may contribute to the achievement of priority outcomes

Theme: Connect rivers and floodplains

Gwydir wetlands: Improve the condition and maintain the extent of wetland vegetation communities in the Gwydir Wetlands (including Ramsar sites) by restoring hydrological connectivity and a flow regime that meets ecological requirements.



Theme: Enhance and protect refuge habitat

Native fish in the northern Basin: Improve survival of native fish populations by enhancing and protecting dry period refuge habitat in the northern Basin


Option 3 – Effluent streams of the Gwydir system

Option 4 – In-stream low flow base flow


Waterbird Refuge: Maintain waterbird habitat, including refuge sites, and food sources, to support waterbird populations across the Murray-Darling Basin. Support waterbird breeding, where feasible



Option 6 – Waterbird reproduction and fledging contingency

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http://www.mdba.gov.au/what-we-do/environmental-water/environmental-watering-priorities/priorities-14-15

http://www.mdba.gov.au/what-we-do/environmental-water/environmental-watering-priorities/priorities-14-15

6. Accounting for the use of Commonwealth environmental water

6.1. Water use accounting

Across NSW, Commonwealth environmental water is generally transferred to NSW OEH’s environmental accounts. NSW OEH is then responsible for making arrangements to deliver the environmental water with river operators such as NSW SWC. In some instances, water may be delivered without transferring it to NSW OEH environmental accounts.

River flows will be accounted for at storages or at downstream flow gauges and will be reported to the Office by NSW OEH. Where applicable, water delivered to individual wetland sites will be accounted at flow gauges or metered pumps at those sites.

6.2. Monitoring

6.2.1. Operational monitoringOperational monitoring is monitoring that 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 Gwydir River Valley, this includes the NSW OEH, NSW SWC, and NSW Office of Water.

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.

6.2.2. Long term intervention monitoringThe Long Term Intervention Monitoring Project (LTIM Project) is the primary means by which the Office will undertake monitoring and evaluation of the ecological outcomes of Commonwealth environmental watering. The LTIM Project will be implemented at seven Selected Areas over a five year period from 2014–15 to 2018–19 to deliver five high level outcomes (in order of priority):

1. evaluate the contribution of Commonwealth environmental watering to the objectives of the MDBA’s Environmental Watering Plan

2. evaluate the ecological outcomes of Commonwealth environmental watering at each of the seven Selected Areas

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3. infer ecological outcomes of Commonwealth environmental watering in areas of the Murray-Darling Basin that are not monitored

4. support the adaptive management of Commonwealth environmental water

5. monitor the ecological response to Commonwealth environmental watering at each of the seven Selected Areas.

This approach has a sound scientific basis that allows the Office to understand environmental outcomes in catchments where around 90 per cent of Commonwealth environmental water is held. A Monitoring and Evaluation Adviser will undertake evaluation at the Basin scale.

The seven Selected Areas where monitoring will occur are:

1. Junction of the Warrego and Darling rivers

2. Gwydir River system

3. Lachlan River system

4. Murrumbidgee River system

5. Edward-Wakool River system

6. Goulburn River

7. Lower Murray River.

These areas were chosen to be representative of Commonwealth environmental watering across the Murray-Darling Basin.

A Monitoring and Evaluation Plan that captures the long-term arrangements between scientific organisations and delivery partners has been developed for the Gwydir River system Selected Area.

Results from the LTIM Project will be published on the Office’s website and the data will be publicly available.

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7. Next steps – from planning to water delivery

Local knowledge and experience is critical to effectively manage and deliver Commonwealth environmental water. Stakeholders have an important role and provide critical information that informs each stage of the process for managing Commonwealth environmental water (see Figure 3).

The planning phase is the first stage in the cycle of environmental water management. The planning process occurs on an annual basis between January and the end of June, and each planning document represents the culmination of months of work and consultation. Throughout the planning process the Office consults closely with state environmental water managers, river operators and local environmental water advisory groups. The information gathered as part of the planning process feeds into the development of the options for the following water year.

Towards the beginning of the new water year the focus shifts from planning to implementation. Greater consideration is given to current and forecast catchment conditions and water availability to determine which of the options identified during the planning process can feasibly be implemented. Local on-ground knowledge is important for detailing a specific watering action including the flow magnitude, timing, triggers for commencement, rates of rise and fall and the area to be inundated. Once an action has been scoped in more detail an assessment against the following criteria is undertaken:

ecological value of the river, floodplain or wetland

expected outcomes from watering

potential risks of watering

long-term sustainability and management of the site

cost effectiveness and feasibility of watering.

Site managers and local community groups provide important information to inform these assessments. In particular, information related to potential risks provides critical input to the detailed risk assessment that is undertaken before a decision is made on a watering action. For further information see the Framework for Determining Commonwealth environmental water use (available at: www.environment.gov.au/resource/framework-determining-commonwealth-environmental-water-use.

Following the scoping and assessment of potential watering actions, the Commonwealth Environmental Water Holder is required to make a decision on whether or not to commit the water and funds required to support the watering action. In doing so the Commonwealth Environmental Water Holder also has regard to the Basin Annual Priorities as required by the Basin Plan.

When a decision is made by the Commonwealth Environmental Water Holder to proceed with a watering action arrangements for implementation are made with delivery partners. This includes river operators, who manage the delivery of the water and operational monitoring. Local community involvement is crucial at this stage of implementation and during water delivery as conditions can change rapidly and may result in the need to adjust, suspend or even cancel the watering action.

