Namoi Peel

Operations

Plan

July 2019

.com.au

Contents

1. Highlights ...... 3

2. storage ...... 4

2.1 storage...... 4

2.2 storage ...... 5

2.3 storage ...... 6

3. Supplementary access...... 6

3.1 Commentary ...... 6

4. Water availability ...... 7

4.1 2019/2020 water availability for Peel as of 1 July 2019 ...... 7

4.2 2019/2020 water availability for Upper Namoi as of 1 July 2019 ...... 8

4.3 2019/2020 water availability for Lower Namoi as of 1 July 2019 ...... 9

4.4 Resource assessment ...... 10

4.5 Deliverability of ordered water Namoi...... 12

4.6 Deliverability of ordered water Peel ...... 13

5. Rainfall ...... 14

6. Inflows ...... 16

7. Operational surplus ...... 22

8. Storage forecast ...... 24

9. Outage planning ...... 26

10. Prognosis ...... 27

Namoi Peel Valley Operations Plan July 2019 2

1. Highlights

 The severe and ongoing drought conditions across NSW are having a significant impact on the ability of WaterNSW to deliver water to customers.

 While allocations for the Namoi and Peel Valleys have been announced by the Department of Planning, Industry and Environment, the delivery of water is restricted due to the ongoing drought

 The Peel system is currently being operated under drought contingency measures with water delivery restrictions

 The water delivery restrictions and operational arrangements are outlined in the Sections 4.5 for Namoi and 4.6 for Peel and are specifically outlined for each river section to best assist landholders and customers with information relevant to their specific circumstances

 The Namoi delivery loss account is empty since 31 January 2018.

 A range of extra measures had to be introduced in the Lower and Upper Namoi and included restrictions on access to water and limitations to trade.

 No further releases from Keepit Dam are possible until it receive further inflows.

Namoi Peel Valley Operations Plan July 2019 3

2. Dam storage

2.1 Keepit Dam storage

The below figure shows the Keepit Dam behaviour for the 2018-19 water year compared to the last four water years.

Keepit Dam Storage 100%

90%

80%

70%

60%

50%

40%

Storage Capacity (%) Capacity Storage 30%

20%

10%

0% Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun 2014/15 2015/16 2016/17 2017/18 2018/19

From the above figure it can be seen that Keepit Dam was around 12% at the start of this water year and it is now just slightly under 2.5% of total capacity, the lowest level on record. A Bulk Water Transfer from Split Rock to Keepit was required to deliver water in the Lower Namoi. The Bulk Water Transfer was undertaken from mid-October.

Namoi Peel Valley Operations Plan July 2019 4

2.2 Split Rock Dam storage

The below figure shows the behaviour of Split Rock Dam for the 2018-19 water year compared to the last four water years.

Split Rock Dam Storage 40%

30%

20% Storage Capacity (%) Capacity Storage 10%

0% Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun 2014/15 2015/16 2016/17 2017/18 2018/19

From the above figure it can be seen that Split Rock Dam was under 15% at the start of this water year and it is now about 3% of total capacity. The change in storage levels was primarily due to the Bulk Water Transfer to Keepit Dam, with smaller reductions in level due to ongoing releases for Upper Namoi customers.

Namoi Peel Valley Operations Plan July 2019 5

2.3 Chaffey Dam storage

The below figure shows the Chaffey Dam behaviour for the 2018-19 water year compared to the last four water years, with the percentages expressed in relation to the current (enlarged) Chaffey Dam capacity.

Chaffey Dam storage 120

100

80

60

40 Storage capacity Storage capacity (GL)

20

0 Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun 2014/15 2015/16 2016/17 2017/18 2018/19

From the above figure it can be seen that Chaffey dam volume was around 55% at the start of the water year and it is now close to 25.7% of total capacity, which is lower than June in 2015.

3. Supplementary access

3.1 Commentary

Due to lack of surplus flows entering the system, there have not been any supplementary events in the Lower Namoi in the 2019/20 water year.

The last supplementary event was approved by DPI Water in September 2016.

