Annual Operations Plan Macquarie Valley 2019-20 Acronym Definition

AWD Available Water Determination Contents BLR Basic Landholder Rights BoM Bureau of Meteorology

BWT Bulk Water Transfer Introduction 2 CWAP Critical Water Advisory Panel The Macquarie System 2 CWTAG Critical Water Technical Regulated and unregulated system flow trends 3 Advisory Group Rainfall trends 3 DPI CDI Department of Primary Inflows to Dam 4 Industries - Combined Water users in the valley 4 Drought Indicator

DPIE Department of Planning, Water availability 7 BCD Industry and Environment - storage 8 Biodiversity and Conservation Division Water resource forecast 11 DPI Department of Primary Macquarie catchment - past 24 month rainfall 11 Fisheries Industries - Fisheries Burrendong Dam - past 24 month inflows/statistical inflows 12 DPIE Department of Planning, - past 24 month inflows/statistical inflows 13 Water Industry and Environment - Weather forecast - 3 month BoM forecast 13 Water Burrendong storage forecast 14 FMZ Flood Mitigation Zone

FSL Full Supply Level Annual operations 15 HS High Security Deliverability 17 IRG Incident Response Guide Scenarios 19 ISEPP Infrastructure State Deliverability of ordered water 20 Environmental Planning Policy Critical dates 22 LGA Local Government Areas

ROSCCo River Operations Stakeholder Projects 22 Consultation Committee Operations Management Plan - S&D Stock & Domestic Macquarie Valley Temporary Works 23 vTAG Valley Technical Advisory Group Introduction

This annual operations plan provides an outlook for the coming year in the Macquarie valley. The plan considers the current volume of water in storage and weather forecasts. This plan may be updated as a result of significant changes to the water supply situation.

This year’s plan outlines WaterNSW’s response to the drought in the Macquarie Valley including: • identification of critical dates; • our operational response; and • potential projects to mitigate the impact of the drought on customers and communities within the valley.

The NSW Department of Planning, Industry and Environment’s Extreme Events Policy and Incident Response Guides outline 4 stages of drought. The Macquarie regulated river system is assessed to be in stage 4, which is categorised as ‘critical drought/water shortage’.

The System

In central-western , three major river networks flow north-west to the Barwon River: Castlereagh, Macquarie and Bogan. The of these catchments are an important water source for urban water supply and irrigated agriculture, however groundwater is equally important as a water source in the region.

The catchment covers about 7% of the Basin and provides 8.4% of inflow of surface water for the Basin.

The main tributaries of the Macquarie River below Burrendong Dam are: • Bell River • • • Coolbaggie Creek

BREWARRINA WEIR Macquarie (DARLING NO 15) N BREWARRINA BARWON RIVER NORTH MARSH Key CHANNEL BOURKE Major towns CASTLEREAGH GONGOLGON RIVER Major dams WEIR MONKEY BRIDGE NO.2 system MONKEY BRIDGE River catchment NO.1 WEIR CROOKED CK REGULATOR Macquarie DUCK CK REGULATOR marshes GUNNINGBAR CREEK Regulated weirs ALBERT PRIEST CHANNEL WARREN COOLAH Unregulated weirs BELERINGAR CREEK MUDDAL WEIR

GUNNINGBAR OFFTAKE REG. BELARINGAR TOTTENHAM CREEK WELLINGTON REGULATOR CUDGEGONG WEIR TULLAMORE PEAK HILL WINDAMERE DAM LITTLE RIVER MACQUARIE BELL RIVER RIVER

ORANGE BATHURST

BURRENDONG DAM

2 Regulated and unregulated system flow trends

The catchments are ecologically important as their waters feed the which are Ramsar-listed and nationally important wetlands, and one of the largest freshwater wetlands in the Murray-Darling Basin (MDB).

The Macquarie–Castlereagh catchment is home to about 9% of the population of the MDB, and the large service centres at Dubbo, Nyngan, Narromine and Cobar are regional hubs for health, education and business services. Agriculture in the catchment is diverse ranging from horticulture in the east, dryland grazing and cropping on the slopes, to irrigated cropping and extensive grazing in the west.

The Macquarie and Castlereagh catchments are typical of most MDB catchments, rising in or near the where most of the streamflow originates at high altitude (up to 1,300 metres (m) in the Macquarie catchment) and annual average rainfall is above 600 millimetres (mm). After running through foothills and slopes, the rivers emerge onto expansive plains where rainfall is lower, the climate is warmer, and elevations are less than 300 m.

Groundwater is found in alluvial sediments on the plains in the lower catchment and is generally associated with the ancient channels of the rivers. The highest yielding are located north- west of Narromine. Much of the upper Macquarie catchment and the Bogan catchment is underlain by fractured rock which yields very little groundwater. The Great Artesian Basin underlies the northern part of the Macquarie catchment downstream of Warren.

Rainfall trends

For the period April 2017 to March 2019, lowest-on-record rainfall was observed over southern inland and areas of northwestern New South Wales. Over most of this area, rainfall for the period was less than 50% of the 1961–1990 average. Large areas from central to southwestern Queensland, and northcentral and northwestern New South Wales, into northeastern South , have seen rainfall totals between 40% to 60% of this average, implying that nearly one year’s worth of average rainfall has been missed over this two-year period.

The recent dry periods have been especially severe during the cooler months of April to September, an important time for agriculture and the replenishment of surface and groundwater storages across southern Australia. Averaged over the MDB, the total rainfall over two consecutive April to September periods was the lowest on record, at 217.5 mm. This is around 15% below the previous record, which saw 255.7 mm over the 1940–41 April to September period. It was also the only instance of an April to September rainfall total below 125 mm in two consecutive years.

Rainfall for the combined two-year 2017 and 2018 April to September period was the lowest on record and very much below average (lowest 10% of all such periods) for large parts of southeastern and southwestern Australia. Around 50% of NSW was lowest on record for these two periods combined.

The 2019 winter again saw dry conditions, which means three consecutive winters of below average rainfall.

Over the 24-month period, there has been a large decline in water resources in the northern half of the MDB, including over the Namoi and Upper Macquarie catchments. The Namoi has had the second lowest on record rainfall for equivalent 24-month periods, with rainfall around 62% of the 1961–1990 average. Rainfall in the Upper Macquarie catchment is around 71% of the average.

3 Inflows to Dam

Total inflows to Burrendong Dam since the last general security allocation in August 2017 to the end of July 2019 have been about 90,000 ML. This is about one-third of the previous record low inflow of 269,000 megalitres (ML) for the 24-month period ending in July.

Water users in the valley

Basic Land Holder Rights (BLR)

BLR includes water for stock and domestic extracted from a water source fronting a landholder’s property, or from any underlying the land, and for native title rights. It is estimated that the volume of BLR in the Macquarie is 1,200 megalitres per year (ML/year). The water supply system shall be managed so that it would be capable of maintaining supply to those exercising stock and domestic rights through a repeat of the worst period of low inflows into this water source (based on historical flow information held by the Department of Planning, Industry & Environment – Water, as at 1 July 2004). Sufficient volumes of water must be set aside from assured inflows into this water source and reserves held in Burrendong Dam and Windamere Dam water storages. The Minister for Water may issue an order under section 328 of the Water Management Act 2000 to restrict the exercise of stock and domestic basic rights from this water source to protect the environment, for reasons of public health, or to preserve basic landholder rights.

