water nsw water availability report · water nsw – water availability report ... bom’s 4 and 8...

Water Availability Report – 3 July 2017

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Water NSW – Water Availability Report

Overview

WaterNSW manages and operates 42 dams and storages to deliver water for environmental, domestic,

town water, stock, industrial and irrigation purposes across the state.

WaterNSW storages provide supplies to all of the major river systems in Western NSW, Greater Sydney,

the Southern Highlands, Shoalhaven Bay as well as the Hunter, Bega, and Iron Pot valleys in coastal

NSW.

The total active storage percentage of rural water supplies on 3rd

July 2017 was 70.5% of the total active

storage capacity. This resulted in an increase of 0.8% from last week.

The total storage level of urban water supplies on the on 3rd

July 2017 was 93.4% of the total storage

capacity. This was a 0.5% decrease from last week.

System Risks

Spills from southern and central storages are likely over the winter months with a greater than

35-55% chance of occurring.

Supply issues in a number of streams as low demand is leading to lower river heights this winter.

The Bureau's ENSO Outlook has been reset to INACTIVE after an easing of climate model

outlooks, but most models still indicate an increased chance of warmer and drier than average

conditions over winter.


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Climatic Conditions

For large parts of the southern and central districts of NSW, June 2017 was the driest on record.

Figure 1- Rainfall Deciles June 2017

During the first part of the week, a low pressure trough system crossed the state resulting in higher falls

(10-65mm) along the northern inland. The remainder of the state received little (5-10mm) or no rain.


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Figure 2- Weekly rainfall totals for New South Wales (w/e 3rd July 2017)

BOM’s 4 and 8 day forecast (figure 3a and 3b) indicates that rainfall of 1 – 50mm is forecast for the

southern part of the state, with little or no rain expected for remainder of the state.

Figure 3a - 4 day Forecast (1st 4 days) Figure 3b – 8 day forecast


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3 Month Forecast Climatic Conditions

The BOM 3 month outlook (figure 4) suggests that July to September rainfall is likely to be below average

for most of NSW.

Figure 4 - 3 month rainfall forecast

A drier than average July is likely over eastern NSW.

July to September rainfall is likely to be below average over parts of NSW

This outlook is influenced by higher than average pressure over southern Australia during July to

September.

The Bureau's ENSO Outlook has been reset to INACTIVE after an easing of climate model

outlooks, and a reversal of the early autumn warming in the eastern tropical Pacific Ocean. The

El Niño–Southern Oscillation (ENSO) remains neutral. All international climate models suggest

ENSO is now likely to remain neutral for the remainder of 2017.


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Valley Based Operational Activities

Murray Valley

Storage Status

Hume Dam is currently at 70%, releasing 2,000 ML/day.

Predicted Release Patterns

Hume releases include delivery of environmental flows.

The flow target at downstream Yarrawonga Weir is about 4,000 ML/day and is likely to vary

between 3,800 ML/day and 4,200 Ml/day

The flow target at downstream Stevens Weir remains at 300 - 350ML/day

Environmental watering events in the Murray and Edward – Wakool systems are continuing at

low rates

With the reduction in flows in the Murray River, the Edward and Gulpa offtake gates have been

lifted clear of the water, so the flow in these streams will vary with the level in the Murray.

Operating Conditions

Dam Spill Likelihood: Based on historical inflow conditions there is a 50% chance of Hume

Dam spilling by September. However, BoM is forecasting a lower than average probability of

median rainfall in the catchment this winter.

The commencing allocation for Murray Regulated River general security is 11% and carryover is

equivalent to about 42%.

Stevens Weir pool has now been lowered to 4m, and will be held at about this level to facilitate

environmental watering in the Edward-Wakool system.

Planned Supply Interruptions

None.

Lower Darling Valley

Storage Status

The lakes currently hold a total volume of about 770GL or about 40% of active capacity.


Menindee outlet releases to Darling River are currently averaging about 350 ML/d to supply

environmental orders above minimum flow targets. Pamamaroo outlet is releasing about 50ML/d.