Namoi Peel Valley Operations Plan July 2019 6

4. Water availability

4.1 2019/2020 water availability for Peel as of 1 July 2019

Licence Share Carryover AWD Allocation Allocation Usage Balance category component in volume assignments assignments in out Domestic and 77 - 53.9 0 0 0 53.9 stock Domestic and 66 - 46.2 0 0 0 46.2 stock (domestic) Domestic and 20 - 14 0 0 0 14 stock (stock) Local water utility 16,400 - 11,480 0 0 19 11,461 Regulated river 1,257 - 0 0 0 0 0 (general security environment) Regulated river 28,333 -137.7 0 0 0 3.4 -141.1 (general security) Regulated river 801 - 400.5 0 0 0.6 399.9 (high security) Regulated river 3 0 1.5 0 0 0 1.5 (high security) [research] Grand total 46,957 -137.7 11,996 0 0 23 11,835

Peel River valley AWD (ML/share, %) Licence category Date of allocation 0.00 / 00% General security 1 July 2019 0.50 / 50% High security 1 July 2019 0.70 / 70% Domestic and stock 1 July 2019 0.70 / 70% Local water utilities 1 July 2019

 Currently Chaffey Dam volume is at 25.7% of total capacity.

Namoi Peel Valley Operations Plan July 2019 7

 In this current water year, Available Water Determinations (AWD) are the equivalent of 0% for General Security (GS). For other water users (e.g. High Security and Town Water Supply), the AWD is 50% and 70% respectively. No carryover applies in the Peel.

 Further general security AWDs are possible throughout the year.

 The sum of account balance refers to the total amount of water available to licence holders after trades and usage.

4.2 2019/2020 water availability for Upper Namoi as of 1 July 2019

Licence category Share Carryover AWD Allocation Allocation Usage Balance component in volume assignments assignments in out Domestic and 74 0 74 0 0 0 74 stock Domestic and 11 0 11 0 0 0 11 stock (domestic) Domestic and 5 0 5 0 0 0 5 stock (stock) Local water utility 515 0 515 0 0 0 515 Regulated river 11,454 2,797 0 0 0 5 2,797 (general security) Regulated river 80 0 60.1 0 0 0 60.1 (high security) Grand total 12,139 2,797 665 0 0 5 3,457

Upper Namoi AWD (ML/share %) Licence category Date of allocation 0.00 / 0% General security 1 July 2019 0.75 / 75% High security 1 July 2019 1.00 / 100% Domestic and stock 1 July 2019 1.00 / 100% Local water utilities 1 July 2019

 Currently Split Rock Dam volume is at 2.2% of active storage capacity and is currently releasing around 7 ML/d for the Upper Namoi (as of 2019/07/10).

Namoi Peel Valley Operations Plan July 2019 8

4.3 2019/2020 water availability for Lower Namoi as of 1 July 2019

Licence category Share Carryover AWD Allocation Allocation Usage Balance compone in volume assignments assignments nt in out Domestic and stock 1,665 -15.6 1665 0 0 0 1,649 Domestic and stock 20 0 20 0 0 0 20 [domestic] Domestic and stock 257 0 257 0 0 0 257 [stock] Local water utility 2,271 0 2,271 0 0 0 2,271 Regulated river 13,548 447 0 0 0 0 447 (general security env) Regulated river 231,040 11,605 0 0 0 0 11,876 (general security) Regulated river (high 3,418 0 2,563 0 0 0 2,563 security) Regulated river (high 486 0 364.5 0 0 0 364.5 security) [research] Supplementary water 114,680 0 114,680 0 0 0 114,680 Grand total 367,386 12,036 121,821 0 0 0 134,129

Lower Namoi AWD (ML/share, %) Licence category Date of allocation 0.00 / 0% General security 1 July 2019 0.75 / 075% High security 1 July 2019 1.00 / 100% Domestic and stock 1 July 2019 1.00 / 100% Local water utilities 1 July 2019

 The initial Available Water Determinations (AWD) for the Lower Namoi are 100% for towns and high security, while general security is zero. Carryover into 2019-20 was estimated to be equivalent to 5% of general security share components on average.

 Currently Keepit Dam is at 1.0% active capacity and without significant inflows (around 95.7GL) no further AWD announcement will be made in 2019-20.