Domestic and Stock use

The share components of Domestic and Stock access licences authorised to take water from these water sources will total 5,948 ML/year.

Local Water Utilities

The share components of Local Water Utility access licences authorised to take water from these water sources will total 18,805 ML/year, distributed as follows:

Licence Category: Local Water Utility Holder Share Comp Sub-Total 8,700 Dubbo Regional Council - Dubbo 9,000 300 2,000 Mid Western Council 2,600 600 Dubbo Regional Council - Wellington 1,855 1,855 Council 750 750 2,090 Bogan Shire Council 2,750 660 Cobar Shire Council 1,850 1,850 Macquarie & Cudgegong Total: 18,805

4 High Security

The share components of regulated river (High Security) access licences in the Macquarie Regulated River water source totals 17,913 unit shares. Most of the High Security licences are held by the mines, abattoir and the western plain zoo in the valley.

General Security

The share components of regulated river (General Security) licences in the Macquarie Regulated River water source will total 632,428 unit shares. While the General Security irrigators hold 632,428 unit shares, the average allocation over the last 10 years in the valley is 41.7%. The major irrigation industries in the valley are cotton farmers in the Macquarie and Lucerne in Cudgegong.

Of the total licences, 173,531 unit shares are environmental licences held by the Commonwealth and New South Wales.

Supplementary River Access licences

It is estimated that at the time of commencement of this plan, the share components of Supplementary River Access licences authorised to take water from these water sources will total 50,000 unit shares, distributed as follows: • 1290 unit shares in Cudgegong, and • 48708 unit shares in the Macquarie. Six licences totalling 9,718 supplementary unit shares are held by the Commonwealth and New South Wales Governments.

Environmental Water

By limiting long-term extractions to an estimated 391,900 ML/year, this plan ensures that approximately 73% of the long-term average annual flow in this water source (estimated to be 1,448,000 ML/year) will be preserved and will contribute to the maintenance of basic ecosystem health.

Planned environmental water includes: Cudgegong 1. Planned environmental water releases shall be made from Windamere Dam water storage whenever the sum of storage inflows plus tributary inflows downstream of the water storage is capable of producing a flow in the at Rocky Water Hole of at least 150 megalitres per day for two days or more, subject to any start and finish dates. 2. The rate of planned environmental water releases shall be the lesser of: a. storage inflow, b. the rate of release necessary to achieve 1,500 ML/day in the Cudgegong River at Rocky Water Hole. 3. Release of planned environmental water from Windamere Dam shall not be made: a. when the storage level in Windamere Dam water storage is at or below 110,000 megalitres, or b. after the total volume of water released under subclause (2) during any water year has reached 10,000 megalitres. 4. The volume of planned environmental water released from Windamere Dam shall be assessed as: a. the volume of water released in excess of the volume of releases required to meet access licence water orders in the Cudgegong River downstream of Rocky Water Hole, and b. zero, when Windamere Dam is spilling.

5 5. Releases of planned environmental water from Windamere Dam water storage may not be used to supply access licence requirements between Windamere Dam water storage and Burrendong Dam water storage.

6. Once planned environmental water released has entered Burrendong Dam water storage, it shall no longer be designated as environmental water.

Macquarie

1. An environmental water allowance shall be established for environmental purposes downstream of Burrendong Dam and shall be released as specified in the Macquarie Water Sharing Plan (WSP) to improve environmental outcomes in the Macquarie Marshes and Macquarie River between Burrendong Dam and the Macquarie Marshes

2. The volumes credited to and debited from the environmental water allowance are to be calculated according to the following: a. whenever an available water determination is made for regulated river (General Security) access licences, the allowance shall be credited with a volume equal to 160,000 ML multiplied by the number of megalitres per unit share specified in that available water determination b. the volume credited to the allowance shall be distributed between two sub-allowances in the following way: i. sub-allowance one (translucent) is to receive two fifths of the volume, and ii. sub-allowance two (active) is to receive three fifths of the volume,

3. Release of sub-allowance one (translucent) water shall be made from Burrendong Dam according to the following: a. water carried over from the previous water year shall be released before water that has been credited to sub-allowance one (translucent) in the current water year, b. releases shall only be made during the periods 1 June to 30 November (inclusive) and 15 March to 31 May (inclusive) each year,

c. releases shall only be made when: i. the sum of storage inflows plus tributary inflows downstream of Burrendong Dam would be capable of providing a flow of at least 500 ML/day for five days or more in the Macquarie River immediately upstream of Marebone Weir, and ii. the water level in Burrendong Dam water storage is not within the Flood Mitigation Zone (FMZ), or iii. the sum of tributary inflows between Burrendong Dam and upstream Marebone Break is less than or equal to 1000 megalitres per day,

4. The water releases from the FMZ be made to provide beneficial flooding for the regulated Macquarie River, the Macquarie Marshes, Marebone floodplain and effluent creeks. The rate of release shall be the lesser of: a. the storage inflow, or b. the rate of release necessary to achieve up to a maximum flow target of 4,000 ML/day in the Macquarie River immediately upstream of Marebone Weir,

5. Releases of sub-allowance one (translucent) water shall cease when the sum of storage inflows plus tributary inflows reduces to a level which would no longer result in a flow of at least the volume specified by paragraph (c), unless releases of sub-allowance one (translucent) water are being extended by release of sub-allowance two (active).

6 Water availability Available Water Determinations (AWDs) for Macquarie River 1 July 2019

Licence Category AWD Deliverability Domestic and Stock 80% Restricted - please see tables on pages 20-21 Domestic and Stock - domestic 80% Restricted - please see tables on pages 20-21 Domestic and Stock - stock 80% Restricted - please see tables on pages 20-21 Local Water Utility 80% Regulated River (General Security) 0% Restricted - please see tables on pages 20-21 Regulated River (General Security N/A Restricted - please see tables on pages 20-21 carryover allocations Regulated River (High Security) 70% Restricted - please see tables on pages 20-21 Regulated River (High Security) 35% Restricted - please see tables on pages 20-21 Research Regulated River (High Security) 80% Restricted - please see tables on pages 20-21 Town Water Supply Supplementary Water 100% Subject to availability

Current Drought Conditions

The system continues to experience low inflows to both Burrendong and Windamere Dams and downstream tributaries. Over the last 10 years, good inflows occurred in three years: 2010-11, 2011-12 and 2016-17.

Extremely low inflows also occurred in three years: 2013-14, 2014-15, and 2015-16 with the storages during 2016 decreasing to 5%. The last two years 2017-18 and 2018-19 has seen the lowest on record inflows for a 24-month period, with inflows being only 38% of the previous 24-month lowest recorded inflows.

Macquarie Cudgegong Valley Inflows

3,500,000 3,000,000 2,500,000 2,000,000 1,500,000 Inflow (ML) 1,000,000 500,000 0 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 2015-16 2016-17 2017-18 2018-19

Combined Dam inflows Downstream Tributaries

The inflows for the 26-months for Burrendong Dam (August 2017 to September 2019) were around 93,300 ML. This is only 22% of the previous minimum observed inflow of 421,000 ML for a 26-month period ending in September.