Releases that commenced on 16 February 2017 into Darling Anabranch to meet the

environment orders of 100GL, have ceased on 30 June 2017.


Approximately 47GL of inflow has been recorded at Lake Wetherell from 1 May 2017 with

recession likely to continue beyond mid-July.


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Water is being transferred from Lake Wetherell to Lake Pamamaroo to minimise the surface area

of the stored volume.

Planning is underway with MDBA to leave enough water in the upper lakes, to secure Broken Hill

and Lower Darling supplies, based on the repeat of the worst drought on record.

The current resources are sufficient to assure full allocation for all Lower Darling licence

categories for the 2017-18 water year, including access to carryover water.


Nil

Murrumbidgee Valley

Storage Status

Burrinjuck Dam is currently at 62% releasing about 450 ML/day.

Blowering Dam is about 80% releasing about 560ML/day.


The dam releases are likely to remain close to minimum release requirements. Translucent

release rules are now applicable at Burrinjuck Dam, but inflows are also low.


A media release and a customer notice have been issued advising the community of low river

levels due to minimum releases from the dams and dry conditions in the tributary catchments.

There is sufficient stream flow in the river to meet customer orders in the system but, the river

heights are very low.

Dam Spill Likelihood: Based on historical inflow conditions there is greater than about 35%

chance of both Burrinjuck and Blowering Dams spilling by October 2017. BoM is also forecasting

a lower than average probability of median rainfall in the catchment this winter.

Planning is underway for the Wetland Reconnect watering downstream of Wagga (piggy back

event) which is most likely to be towards mid- to late- July 2017

All the lay flat gates in the Beavers Creek Offtake have been fully lowered, as per the Work

Approval conditions, to allow free fish passage. Due to low Murrumbidgee River levels, there is

negligible or no flows in the Beavers Creek/Old Man Creek over the last four weeks.

Currently diversions at the Yanco Ck off-take are about 400ML/d and likely to reduce with

reduced demands in the system. Irrigation escapes are no longer available with the winter

season close of the CICL.

There was a system shortfall in the mid-Billabong creek upstream of the Yanco – Billabong

Junction. The flows at Hartwood Weir were close to zero for a few days closer to the end of

water year as quite a few customers were suspected of extracting water without a valid water


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order. The CARM system was used to identify the customers that needed to stop extraction so

the creek could return to target flows.

Hay Weir is being handed over to the maintenance team for routine maintenance work.

Environmental watering to Lowbidgee wetlands via North Redbank channel concluded on 30

June.

The commencing allocation for Murrumbidgee Regulated River general security is 17% with

carryover close to the maximum limit of 30%..


Burrinjuck power station is offline for maintenance. However, all planned releases would be

made from the four low level valves that have a combined capacity of 9,000ML/day, which is well

above current demands. Therefore, there are no supply constraints.

Berembed Main Canal is closed. Berembed Weir is currently fully drawn down to facilitate

maintenance works and gate replacement on the Berembed Main regulator. These works are

scheduled to be complete prior to 30 July.

Gogelderie weir has been handed over to the Maintenance and Services (M&S) team for winter

maintenance. Coleambally Irrigation is also taking this opportunity for maintenance work on

Coleambally Main Canal offtake. The Gogeldrie Weir is expected back in service by this week,

when the gates would be reinstated and the pool would be raised a steady rate, typically less

than 300mm/day.

Hay Weir is being handed over to M&S team for winter maintenance. The gates are likely to be

lifted clear of water in the next couple of days.

Maude Weir is also being lowered gradually to facilitate planned maintenance work that is likely

to start in the next two weeks.


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Lachlan Valley

Storage Status

Carcoar dam is at 90% and releases have been reduced to riparian flow of 2 ML/d.

Wyangala Dam is at 88% of capacity and releases have averaged about 180 ML/d.


The tributaries D/S of Carcoar Dam are still able to meet the minimum flow at Helensholme,

therefore the release from Carcoar Dam will be maintained at the minimum of 2 ML/d.