Namoi Peel Valley Operations Plan July 2019 9

4.4 Resource assessment

Namoi Valley resource assessment distribution 1 July 2019

12.43 10.26

0 4.56 0 2.77

20.43

0

58.24

Storage losses Storage losses shortfall Essential supplies Essential supplies shortfall Upper Namoi / Delivery losses Delivery losses shortfall General security General security shortfall

Namoi Peel Valley Operations Plan July 2019 10

Water Balance in the Namoi 1 July 2019 800

700

600 Available Airspace 693.8

General Security 0 500 Delivery Losses 0

Upper Namoi / Manilla River 2.77 400 694 Essential Supplies 0

300 Storage Losses 10.26

Dead storage 9.7

200

100

1003 0 10

4.4.1 Significance of this resource assessment

The current resource assessment at 1 March 2019 indicates that 95.7 GL of inflow is required to make up for the shortfall before any future AWD announcements are possible.

4.4.2 Resource assessment process

The Resource Assessment is the process of calculating how much water is available based on the rules of the Water Sharing Plan (WSP). This is done at the end of the month and when any significant inflow event happens. The above resource assessment table is for the planning horizon from 1 July 2019 to 30 June 2021.

Namoi Peel Valley Operations Plan July 2019 11

4.5 Deliverability of ordered water Namoi

River section Licence Type of restriction Period of Method of placing category applicability water order Upper Namoi High Security From 1 July, water shortages and or It is envisaged Only via customer (Split Rock Dam delays in the delivery of water should that limited water help desk. Orders to upstream of General be expected. deliveries will cannot be placed via Keepit) Security continue until at iWAS. Further restrictions are likely – releases least September Stock & may need to be grouped together 2019. Confirmation of water Domestic (block releases), rostering may be order from WaterNSW required, or releases may need to be WNSW will be is required. Local Water stopped. consulting with Utility customers in the A water order is still required to be coming weeks placed and needs to be approved and months by WaterNSW. about future arrangements. Lower Namoi High Security No Dam releases will be made to Until further Only via customer (downstream of supply orders or the Pian Ck notice help desk. Orders Keepit Dam to General replenishment flow. cannot be placed via Walgett) Security iWAS. Limited access may become Stock & available from tributary inflows. Confirmation of water Domestic order from WaterNSW A water order is still required to be is required. Local Water placed and needs to be approved Utility by WaterNSW.

Namoi Peel Valley Operations Plan July 2019 12

4.6 Deliverability of ordered water Peel

River section Licence Type of restriction Period of Method of placing category applicability water order Chaffey Dam to Local Water Delivery of account water will be Until further Only via customer Tamworth Utility provided from Chaffey Dam until a notice help desk. Orders temporary weir is installed in cannot be placed via High Security November (at the earliest). iWAS.

Stock & Confirmation of water Domestic order from WaterNSW A water order is still required to be is required. General placed and needs to be approved Security (zero by WaterNSW. allocation) Tamworth to High Security Limited supplies to high security and Until further Only via customer Carroll Gap stock and domestic licences will be notice help desk. Stock & provided from 1 July, however water Domestic shortages and or delays in the Confirmation of water delivery of water should be order from WaterNSW General expected. is required. Security (zero Access may become available from allocation) tributary inflows or possibly from existing river pools. A water order is still required to be placed and needs to be approved by WaterNSW.

Namoi Peel Valley Operations Plan July 2019 13

5. Rainfall

5.1 6-month rainfall

From the above figures the last 6-months of total rainfall lies is in the range of 100mm to 300mm, which is between very much below average and lowest on record.

Namoi Peel Valley Operations Plan July 2019 14

5.2 24-month rainfall

From the above figures the last 24-months of total rainfall lies in the range of 800mm to 1600mm, which is between very much below average and lowest on record.

Namoi Peel Valley Operations Plan July 2019 15

6. Inflows

6.1 Keepit Dam inflows

6.1.1 Keepit Dam - past 6-month inflows/statistical inflows

Keepit past 6 months inflows/statistical inflows 250.0

200.0

150.0

100.0 Gigalitres (GL) Gigalitres

50.0

0.0 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 minimum 80 percentile 50 pecentile 20 percentile Actual inflow

The estimated inflows for last 6 months were 3.17 GL. This inflow is higher than the minimum observed/historic flows of 0.3 GL.

Namoi Peel Valley Operations Plan July 2019 16

6.1.2 Keepit Dam - past 24-month inflows/statistical inflows

Keepit past 24 months inflows/statistical inflows 1,000.0

900.0

800.0

700.0

600.0

500.0

400.0 GIgalitres (GL) GIgalitres 300.0

200.0

100.0

0.0 Jul-17 Oct-17 Jan-18 Apr-18 Jul-18 Oct-18 Jan-19 Apr-19 minimum 80 percentile 50 pecentile 20 percentile Actual inflow

The estimated inflows for last 24 months were 121.45 GL (including 80.2 GL from two Bulk Water transfers from Split Rock Dam). The net inflow of 41.25 GL is lower than minimum observed/historic flows of 60.7 GL.