7 Burrendong Dam storage As a result of the low inflows over the past two years, the volume of water in Burrendong Dam has slowly declined since being at 127% in October 2016. The graph below shows Burrendong Dam’s behaviour for the 2018-19 water year, compared to the last four water years. From the figure below, it can be seen that the volume of Burrendong Dam was around 87% at the start of the 2017/18 water year, and was drawn down to 36% of total capacity at the end of the water year. During 2018/19 water year, low inflows during the winter led to temporary water restrictions were placed on general security water accounts (irrigation and environmental accounts) to conserve water for critical needs. As the year progressed, inflows remained low. Low rainfall for the third winter in a row in 2019 has resulted in the Burrendong storage commencing the year at 5%. In 2018-19 in Macquarie and in Cudgegong: • about 17,293 ML was supplied to town water • 148,927 ML was provided to general security irrigation • 75,705 ML of licenced environmental water, • planned environmental water of 51,072 ML was provided for environmental customers, and • about 113,000 ML was used to run both regulated Macquarie and Cudgegong rivers with water being lost to groundwater and evaporation.

Burrendong Dam storage

140%

120%

100%

80%

60%

Storage capacity 40%

20%

0% Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun

2014/15 2015/16 2016/17 2017/18 2018/19

Windamere Dam storage

60%

50%

40%

30%

20% Storage capacity

10%

0% Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun

2014/15 2015/16 2016/17 2017/18 2018/19

8 Resource Assessment

The resource assessment is the process of calculating how much water is available based on the rules of the WSP. This is done at the end of the month and when any significant inflow event occurs.

The planning horizon for this resource assessment is 11 to 24-months depending on the month of assessment. Taken into consideration is the volume of water held in storage, plus the expected minimum inflow based on historical records for the 11 to 24-month period.

As of 1 July 2019, the total amount of water available in Burrendong Dam was 94,000 ML (active 60,000 ML). Added to this was the expected minimum inflow over the planning horizons of 11-months of 21,000 ML and 23-months of 254,000 ML. In addition, potential bulk water transfers of about 40,000 ML from Windamere Dam were also available as resources.

Commitments for the planning horizon of 11-months were about 100,000 ML of remaining general security carryover allocations; 71,000 ML of carryover environmental water allowance; about 23,000 ML set aside for higher security entitlements (Town Water, Domestic and Stock, and High Security); 26,000 ML for storage evaporation; and 141,000 ML for essential supplies being running of the river to the end of May 2020, including delivery of replenishment flows and river losses.

The assessment was checked for the planning horizon of 23-months with the additional 23,000 ML set aside for higher security entitlements and additional storage evaporation of 26,000 ML and additional 140,000 ML for essential supplies and losses in 2020-21.

The total available resources amounted to 121,000 ML for an 11-month planning horizon and 354,000 ML for a 23-month planning horizon. The commitments totalled 361,000 ML for an 11-month planning horizon and 550,000 ML for a 23-month planning horizon. This has resulted in deficits of 240,000 ML for 11-months and 196,000 ML for 23-months respectively.

The resource assessment confirmed that the Macquarie River would cease to flow downstream of Burrendong Dam in November 2019 if there are very little inflows to the system as projected and in the absence of any drought contingency measures and drought response works.

As a result of the current drought conditions, the relevant WSP for the Macquarie and Cudgegong Regulated River has been partly suspended under the Water Management Act 2000, shifting the priorities from environmental water to critical human water needs in relevant stretches of the river subject to the suspension order.

An assessment was completed on 1 August 2019 to identifythe deficit in dam inflows for a new Available Water Determination on 1 September and it was found that the deficit in dam inflows were about 346,000 ML. The assessment was based on the total amount of water available in Burrendong Dam on 1 August 2019, which was 92,000 ML. Added to this was the expected minimum inflow over the planning horizon (September 2019 to May 2021) and potential bulk water transfer from Windamere Dam of 136,000 ML. Commitments for the planning horizon were then subtracted to find the deficit in inflows for AWD) announcement. This assessment is replicated in the opposite charts and table.

9 Resource Distribution and Drought Restrictions (August 2019 to May 2021) Resource Distribution and Drought Restrictions (August 2019 to May 2021)

35,000 64,000 General Security Irrigation Drought Account

General Security E-water* Drought Account 33,000

Planned Environmental Water 32,000 Planned Environmental Water, Drought Account

High Security 37,000

Local Water Utilities + Domestic and Stock 277,000 15,000 Evaporation from Storage 30,000 Essential Requirements and Losses

Inaccessible Storage 51,000

Total Resource: 574,000 ML * indicative breakdown of held environmental water holdings (OEH, CEWH)

Resource Distribution (August 2019 to May 2021) Volume ML Volume ML Total Available Resource 228,000 less Carryover remaining in accounts 97,000 Planned Environmental Water 69,000 Towns, Stock, Domestic 30,000 (80%) Inaccessible Storage 35,000 High Security 15,000 (70%) General Security 2019/2020 AWD 0 (0%) Essential Requirements (transmission, operations) 277,000 Evaporation from Storage 51,000 equals Water available for allocation (or deficit) (346,000)

Supply Source

250,000

200,000 Minimum inflows and Bulk water transfer, 136,000 ML

150,000

olumes (ML) 100,000 V

Burrendong Dam, 92,000 ML 50,000

0

Burrendong dam Minimum Inflow & Bulk water transfer

10 Commitments & Shortfall 1,000,000

Shortfall 346,000 ML

800,000

700,000

600,000 Storage evaporation 51,000 ML 500,000 Essential Requirements 277,000 ML

400,000 olumes (ML) V 300,000 High Security 15,000 ML

200,000 Dead Storage 35,000 ML Town water, S&D 30,000 ML 100,000 Planned Env Water 69,000 ML Carryover 97,000 ML 0

Carryover Planned Environmental Water Town water, S&D Dead Storage High Security Essential requirements (transmission, operations) Storage evaporation Shortfall

Water resource forecast

Macquarie Catchment - past 24-month rainfall

Over the last 24-months, the total rainfall across the Macquarie catchment was in the range of 800 mm to 1200 mm, which is the lowest on record. The median annual rainfall across the Macquarie catchment is 600-1,000 mm per year.

Total NSW rainfall (mm) for 24 months - 1 October 2017 to 30 September 2019

11 NSW rainfall deciles for 24 months - 1 October 2017 to 30 September 2019

Burrendong Dam - past 24-month inflows/statistical inflows

The inflows for last the 24-months were 91,000 ML which is lower than the minimum observed historic flows of 258,000 ML.

Burrendong dam past 24-month inflows/statistical inflows

3,000,000

2,500,000

2,000,000

1,500,000

1,000,000 Inflows (ML)

500,000

0

Jul-17 Jul-18 Aug-17Sep-17 Oct-17 Nov-17 Dec-17 Jan-18Feb-18 Mar-18 Apr-18May-18 Jun-18 Aug-18Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19May-19 Jun-19

20th Percentile 50th Percentile 80th Percentile Minimum Actual

12 Windamere Dam - past 24-month inflows/statistical inflows

The inflows for last the 24-months were 9,000 ML which is lower than the minimum observed historic flows of 21,000 ML.