The releases from Wyangala Dam are being scheduled from Power Station B, at minimum

capacity of 350 ML/D, during the business hours and reverting back to the valves at other times

at 90 ML/D with the aim of achieving an average release of 180 ML/d. The average flow at 180

ML/d is to assist Cowra Shire Council in extracting water for the water treatment facility.

The Lower Lachlan releases at Brewster have been averaging 550 ML/d to deliver Stock and

Domestic replenishment flows into Merrowie Ck, Willandra Ck and Muggabah Ck as well as

irrigation orders for about 8000 ML from HS licences being pumped into storages. The irrigation

orders for pumping from HS licences have ceased on 30 June 2017.


Supplementary access on the Belubula River recommenced on 21th May 2017 and continues.

Dam Spill Likelihood: Based on historical inflow conditions there is a 55% chance of Wyangala

Dam spilling by end of August 2017. However, BoM is forecasting a lower than average

probability of median rainfall in the catchment this winter.

The ongoing assessment of airspace requirements at Wyangala has not yet indicated the need to

make pre-releases. A teleconference with the flood panel to discuss the available airspace,

prognosis on inflows, likely irrigation demand, and potential dam operation for maintaining

airspace as required by the Lachlan works approval was carried out on the 6th June, 2017. The

consensus was that under current seasonal conditions irrigation demand may start late August to

early September, but be prepared to review this if there is general rainfall.

The translucent flow period is from mid-May to mid-November at the dam. The inflows to

Wyangala Dam from January to end of June totalled 46 GL. Another 204 GL of dam inflows are

required in order to trigger any delivery of translucent environmental water. As there is only 146

GL of airspace left in Wyangala Dam, it is highly likely that all three storages will fill and spill

before commencement of any translucent environmental water delivery.

Current demand in lower Lachlan River is being met from flows arising from the tributaries

downstream of Wyangala as well as releases from Lake Cargelligo storage. It is planned to

lower Lake Cargelligo storage from the current 120 % to maintain about 100%.


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DPI-Fisheries have given the permission to close the Island Ck Weir, including the Fish Ladder

from 1st May to 1

st August 2017. However, since the flow D/S of Jemalong Weir is still greater

than 350 ML/d, the fish ladder remains open until flows drop below this level.

As of 26th June 2017, the Lake Brewster inflow wetland level and the southern cell are at

139.20m (FSL level is 139.40m). An earthen bank has been built on top of the western spillway

in order to protect the pelican colony in the Northern cells from any rises in water levels and Dam

Safety has been informed of the possibility of surcharging the southern cell.

OEH has confirmed that there is no new evidence of young chicks and informed WaterNSW that

the pelican colony is potentially no longer sensitive to the changes in the lake level. Therefore,

water has been diverted from the inflow wetlands into the northern cells and also releasing more

from the outflow wetlands as part of the replenishment flows. The water diversion from the inflow

wetlands helps to open up the access road along the eastern spillway to recommence the repair

work on the inflow wetland embankments.

Latest samples from Lake Brewster show no cyanobacteria except the outlet channel. The outlet

channel is dominated by benign cyanobacteria. All sites are currently at green alert levels.


Jemalong Weir pool will not be drained as planned maintenance works are rescheduled to next year.

Account spill and reset of general security allocations

If WaterNSW were to commence dam releases to maintain airspace in Wyangala Dam, it will trigger an account spill and reset of general security allocation accounts, high security spillable sub-accounts and the conveyance licence account as per section 56 of the Lachlan WSP. DPI Water has announced that if there is an account spill and reset there will be no further reset in the following 6 months.


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Macquarie Valley

Storage Status

Burrendong Dam is currently at 87% and Windamere Dam is at 49%.


Currently releases from Burrendong are on the usual seasonal minimum of about 80ML/d.

Releases from Windamere are approximately 12ML/d.


No significant change is expected in the dam releases for this week.

Amber alert has now been lifted At Windamere Dam based on the 14th June test results. No

cyanobacteria were detected downstream.

Currently one trash rack is in place at Windamere dam and the height of the rack is 8-11m below

the surface. The position of the trash rack remained unchanged.