Namoi Peel Valley Operations Plan July 2019 17

6.2 Split Rock Dam inflows

6.2.1 Split Rock Dam - past 6-month inflows/statistical inflows

Split Rock past 6 months inflows/statistical inflows

60.0

50.0

40.0

30.0

GIgalitres (GL)GIgalitres 20.0

10.0

0.0 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 minimum 80 percentile 50 pecentile 20 percentile Actual inflow

The estimated inflows for the last 6 months were 0.63 GL which more than minimum observed/historic flows of 0.4 GL.

Namoi Peel Valley Operations Plan July 2019 18

6.2.2 Split Rock Dam - past 24-month inflows/statistical inflows

Split Rock past 24 months inflows/statistical inflows

250.0

200.0

150.0

100.0 Gigalitres (GL) Gigalitres

50.0

0.0 Jul-17 Oct-17 Jan-18 Apr-18 Jul-18 Oct-18 Jan-19 Apr-19 minimum 80 percentile 50 pecentile 20 percentile Actual inflow

The estimated inflows for the last 24 months were 9.97 GL which is lower than the minimum observed/historic flows of 11.1 GL.

Namoi Peel Valley Operations Plan July 2019 19

6.3 Chaffey Dam inflows / updated

6.3.1 Chaffey Dam - past 6-month inflows/statistical inflows

Chaffey Dam Past 6 months cumulative inflow/statistical inflows

45.0

40.0

35.0

30.0

25.0

20.0

Gigalitres (GL) Gigalitres 15.0

10.0

5.0

0.0 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 minimum 80%ile 50%ile 20%ile Actual inflow The estimated inflows for the last 6 months were 0.6 GL which is more than minimum observed/historic flows of 0.2 GL.

Namoi Peel Valley Operations Plan July 2019 20

6.3.2 Chaffey Dam - past 24-month inflows/statistical inflows

Chaffey Dam Past 24 months cumulative inflow/statistical inflows 180.0

160.0

140.0

120.0

100.0

80.0

Gigalitres (GL) Gigalitres 60.0

40.0

20.0

0.0 Jul-17 Oct-17 Jan-18 Apr-18 Jul-18 Oct-18 Jan-19 Apr-19 minimum 80%ile 50%ile 20%ile Actual inflow

The estimated inflows for last the 24 months were 7.9 GL which lower than the minimum observed/historic flows of 16.2 GL.

6.4 Downstream tributary inflows

There are no significant downstream tributary inflows this water year.

Namoi Peel Valley Operations Plan July 2019 21

7. Operational surplus

6.1 Operational surplus for 2018-19 Namoi

Operational surplus – defined as water delivery operational surplus vs sales - for the Namoi valley are made of combined operational losses from the Upper Namoi and the Lower Namoi.

Namoi - water delivery operational surplus vs sales - 2018-19, cumulative %

6%

5% target 5% 4%

3%

2% target 1% (block releases) 1%

0%

water delivery operational surplus vs sales %

Namoi cumulative totals Dates Sales + environmental Cumulative Actual Target delivery Operational surplus July 800 0 0% 5% July-Aug 900 0 0% 5% July-Sep 900 0 0% 5% July-Oct 9,169 0 0% 1% July-Nov 34,924 25 0% 1% July-Dec 40,200 399 1% 1% July-Jan 40,200 399 1% 1% July-Feb 40,200 399 1% 1% July-Mar 40,200 399 1% 1% July-Apr 40,200 399 1% 1% July-May 40,200 399 1% 1% July-Jun 40,600 399 1% 1%

Namoi Peel Valley Operations Plan July 2019 22

6.2 Operational surplus for 2018-19 Peel

Operational surplus – defined as water delivery operational surplus vs sales for the Peel valley