Windamere dam past 12-month inflows/statistical inflows

180,000 160,000 140,000 120,000 100,000 80,000 60,000

Inflows (ML) 40,000 20,000 0

Jul-17 Jul-18 Aug-17Sep-17 Oct-17 Nov-17 Dec-17 Jan-18Feb-18 Mar-18 Apr-18May-18 Jun-18 Aug-18Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19May-19 Jun-19

20th Percentile 50th Percentile 80th Percentile Minimum Actual

Three-month weather forecast

Forecasts from the Bureau of Meteorology (BoM) indicate a warmer and drier spring. BoM have indicated that the main influence on weather patterns across NSW currently is the positive Indian Ocean dipole, as sea surface temperatures in the Indian Ocean impact rainfall and temperature patterns over Australia. Cooler than average sea surface temperatures can provide less moisture for frontal systems and lows crossing Australia. Generally, this means there is less moisture than normal in the atmosphere to the northwest of Australia. This changes the path of weather systems coming from Australia’s west, often resulting in less rainfall and higher than average temperatures over parts of Australia during winter and spring. Events usually start around May or June, peak between August and October, and then rapidly decline when the monsoon arrives in the southern hemisphere around the end of spring. The figure below shows that there is a 25-40% probability of the Macquarie Valley receiving above average rainfall during spring.

Bureau of Meterology, Issued: 12 September 2019.

13 Burrendong storage forecast

While rainfall over spring is forecast to be below average, weather patterns can change - especially over summer where northern NSW can see increased rainfall with the northern monsoonal season.

The figure below demonstrates the behaviour of Burrendong Dam under different inflow conditions through to June 2020.

Burrendong Dam forecast storage volume - Chance of Exceedance

140%

120%

100%

80%

60% Storage capacity (%) 40%

20%

0%

Jul-16 Jul-17 Jul-18 Jul-19 Sep-16Nov-16 Jan-17 Mar-17 May-17 Sep-17Nov-17 Jan-18 Mar-18 May-18 Sep-18Nov-18 Jan-19 Mar-19 May-19 Sep-19Nov-19 Jan-20 Mar-20 May-20

WET 20% COE Median 50% COE DRY 80% COE Minimum Actual

Under wet conditions (dark blue line) with 20th percentile inflows (meaning flows that are expected to exceed in only 2 years out of 10), the dam may reach 749,000 ML (62%) by the end of June 2020.

Under median conditions (light blue line) with inflows expected to exceed 5 years out of 10, the storage is likely to exceed 21% capacity by June 2020.

A dry scenario (green line), where conditions are expected to exceed this inflow 8 years out of 10, would still see the storage maintained to above 5.9% capacity by June 2020.

The forecast under a repeat of minimum inflow (grey) conditions indicates that Burrendong Dam will reduce closer to deep storage (inactive storage) by end of April 2020 before reaching about 4.5% of capacity by June 2020.

While the short-term forecast is for dry conditions to continue through to summer, a change in weather patterns could see conditions improve quickly.

14 Annual operations Operational Rules

Replenishment flows

1. The following replenishment flows shall be made when required and when water is available from uncontrolled flows: a. up to 10,000 ML/year to the Gum Cowal/Terrigal system, b. up to 4,000 ML/year to Crooked Creek below Mumblebone, c. up to 1,000 ML/year to the Bogan River, from Nyngan to the Gunningbar Creek , d. up to 1,000 ML/year to Beleringar Creek, downstream of Albert Priest Canal, e. up to 1,500 ML/year to Reddenville Break, and f. up to 5,000 ML/year to Beleringar Creek.

The replenishment requirements may vary considerably from year to year due to the seasonal conditions. The volumes are what is necessary to replenish the entire river length in dry antecedent conditions.

2. The following replenishment flows may be made available when required: a. up to 15,000 ML/year to Marra Creek, from its offtake, downstream to its junction with the Barwon River, and b. up to 15,000 ML/year to the lower Bogan River, downstream of its junction with Gunningbar Creek to its junction with the Barwon River.

3. Sufficient volumes of water shall be set aside from assured inflows to this water source and reserves held in Windamere Dam and Burrendong Dam water storages to provide for replenishment flows

4. A replenishment flow of up to 50 ML/day shall be provided below the Macquarie Marshes, from “Miltara” to the Barwon River, at least twice each water year.

5. Whenever possible, inflows entering the water source from tributary streams downstream of Burrendong Dam shall be used to provide replenishment flows.

Bulk transfer rules between storages

1. Bulk Water Transfer (BWT) releases shall be provided from Windamere Dam in sufficient time to prevent the storage volume of Burrendong Dam becoming insufficient to supply downstream basic landholder rights, access licence water allocations, the environmental water allowance for the Macquarie River and to meet any water losses associated with the delivery of that water. This need is determined by monthly resource assessments.

2. Resource Assessments must indicate the total volume and latest date by which transfers can be made to fulfil downstream requirements.

3. Resource Assessments must set aside sufficient reserves in Windamere Dam to provide Cudgegong Regulated River requirements through the worst period of low inflows into this water source (based on historical flow information held by the Department when the 2004 WSP commenced) at the completion of the BWTs. The current reserve is 70,000 ML.

4. Resource assessments must consider the maximum likely usage in the Cudgegong Valley. This is currently 10,000 ML/year.

15 5. Resource Assessments must consider the volume in Burrendong and Windamere Dams that is unable to be accessed (deep storage).

6. The active component of the Environmental Water Allowance is deemed to be held in Burrendong Dam, unless otherwise agreed to in writing by the Department of Primary Industries, Planning & Environment – Water.

7. Within the period November to January, releases from Windamere Dam must not exceed 500 ML/day plus orders and losses, unless agreed in consultation with the Cudgegong Valley Water Committee.

8. Releases must consider channel capacities of 1,200 ML/day at Rocky waterhole and 2,000 ML/day at Riverlea Road.

9. Windamere Dam valve capacity limits releases to no more than 2,500 ML/day (at FSL).

10. Recommended flow rates may change to optimise outcomes for the environment following consultation with Cudgegong water users and the community.