Dam Spill Likelihood: Based on historical inflow conditions there is a 45% chance of Burrendong

Dam reaching 100% by end of August 2017. However, BoM is forecasting a lower than average

probability of median rainfall in the catchment this winter. Burrendong Dam currently has

airspace of 147 GL to 100% and another 490 GL of airspace in the FMZ. It is highly likely that

demand for environmental watering and irrigation from August would increase the airspace

further.

DPI Water on 1 July 2017 announced AWD of 36% for general security licences in Macquarie

Cudgegong Rivers. This AWD is on top of estimated carryover allocations into 2017-18

equivalent to 73% in Macquarie and 137% in Cudgegong.

Minimal winter water usage is expected this year, with water being carried over for higher value

summer cropping.


The Burrendong cold water pollution curtain is not expected to be returned to operation until

spring 2017.

The main penstock at Burrendong Dam has been dewatered for annual maintenance. The outage

is expected to last until 31st July 2017 and the maximum release during this time would be

~220ML/d. Forecast demand (irrigation and environment) is likely to be well below 220ML/d,

consequently no customer impacts are expected due to the outage.

If there is a dam spill scenario after 1 July customers are likely to order their carryover. DPI Water

has approved rule changes relating to accounting of carryover spill in the WSP to minimise the

impact of planned works on the individual’s total available water.


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A customer notice has been issued notifying customers of the modification of the accounting

rule.

Namoi Valley

Storage Status

Keepit Dam is at 65%, Split Rock Dam is at 30% and Chaffey Dam is at 95% of active capacity.


Minimal releases are expected over the winter within the Upper and Lower Namoi Valleys

End of System releases to meet regulatory requirements continued from Gunidgera Weir, these

will continue until mid-August.

Licenced environmental releases of 1,250ML have been completed in the Peel Valley, while the

Environmental Contingency Allowance of approximately 4,960ML has been delivered and

ceased with recent rainfall.

Surplus flows in the Namoi continues to be captured and fill Mollee Weir.

Some limited take of general security in conjunction with End of System flows and replenishment

flow in the Lower Namoi is occurring.

Higher volume general security releases are not expected to commence from Keepit Dam until

September 2017 to meet summer cropping demand.


Generally catchment conditions are positive

Dam Spill Likelihood: Based on historical inflow conditions there is a 20% chance of Keepit

Dam spilling by October. However, BoM is forecasting a lower than average probability of



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Dam Spill Likelihood: Based on historical inflow conditions there is less than a 5% chance of

Split Rock Dam spilling by October.

Dam Spill Likelihood: Based on historical inflow conditions there is a 50% chance of Chaffey

Dam remaining full and spilling sometime before September. However, BoM is forecasting a

lower than average probability of median rainfall in the catchment this winter.

Carryover into 2017/18 within the Lower Namoi will be approximately 81%

Starting allocations in the Peel and Upper Namoi Valleys for the 2017/18 were 100% for GS.

A Bulk Water Transfer is planned to be undertaken from Split Rock to Keepit Dam in January

2018 if conditions remain dry. Customer and community consultation and meetings are being

planned to commence in July 2017.


Annual maintenance of weirs is complete; some minor work will be undertaken on manual

structures.


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Gwydir Valley

Storage Status

Copeton Dam is at 53%


No further significant releases are anticipated to be required prior to September 2017



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Dam Spill Likelihood: Based on historical inflow conditions there is less than a 5% chance of

Copeton Dam spilling by September. However, BoM is forecasting a lower than average

probability of median rainfall in the catchment this winter.

General security carryover into the 2017/18 water year will be approximately 61%.

A small supplementary event of approximately 1 700ML has been announced on Monday 3 July

2017.


Annual weir maintenance will be conducted over the winter months.

The Copeton Dam main penstock is currently dewatered to undertake maintenance work until

the end of August, releases of up to 500ML/day are still possible and no supply interruptions are

foreseen at this time.

Border Rivers

Storage Status

Pindari Dam is at 100% and continues to spill.