Peel - water delivery operational surplus vs sales - 2018-19, cumulative %

10% 9% 8% 7% 6% target 5% 5% 4% 3% 2% 1% 0%

water delivery operational surplus vs sales %

Peel cumulative totals Dates Sales + environmental Cumulative Actual Target delivery Operational surplus July 1,300 20 2% 5% July-Aug 2,520 40 2% 5% July-Sep 4,330 110 3% 5% July-Oct 5,750 220 4% 5% July-Nov 7,687 286 4% 5% July-Dec 9,514 987 10% 5% July-Jan 12,076 1,101 9% 5% July-Feb 13,861 1,201 9% 5% July-Mar 15,161 1,231 8% 5% July-Apr 16,362 1,231 8% 5% July-May 17,253 1,231 7% 5% July-Jun 17,800 1,231 7% 5%

Namoi Peel Valley Operations Plan July 2019 23

8. Storage forecast

8.1 Keepit storage forecast

Keepit forecast storage volume chance of exceedance 450

400

350

300

250

200

150

Storage capacity (GL)Storagecapacity 100

50

0 Jul-18 Oct-18 Jan-19 Apr-19 Jul-19 Oct-19 Jan-20 Apr-20 Jul-20 Oct-20 Jan-21 Apr-21 Minimum 99% COE DRY 80% COE Median 50% COE WET 20% COE Actual

The above figure demonstrates the behaviour of Keepit Dam under different inflow conditions through to June 2021. For example, with 20th percentile inflows, the dam may reach 425 GL (100%) and spill before the end of August 2020.

8.2 Split Rock storage forecast

Split Rock - forecast storage volume chance of exceedance 250

200

150

100 Storage capacity (GL)capacity Storage 50

0 Jul-18 Oct-18 Jan-19 Apr-19 Jul-19 Oct-19 Jan-20 Apr-20 Jul-20 Oct-20 Jan-21 Apr-21 Minimum 99% COE DRY 80% COE Median 50% COE WET 20% COE Actual

Namoi Peel Valley Operations Plan July 2019 24

The above figure indicates the behaviour of Split Rock Dam under different inflow conditions through to June 2021. For example, with 20th percentile inflows the dam may reach 200 GL before the end of June 2021. The COE in the figure refers to the chance of exceeding these conditions in the time frame. For example, Wet 20% COE indicates that there is 20% of chance that the dam volume will be better than the projected volume, and there is 80% chance that the dam volume will be less than the projected volume.

8.3 Chaffey storage forecast

Chaffey Dam - forecast storage volume chance of exceedance 100

80

60

40

20

Storage capacity (GL)Storagecapacity 0 Jul-18 Oct-18 Jan-19 Apr-19 Jul-19 Oct-19 Jan-20 Apr-20 Jul-20 Oct-20 Jan-21 Apr-21 Minimum 99% COE DRY 80% COE Median 50% COE WET 20% COE actual

The above figure demonstrates the behaviour of Chaffey Dam under different inflow conditions through to February 2021. For example, with 20th percentile inflows, the dam may reach 102 GL (100%) and spill, by the end of July 2020. The forecast under a repeat of minimum inflow conditions indicates that Chaffey Dam will reduce to a minimum of about 11% of capacity by July 2020.

Namoi Peel Valley Operations Plan July 2019 25

8.4 Next 3 months scenario from the BOM forecast

9. Outage planning

Item Time Description Chaffey dam (Peel) N/A None Split Rock dam (Upper Namoi) N/A None Keepit dam (Lower Namoi) N/A None Mollee weir N/A Fishway remedial works are planned Gunidgera weir N/A Works are planned at Gunidgera weir Knights weir N/A None Weeta weir N/A None Gunidgera regulator N/A None Knights regulator N/A None

Namoi Peel Valley Operations Plan July 2019 26

10. Prognosis

Possible General Security Allocations, for the Lower Namoi based on different inflow scenarios are as follows:

Extremely dry Dry (80th percentile Average (50th Wet (20th percentile (minimum inflows) inflows) percentile inflows) inflows) 3-month 0.0 0.0 0.0 1.7 forecast to 30-Sep -19 6-month 0.0 0.0 0.3 31.4 forecast to 31-Dec-19

If the dry conditions continue with 80th percentile inflows and 50th percentile inflows, then no AWD announcement is likely up to September 2019. If the conditions improve with 20th percentile inflows, then there is a 20% chance of an increased AWD of 1.7 % by September 2019 and 31.4 % by December 2019.

More information

Subscribe to our customer information (weekly water availability reports, e-newsletters, etc.) at waternsw.com.au/subscribe.

Namoi Peel Valley Operations Plan July 2019 27