Airspace operation rules Airspace operation of Burrendong Dam shall be undertaken in accordance with the following rules:

a. When not in flood operation, releases from Burrendong Dam Flood Mitigation Zone (FMZ) should be made to provide beneficial flooding for the regulated Macquarie River, the Macquarie Marshes, Marebone floodplain and effluent creeks. The sharing and distribution of FMZ releases should be to: i. the Macquarie River and Macquarie Marshes when flows at Warren are less than 4,000 ML/day, ii. the Macquarie River and Macquarie Marshes, and Marebone floodplain, then Crooked, Gunningbar and Duck Creeks when flows at Warren are between 4,000 and 12,000 ML/day, iii. the Macquarie River and Macquarie Marshes, and Warren floodplain, then Crooked, Gunningbar, Duck, Ewenmar and Beleringar Creeks when flows at Warren are greater than 12,000 ML/day b. The FMZ operation shall where possible, place emphasis on making controlled releases during the flood event so that the storage does not increase. Note: This attempts to balance the benefits of providing airspace in Burrendong Dam to mitigate large inflow events with the damages of controlled releases that can extend the duration of flooding on the Warren floodplains. c. releases from the FMZ will vary according to the storage level, rate of inflow and the need to maintain airspace to capture likely future storage inflows, and therefore the storage shall be divided into three bays, d. each bay shall have different maximum rates of releases, and these releases which are above water orders, shall be equal to the inflow up to the maximum combined release, plus downstream tributary flow, and these releases shall be in accordance with the following: i. bay 1—Burrendong Dam water storage between 100% and 120%, and releases to a maximum of 5,000 ML/day at Warren, which equates to approximately 5.5 m at Warren town, ii. bay 2—Burrendong Dam water storage between 120% and 130%, and releases to a maximum of 12,000 ML/day at Gin Gin, which equates to approximately 6.5 m at Warren town, and

16 iii. bay 3—Burrendong Dam water storage between 130% and 142%, and releases to a maximum of 18,000 ML/day at Gin Gin, which equates to the minor flood level of 7.5 m at Warren town, e. release rates lower or higher than those indicated in subclause (1) (d) for each FMZ bay may be made if: i. the release rate specified in subclause (1) (d) will cause prolonged inundation of the floodplain and result in economic losses to agriculture, ii. the release rates specified in subclause (1) (d) will restrict landholder access to their properties for extended periods, or iii. the environment and community would benefit from lower or higher rates of release, and f. releases from the FMZ can be used to provide access to water under regulated river (High Security) access licences, regulated river (General Security) access licences and Supplementary Water access licences.

Deliverability

The following figure shows a depletion curve for Burrendong Dam considering zero inflows to the dam, and zero downstream tributary flows.

It indicates that at the end of May 2020, there will be cease-to-flow conditions from Burrendong Dam as the dam reaches deep storage level.

While the use of the zero-inflow scenario is extremely conservative, the very dry catchment and the significant depletion of soil moisture across the catchment, the use of this extreme scenario is justified.

17 Notes on the Macquarie Valley forecast storage volume: The forecasted scenario on the opposite page (page 17) is based on the end of July 2019 assessment and considers: • Incident Response Guide (IRG)-stage 4 operation • nil access to General Security (GS) and Environmental Water Allowance (EWA) from 1 July 2019 • river operates to Warren • 80% Available Water Determination (AWD) for stock and domestic users • 80% AWD for Local Water Utility users • 70% AWD for regulated high security users • 35% AWD for high security (research) • Around 25,000 – 28,000 ML bulk water transfer (i.e. Burrendong is at over 0.8% during the transfer) • 20,700 ML deep storage • 6,000 ML remains for water quality issues and fish reserve.

Critical human needs

Water is being managed in the Macquarie to meet critical human needs with a number of major centres reliant upon surface water. The Macquarie River will be managed to stop flows at Warren Weir to secure water for major town centres, including Wellington, Dubbo, Warren, Nyngan and Cobar. Domestic use downstream of Warren and in the regulated creeks will be managed through tributary inflows downstream of Burrendong Dam. In other cases, where landowners are reliant on the river for domestic use subsidised access to water carting will be available.

Critical environmental needs

The freshwater environment of the Macquarie Valley is comprised of a range of aquatic habitats, including extensive in-stream pools, and the Macquarie Marshes.

WaterNSW, in partnership with Department of Planning, Industry and Environment - Energy, Environment and Science, will be identifying critical habitat along the Macquarie River and establishing a monitoring program to assess the health of these sites during the drought.

Based on the monitoring program results, water entering the Macquarie from downstream tributaries will be managed to protect the health of critical environmental habitat. Where these sites are identified to be at risk, protection of extraction through the implementation of temporary water restrictions in the tributaries will be applied to ensure water reaches these systems. Tributary flows will be passed through the temporary works in the system to ensure the water in pools are refreshed and filled. Please see Appendix 2 of the Macquarie Drought Temporary Works Operations Management Plan for the Tributary Flow Management Plan.

Basic Landholder Rights & Domestic and Stock

Under the Water Management Act 2000, extraction of water for Basic Landholder Rights (BLR) does not require a licence, although in the case of accessing groundwater under BLR the water supply work must still be approved. BLR includes water for stock and domestic purposes extracted from a water source fronting a landholder’s property or from any aquifer underlying the land.

The taking of water for domestic purposes by persons exercising basic landholder rights, and the taking of water for domestic purposes or essential town services authorised by an access licence is the second priority under the Act.

18 The taking of water for stock purposes by persons exercising basic landholder rights, and in the case of regulated rivers, the taking of water for purposes (other than domestic purposes) authorised by a regulated river (high security) access licence is the forth priority.

Scenarios

Inflow scenarios and management outcomes:

1. Inflow event upstream of Burrendong Dam i. Any upstream event of Burrendong Dam will be captured in the storage to continue to support critical human needs along the Macquarie. ii. The temporary structures will remain in place while the Department of Primary Industries (DPI) Combined Drought Indicator (CDI) indicates a condition of drought within the Bogan, Warren, Narromine and Western Plains Regional Local Government Areas. The temporary structures will be removed within four months of all the areas no longer being in drought, as identified by the DPI CDI.

2. Small tributary inflows downstream of Burrendong i. Small events will be protected to meet critical human and environmental needs including Basic Landholder Rights (BLR) and stock and domestic use within the regulated river and creek systems downstream of Warren. Depending upon the timing of tributary events and size the specific creek system to receive flows will be dependent upon environmental monitoring outcomes.

3. Medium tributary inflows

i. Medium events will be protected to meet critical human and environmental needs including BLR and stock and domestic use within the Macquarie Valley, if they are identified as being in a critical state. 4. Large tributary inflows i. Where downstream systems (Barwon-Darling) have been identified to have critical human and/ or environmental sites at risk, large flows will be protected to provide connectivity flows to these systems. ii. Supplementary flows access may be provided as per the Water Sharing Plan rules to Macquarie supplementary access licence holders if the flow is not required to meet critical needs in the Valley and is not likely to provide a connectivity flow in the Barwon-Darling.

19 Deliverability of ordered water River Section Licence Category Type of restriction Period of Method of placing applicability water order Burrendong Dam All licence Unrestricted Until further notice iWAS and to Warren Weir categories delivery of customer help account water. desk. Water orders to be placed as normal.

Burrendong Dam Local Water Utility Unrestricted Until further notice iWAS and to Warren Town delivery of customer help Weir (ESID: 2159) account water. desk. Water orders to be placed as normal. Warren Weir to All licence Delivery of Until further notice Only via customer Marebone Weir categories account water help desk. only with tributary flows and not with Confirmation dam releases. of water order from WaterNSW is Water order is required. required and needs to be approved by WaterNSW.

Downstream of All licence Delivery of Until further notice Only via customer Marebone Weir categories account water help desk. only with tributary flows and not with Confirmation dam releases. of water order from WaterNSW is Water order is required. required and needs to be approved by WaterNSW. Downstream of All licence Delivery of Until further notice Only via customer Marebone Break categories account water help desk. and Bulgeragar only with tributary Creek flows and not with Confirmation dam releases. of water order from WaterNSW is Water order is required. required and needs to be approved by WaterNSW. Gunningbar All licence Unrestricted Until further notice iWAS and Creek offtake to categories delivery of customer help Gunningbar Weir account water. desk. Water orders to be placed as normal.