Upon completion of the watering action, a review process, which generally takes place from March through to October, informs future watering actions and long-term

34

management. This review is informed by the weekly operational monitoring, results of ecological monitoring, and feedback provided by site managers and the local community.

Stakeholder input to CEWO required

Completion of all watering actions within a catchment –Watering Action Review

Ecological monitoring:• Short term ecological monitoring by other agencies• Long Term Intervention Monitoring

REVIEW

Mar

-O

ct 20

15

Detailed planning and scoping of feasible watering actions

Preparation of paperwork for decision includes assessment against criteria

Decision by CEWH

Implementation of watering action

Ongoing weekly operational monitoring

Watering action finished – acquittal report

Detailed risk assessment

IMPLEMENTATION

Change, suspend or cancel watering actions to reflect changing conditions

Jun 2

014-

Jun

2015

Approval of Water Use Options documents by CEWH

Assessment of catchment conditions

Annual planning for Commonwealth environmental water use options

PLANNING

Eliminate unrealistic/ unfeasible options

Jan–

Jun

2014

Figure 3: The annual management process for Commonwealth environmental water.

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8.PartnershipsThe Office has consulted with a range of stakeholders to develop the Commonwealth environmental water use options for the Gwydir River Valley for 2013–14, including our delivery partners as follows:

Murray-Darling Basin Authority

New South Wales Office of Environment and Heritage

New South Wales Office of Water

New South Wales Department of Primary Industries

New South Wales State Water Corporation

North West Local Land Services.

The Office will continue to work with stakeholders and other interested community members in the planning, delivery, management and monitoring of Commonwealth environmental water.

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9. BibliographyBaumgartner, L. J., Conallian, J., Wooden, I., Campbell, B., Gee, R., Robinson, W. A. and Mallen‐Cooper, M. (2013). Using flow guilds of freshwater fish in an adaptive management framework to simplify environmental flow delivery for semi‐arid riverine systems. Fish and Fisheries, Early View (Online Version of Record).

Bowen, S. and Simpson, S. L. (2010). Changes in Extent and Condition of the Vegetation Communities of the Gwydir Wetlands and Floodplain 1996-2008: Final Report to the NSW Wetland Recovery Program. NSW Department of Environment Climate Change and Water, Sydney.

Copeland, C., Neller, S., Schooneveldt-Reid, E., Wales, N. S. and Fisheries, N. (2003). Fish Everywhere: An oral history of fish and their habitats in the Gwydir River. NSW DPI Fisheries.

CSIRO (2007). Water availability in the Gwydir. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. , CSIRO, Australia.

Davies, P., Stewardson, M., Hillman, T., Robert, J. and Thoms, M. (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 2. Murray-Darling Basin Authority, Canberra.

Murray-Darling Basin Authority (2012). Assessment of environmental water requirements for the proposed Basin Plan: Gwydir Wetlands. Murray-Darling Basin Authority, Canberra.

Murray-Darling Basin Authority (2013a). Preliminary Overview of Constraints to Environmental Water Delivery in the Murray–Darling Basin. [online] available: www.mdba.gov.au/media-pubs/publications/constraints-overview, accessed 12 June 2014.

Murray-Darling Basin Authority (2013b). Constraints Management Strategy 2013 to 2024. [online] available: www.mdba.gov.au/what-we-do/water-planning/managing-constraints, accessed 12 June 2014.

NSW Department of Environment, Climate Change and Water (2008). Final report on the Gwydir waterbird and fish habitat study. NSW Wetland Recovery Program. Rivers and Wetlands Unit, NSW Department of Environment and Climate Change, Sydney.

NSW Department of Environment, Climate Change and Water (2011). Gwydir Wetlands Adaptive Environmental Management Plan., NSW Department of Environment Climate Change and Water, Sydney.

NSW Office of Environment and Heritage (2012). Gwydir Wetlands: Gingham and Lower Gwydir (Big Leather) Watercourses Ramsar site. [online] available: www.environment.nsw.gov.au/wetlands/GwydirWetlandsGinghamAndLowerGwydirBigLeatherWatercourses.htm, accessed 12 June 2014.

Pietsch, T. J. (2006). Fluvial geomorphology and late quaternary geochronology of the Gwydir fan-plain. PhD, University of Wollongong.

Rolls, R. J., Growns, I. O., Khan, T. A., Wilson, G. G., Ellison, T. L., Prior, A. and Waring, C. C. (2013). Fish recruitment in rivers with modified discharge depends on the interacting effects of flow and thermal regimes. Freshwater Biology, 58, pp. 1804-1819.

Torrible, L., Sainty, G. and Horcroft, D. (2009). Assessment of the Water Dependent Vegetation and Fauna of the Mallowa Creek, results from a field visit Feb 2009. IRPEC Pty Ltd.

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http://www.mdba.gov.au/what-we-do/water-planning/managing-constraints


Wilson, G. G., Bickel, T. O., Berney, P. J. and Sisson, J. L. (2009). Managing environmental flows in an agricultural landscape: the Lower Gwydir floodplain. Final Report to the Commonwealth Department of Environment, Water, Heritage and the Arts.

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Documents

· Web viewCommonwealth environmental water use options 2014–15: Gwydir River Valley is licensed by the Commonwealth of Australia for use under a Creative Commons By Attribution