20 Gunningbar Weir All licence Unrestricted Until further notice iWAS and to Bogan River categories delivery of customer help confluence account water. desk. Water orders to be placed as normal. Downstream All licence Delivery of Until further notice Only via customer of Duck Creek categories account water help desk. offtake only with tributary Confirmation flows and not with of water order dam releases. from WaterNSW is Water order is required. required and needs to be approved by WaterNSW. Downstream of All licence Delivery of Until further notice Only via customer Crooked Creek categories account water help desk. offtake only with tributary Confirmation flows and not with of water order dam releases. from WaterNSW is Water order is required. required and needs to be approved by WaterNSW.

Trade restrictions River Section Licence Category Type of restriction Period of applicability Macquarie River General security Trading from general security licences Until further notice in the Macquarie River to any licences in Macquarie or Cudgegong rivers is suspended Macquarie River High security and Trading is unaffected Until further notice supplementary licences Cudgegong River All licence Trading of allocations is suspended Until further notice to Macquarie categories River Macquarie River High security and Trading is unaffected Until further notice to Cudgegong supplementary River licences

21 Critical dates

Date Action August 2019 Warren weir is temporarily raised 19 November 2019 Cease to flow – Macquarie River (zero inflow) – no measures enacted December 2019 Windamere Dam bulk transfer March 2020 Deep storage pumping into river May 2020 Cease to flow – with measures in place. Warren to Nyngan. May 2020 Groundwater options in place November 2020 Cease to flow – Dubbo only. Scenario One

Note: The above forecasted critical dates are based on the 30 August 2019 assessment.

Projects

The following options can be considered as emergency response plans for drought management in Macquarie Valley:

1. Raising the operating level of Warren Weir 2. Installing temporary structures to block flow downstream of Crooked Creek and Duck Creek 3. Bulk water transfer from Windamere Dam to Burrendong Dam 4. Accessing deep storage in Burrendong Dam

22 Operations Management Plan: Temporary Structures at Warren Weir, Crooked and Duck Creek

1. Overview

WaterNSW operates and maintains dams, weirs and ancillary structures across the Macquarie and system in western NSW to deliver water to customers. WaterNSW also works with the Department of Planning, Industry and Environment Water Division (DPIE-Water) to assess drought conditions and determine whether it is necessary to reduce water allocations to licence holders.

The Macquarie River Catchment is regulated to mitigate flooding and supply water to cities and towns that include Dubbo, Wellington, Narromine, Warren, Nyngan and Cobar. The main water storages in the catchment are Lake Burrendong which is on the Macquarie River, upstream of Wellington, and Lake Windamere which is on the Cudgegong River upstream of Mudgee.

Water to the town of Nyngan is supplied from the Bogan River, which flows intermittently, and from water transferred from the Macquarie River via the 67 kilometre long Albert Priest Channel. Cobar is supplied largely from the Macquarie River via the Albert Priest Channel. Water is piped to Cobar from the Bogan River weir pool at Nyngan. The Albert Priest Channel has its offtake at the Gunningbar Creek which is an effluent stream of the Macquarie River at Warren.

WaterNSW, local water utilities (Councils) and DPIE-Water are jointly and individually planning to implement a range of projects and actions in stages to provide emergency water supplies to affected communities under Stage 4 drought conditions. This includes implementing temporary works to supply water to communities that rely on surface water delivered from Burrendong Dam, including Nyngan and Cobar.

1.1 Overview of Operating Structures

WaterNSW installed temporary works at existing structures to enable water to continue to be diverted from the Macquarie River at Warren to supply Nyngan and Cobar. These works are as follows:

ƈƈ Temporarily raising the operating level of the Warren Weir by 250 mm by installing drop boards (weir level raised by 500 mm), ƈƈ Temporarily installing drop panels to block flow through fishways at the Duck Creek Regulator and Crooked Creek Regulator, and ƈƈ Temporarily close existing fishway gates at Warren Weir, Gunningbar Creek Regulator, and Marebone Regulator

Raising the operating level of the weir and blocking flow through the Warren Weir, Duck Creek Regulator, Crooked Creek Regulator, and Gunningbar Creek fishways will raise the level of the weir pool to enable water to be delivered to Nyngan via the Albert Priest Channel offtake on Gunningbar Creek.

23 2. Management of Operations of Temporary Structures

2.1 Normal Drought Operations

The following outlines operational management of the temporary structures during the period that the Macquarie remains in drought, which is identified as while the NSW Department of Primary Industries Combined Drought Indicator (CDI) (https://edis.dpi.nsw.gov.au/) indicates a condition of drought within the Bogan, Warren, Narromine and Western Plains Regional Local Government Areas.

2.1.1 Warren Weir Temporary Raising and Fishway

The temporary structure and adjoining fishway will be operated as such:

ƈƈ Warren weir shutters will be kept in place ƈƈ Warren fishway exit gate will be kept shut other than for replenishing Warren Town Weir for Town Water Supply on an as-required basis ƈƈ Flows from the dam releases will be reregulated through Warren weir pool into Gunningbar Creek

2.1.2 Duck and Crooked Creek Fishways – Temporary Blocks

The temporary structures and nearby offtake regulators will be operated as such:

ƈƈ Duck and Crooked creek offtake regulators will remain shut ƈƈ Duck and Crooked creek fishways will remain shut

2.1.3 Gunningbar Creek Offtake Regulator and Gunningbar Weir Fishway

The existing Gunningbar Weir fishway and existing Gunningbar Creek offtake regulator will be operated as such that:

ƈƈ Gunningbar Creek offtake regulator will be operated to divert flows required to meet the APC and Tritton demands and the associated losses. ƈƈ Gunningbar Weir pool level will be maintained to enable diversion into APC at the max possible rate of 50 ML/d. ƈƈ The regulators and fishway exit gate at Gunningbar Weir will be operated to maintain adequate flows in the downstream to meet Tritton’s daily demand and the associated losses.

• Flows < 30 ML/d - Gunningbar fishway may be fully closed and water delivered downstream via regulator gates. • Flows > 30 ML/d - Gunningbar fishway will be utilised as the first option for water delivery and should be fully open for the duration of delivery.

2.2 Abnormal Drought Operations

2.2.1 Excess Flows

Regulated river operations are conducted using the daily operational model CAIRO. Dam releases are conducted only to meet downstream requirements by making allowances for any tributary inflows. Excess flows are not anticipated from normal regulated operations other than during rain and increase of tributary inflows, refer Section 2.2.2.

Small excess flows arriving at Warren Weir from normal regulated operations or small tributary flows within regulated demand but are likely to overtop structures will be managed as follows:

24 ƈƈ If Marebone Weir pool is not full, excess flows may be regulated through the Warren Weir fishway to fill the Marebone Weir pool in consultation with DPIE (BCD) and NSW Fisheries ƈƈ Remaining excess flows will be regulated downstream of the Gunningbar Weir The temporary structures are designed to be able to be overtopped, however if sufficient warning of a severe overtopping event is given then the dropboards will be removed.

2.2.2 Tributary Flow Management

Under the scenario that tributary flows occur in the Macquarie River downstream of Burrendong Dam, the structures will be operated as per Appendix 1 Tributary Flow Management Plan which was agreed with NSW Fisheries and DPIE (Biodiversity and Conservation Division).

2.3 Returning to regulated operations

Once the drought conditions return to Stage 3 the system will return to regulated operations and fishways will be re-opened. Refer to 4. Decommissioning for information on when the temporary structures will be decommissioned.

3. Environmental Mitigation Measures

The sustained drought conditions have meant that critical human water needs have been prioritised and the partial suspension of the Macquarie-Cudgegong Water Sharing Plan (WSP) has meant that environmental flows have ceased under normal operation of the Regulated Macquarie catchment.

First preference for passing any tributary flows downstream will be through the fishways, and the fishways will ideally be fully opened as opposed to partially opened to promote fish passage.

3.1 Water Quality Monitoring

WaterNSW will undertake water quality monitoring in the weir pools at Warren Weir, Duck Creek Regulator and Crooked Creek regulator, as well as in selected pools downstream of Warren. This will be in accordance with Appendix 2 Water Quality Monitoring Plan.

3.2 Fish Monitoring

NSW Fisheries will undertake fish monitoring in the weir pools at Warren Weir, Duck Creek Regulator and Crooked Creek regulator, as well as in selected pools downstream of Warren. Monitoring, triggers, actions and outcomes are to be established and undertaken by NSW Fisheries.

3.3 Aeration

In order to best maintain water quality in the depleting pools WaterNSW, in consultation with NSW Fisheries, will install aeration units at several locations which are identified inAppendix 2 Water Quality Monitoring Plan.

4. Decommissioning

The works are approved under ISEPP cl 129 (3) as temporary works for or associated with drought relief are temporary and as such, the proposed temporary structures will remain in place while the DPI Combined Drought Indicator (CDI) indicates a condition of drought within the Bogan, Warren, Narromine and Western Plains Regional Local Government Areas (LGAs). The temporary structures will be removed within four months of all the areas no longer being in drought, as identified by the DPI CDI (https://edis.dpi.nsw.gov.au/). Drought status will be considered as being removed when the CDI for the LGA is identified as Recovering.

25 The removal of temporary structures includes components such as walkways, shutters or drop boards and their supports, installed as part of the works at Duck and Crooked Creek fishways and at Warren Weir.

The concrete installed along the downstream side of the Warren Weir crest to provide additional strength to the existing weir will not to be removed as it is required to strengthen the crest regardless of the temporary works. The additional concrete left in place will not change the operation or height of the weir or increase its capacity upon a return to higher river flows. This work has been assessed and is permissible under Infrastructure SEPP Clause 127(a).

Fishways at Warren Weir, Marebone and Gunningbar Creek will also be reopened and functioning as there will no longer be a need to keep them closed.

At the point that the Macquarie drought conditions are lifted the temporary structures are to be removed in accordance with a Decommissioning Management Plan to be developed by WaterNSW prior to decommissioning.

26 Appendix 1: Tributary Flow Management Plan

1. Management of downstream tributary flows

WaterNSW’s hydrometric network includes limited monitoring of the flows in the tributaries downstream of Burrendong Dam. Tributary flows may occur in all different flow rates, volumes and durations. Active management of the individual flow event by WaterNSW will be limited by the shape of the hydrograph and the capacity of the regulating structures currently in the Macquarie River. Some tributary flows may be large enough to meet more than one of the priorities listed below in Table 1.

1.1 Macquarie-Castlereagh Incident Response Guide and prioritisation of supply

The NSW Extreme Events Policy introduces a staged approach to managing extreme events such as severe droughts or poor water quality events, and to the associated Incident Response Guides (IRGs).

During normal operating conditions Tables 1.1 and 1.2 of the Macquarie–Castlereagh IRG state the priorities that apply to the distribution of water. The water allocations for higher priority licences are to be diminished at a lesser rate than the water allocations of lower priority licences.

Following the suspension of parts of the Water Sharing Plan made under s49B, the priorities are as per the Water Management Act section 60(3A). Table 1 below indicates that the first priority is to supply water to meet critical human needs. The water needs of the environment become the third priority.

Table 1 - Water Management Act priorities under s60 (3A)

Take Type/use Priority • The first priority is to be given to meeting critical human water needs First • The taking of water for domestic purposes by persons exercising basic landholder Second rights; and • The taking of water for domestic purposes or essential town services authorised by an access licence. • Needs of the environment Third • The taking of water for stock purposes by persons exercising basic landholder rights; Fourth and • In the case of regulated rivers, the taking o water for purposes (other than domestic purposes) authorised by a regulated river (high security) access licence; and • The taking of water for purposes of supply of commercial and industrial activities authorised by a major utility access licence or local water utility access licence, subject to the water made available being in accordance with any drought management strategy established bu the Minister for that purpose; and • The taking of water for the purposes of electricity generation authorised by a major utility access licence (not applicable in the WRPA);and • The taking of water for purposes authorised by a domestic and stock access licence or by persons exercising any other water rights in relation to stock; and • The taking of water for purposes authorised by a conveyance access licence in connection with the supply of water for any other purpose or need referred to in this paragraph (not applicable in this WRPA). • Taking of water for purposes authorised by any other category or subcategory of Fifth access licence.

27 1.2 Principles for managing tributary flows

The NSW Extreme Events Policy introduces a staged approach to managing extreme events such as severe droughts or poor water quality events, and to the associated Incident Response Guides (IRGs).

The following principles would apply when managing tributary flows and would be consistent with order issued under section 49B of the Water Management Act 2000, Macquarie-Cudgeong River Operations Stakeholder Consultation Committee (ROSCCo) recommendations, and consultation with government agencies:

ƈƈ Tributary flows are managed adaptively.

ƈƈ Deliver current restricted regulated demands by reducing dam releases.

ƈƈ Restore flows in regulated sections that are stopped to allow access to Basic Landholder Rights (BLR) and to meet the critical needs of the environment in those locations.

ƈƈ Divert flows to ‘dam-supported’ Stock & Domestic (S&D) replenishments, if not completed already.

ƈƈ Divert flows to ‘tributary only’ S&D replenishments – by matching available volume and duration with needs.

ƈƈ Deliver supplementary events when triggered as per Water Sharing Plan rules after allowing for higher priority requirements.

ƈƈ Progressively divert flows from highest priority environmental needs to lower priority environmental demands, based upon water demand assessments arising from near-real time monitoring undertaken by various agencies participating in the Macquarie vTAG, lead by DPIE Fisheries (see App 1 Section 2 below).

1.3 Heads of Consideration

The following heads of consideration would apply when determining how tributary flows are to be managed:

ƈƈ Water Management Act S60 (3A) while an order under section 49B is in force

ƈƈ WMA s324 (1) order suspension of remaining carryover allocations in general security accounts in the Macquarie River including environmental licences (page 2251); (https://gazette. legislation.nsw.gov.au/so/download.w3p?id=Gazette_2019_2019-66.pdf)

ƈƈ WMA s49B suspension of operations of planned environmental flow rules (https://gazette. legislation.nsw.gov.au/so/download.w3p?id=Gazette_2019_2019-69.pdf)

ƈƈ Restrictions to water delivery in the Macquarie River as per operations update: (https://www. waternsw.com.au/__data/assets/pdf_file/0020/145280/Macquarie-Operations-Update-1- July-2019.pdf)

1.4 Governance

Decision making on distribution of tributary flows during any events is by WaterNSW system operations manager after considering legislated priorities. Consultation regarding management of tributary flows would involve the following representatives:

ƈƈ WaterNSW Water system operations manager

ƈƈ DPIE Biodiversity and Conservation North West Branch Senior Wetlands and Rivers Conservation Officer

28 ƈƈ DPIE Fisheries Senior Fisheries Manager – Western

WaterNSW will also seek recommendations from the broader group of stakeholders via the Macquarie-Cudgeong River Operations Stakeholder Consultation Committee (ROSCCo).

Table 2 - Indicative adaptive management of tributary flows

Structure Capacity River Flow Level Trib Flow 1: Up to 400 (ML/d) Trib Flow Level 2: Above 400 (ML/d) (ML/d) (175 ML/d)

Scenario 1 Scenario 2 Option Option Option Option Option Option Option Option Option Option (cooler (warmer 1 2 3 4 5 1 2 3 4 5 months) months)

Downstream of Warren 9,800 minor 0 0 0 85 0 25 155 over over over over over Weir (oversill) flood level 25 100 25 50 160 Warren Weir Fishway 25 25 0 0 25 25 25 25 25 25 25 25 25 Gunningbar Creek >1500 d/s 150 175 400 290 375 350 220 400 290 375 350 220 offtake Regulator channel capacity Trans losses Gunningbar 10-50 20 50 50 50 50 50 50 50 50 50 50 50 offtake - Gunningbar Weir Gunningbar Creek 400 d/s 40 75 300 80 70 45 80 300 150 70 45 20 downstream weir channel capacity Albert Priest Channel 50 50 50 50 50 50 50 50 50 50 50 50 50

Duck Creek regulator 70-100 0 0 0 35 95 95 0 0 0 95 95 25 d/s env channel capacity Duck Creen Fishway 25-30 25 0 0 25 30 30 25 0 25 30 30 25 Crooked Creek 80 offtake 0 0 0 35 60 60 0 0 0 60 60 35 Regulator Crooked Creek Fishway 15-20 15 0 0 15 20 20 15 0 15 20 20 15

2. Environmental risk factors to be considered

Critical environmental needs are defined as ‘avoiding irrevocable damage to environmental assets or values.” Practically, this involves two key specific items: 1. Survival of native fish within drought refuges 2. In the event of extended drought, avoiding critical drying thresholds of long-lived vegetation in the Macquarie River riparian areas and Macquarie Marshes – primarily River Red Gum woodlands and forests, recognizing not all areas can be reached with smaller flows.

Known drivers of fish survival in pools based on observations of other recent environmental flow events in the northern basin include: 1. Timing, flow rate and water quality of imminent flows – antecedent temperatures (high heat, sudden temperature drops), are the flows sufficient to de-stratify or heat up pools, hypoxic water or likely high Biochemical Oxygen Demand. 2. Status of river pools at the time a. Stratification (yes/no) b. Depth/volume within the pool (carrying capacity) c. Water quality of the pool (dissolved oxygen, salinity, hypoxic blackwater) d. Fish biomass (carrying capacity), if known e. Biomass of algae and cyanobacteria (risk of fish death upon destratification)

29 There is the potential for tributary flow releases to alter water quality in downstream waterways. The viability of effectively topping up of river refuge pools through tributary flows will be based on real- time assessments from: 1. on-ground monitoring. It is proposed to identify the overall risk of drought refuge pools on a fortnightly basis over warmer months October to March, and monthly in other times. This will be dependent on the creation of a short-term intervention monitoring program between NSW and Commonwealth agencies. 2. In the absence of information from on-ground monitoring, flow thresholds as listed in the Macquarie–Castlereagh Long Term Water Plan (draft, DPIE BCD) and anecdotal evidence may be considered.

3. Addendum

Water Management Act 2000 s60 (3A) While an order under section 49B is in force, the following rules of distribution apply to the making of an available water determination: a. first priority is to be given to meeting critical human water needs,

b. second, third, fourth and fifth priorities are to be given to the matters set out in subsection (3) (a), (b), (c) and (d), respectively, to the extent that those matters are not critical human water needs.

S60 (3C) In this section: critical human water needs mean the needs for a minimum amount of water, that can only reasonably be provided from the Basin water resources, required to meet: a. core human consumption requirements in urban and rural areas, and

b. those non-human consumption requirements that a failure to meet would cause prohibitively high social, economic or national security costs.

30 Appendix 2: Water Quality Monitoring Plan

1. Monitoring Program

1.1 Background

As part of the REF approvals process relating to this project, WaterNSW has agreed to undertake water quality monitoring of critical refuge pools created by the temporary raising of Warren Weir and blocking of Duck Creek, Crooked Creek and Warren Weir fishways.

1.2 Overview of program

The monitoring sites have been determined by NSW DPIE Fisheries with the support of DPIE Biodiversity and Conservation Division). Due to the number of sites and the cost of mixing the pools, it was recommended that a variety of technologies be trialled at the sites including solar powered bubble plume mixers (commonly known as aerators) and two different cyanobacterial and algal treatments as well as control treatment. WaterNSW is currently conducting a bench top trial of four different cyanobacterial and algal treatments (Aqua Cal, Water Cleaners, Barley Straw, Diatomix). After completion of the bench top trial two treatments will be selected based on effectiveness, application and cost for the refuge pool trial.

The closure of Warren, Duck and Crooked weirs will create three large refuge pools. These pools will be supplied with solar powered bubble plume mixers and will also be monitored.

1.3 Details of program

1.3.1 12no. Refuge pools downstream of Warren Weir

Bubble plume mixers and the two cyanobacterial/algal treatments will all be replicated in three refuge pools each.

The refuge pools will be monitored fortnightly from Mid-September 2019 till March 2020

Monitoring will include: ƈƈ Temperature and dissolved oxygen profiling in the deepest part of the 12 refuge pools. ƈƈ A water sample will be collected and analysed for the following: Total algae, DOC, dissolved nutrients (N oxidised, N ammoniacal, P soluble reactive), total nutrients (N total, P total)

1.3.2 2no. Refuge pools upstream of Warren Weir and Duck & Crooked Creek Regulators

Bubble plume mixers will be installed above each weir.

The weir pools will be monitored monthly from Mid-September 2019 until March 2020

Monitoring will include: ƈƈ Temperature and dissolved oxygen profiling in the deepest part of the weir pools. ƈƈ A water sample will be collected and analysed for the following: Total algae

31 2. Reporting

A report will be produced at the end of March 2020 comparing the various treatments and assess effectiveness of each in providing suitable fish habitat.

NSW Fisheries to receive ongoing water quality results as they are obtained and reported. Triggers, actions and outcomes are to be established and undertaken by NSW Fisheries.

32