No releases are anticipated to be required until November 2017 due to the amount of water on-

farm.


Hydro station utilisation continues to be maximised while passing inflows at Pindari Dam.

On-farm storages are quite full with high levels of supplementary access and overland flow

throughout April 2017.

Catchment conditions remain wet with good downstream tributary inflows.


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100% of general security A has been set aside for the 2017/18 water year.

A small 8% AWD for general security B accounts occurred at the start of the water year, with

carryover of approximately 90%.

A small supplementary event of approximately 4 400ML has been announced on Monday 3 July

2017.


No flow and an empty storage are required at Boggabilla Weir to allow anode replacement, this

will be postponed due to continuing moderate flows, until flows reduce.


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Hunter Valley

Storage Status

Glenbawn Dam is at 88%, Glennies Creek Dam is at 83%, and Lostock Dam is 100% (spilling) of

active capacity.


Releases at Glenbawn Dam have been cut to zero from 3/7/17.

Glennies Creek Dam will have minimum releases.

Lostock Dam is currently spilling around 150ML/day.


Dam Spill Likelihood: Based on historical inflow conditions there is a 10% chance of Hunter

Dams spilling by December. However, BoM is forecasting a lower than average probability of


Expecting irrigation to decrease so little demand from this sector.


Nil


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0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

1/07/2011…

1/12/2011…

1/05/2012…

1/10/2012…

1/03/2013…

1/08/2013…

1/01/2014…

1/06/2014…

1/11/2014…

1/04/2015…

1/09/2015…

1/02/2016…

1/07/2016…

1/12/2016…

1/05/2017…

1/10/2017…

1/03/2018…

1/08/2018…

1/01/2019…

1/06/2019…

Sto

rage

% c

apac

ity

Hunter Dams - Forecast Storage Levels Minimum annual percentile inflows from 1 July 2017

Actual

80th%

50th%

20th%

Drought

90%

0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

1/07/2011…

1/12/2011…

1/05/2012…

1/10/2012…

1/03/2013…

1/08/2013…

1/01/2014…

1/06/2014…

1/11/2014…

1/04/2015…

1/09/2015…

1/02/2016…

1/07/2016…

1/12/2016…

1/05/2017…

1/10/2017…

1/03/2018…

1/08/2018…

1/01/2019…

1/06/2019…

Sto

rage

% c

apac

ity

Lostock Dam - Forecast Storage Level Minimum annual percentile inflows from 1 July 2017

Actual

80th%

50th%

20th%

Drought

90%


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Bega River

Storage Status

Brogo Dam at 100% and spilling


Will continue to pass inflows currently 49ML/day


Reduced demand, dam spills should meet demand.

Toonumbar Dam

Storage Status

Toonumbar Dam 101.5% and is currently spilling.


Will continue to pass inflows currently around 310 ML/day.


Reduced demand, expect spills to meet any demands

0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

140.00%

1/07/2011…

1/12/2011…

1/05/2012…

1/10/2012…

1/03/2013…

1/08/2013…

1/01/2014…

1/06/2014…

1/11/2014…

1/04/2015…

1/09/2015…

1/02/2016…

1/07/2016…

1/12/2016…

1/05/2017…

1/10/2017…

1/03/2018…

1/08/2018…

1/01/2019…

1/06/2019…

Sto

rage

% c

apac

ity

Brogo Dam - Forecast Storage Levels Minimum annual percentile inflows from 1 July 2017

Actual

80th%

50th%

20th%

Drought

90%


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0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

1/07/2011…

1/12/2011…

1/05/2012…

1/10/2012…

1/03/2013…

1/08/2013…

1/01/2014…

1/06/2014…

1/11/2014…

1/04/2015…

1/09/2015…

1/02/2016…

1/07/2016…

1/12/2016…

1/05/2017…

1/10/2017…

1/03/2018…

1/08/2018…

1/01/2019…

1/06/2019…

Sto

rage

% c

apac

ity

Toonumbar Dam- Forecast Storage Level Minimum annual percentile inflows from 1 July 2017

Actual

80th%

50th%

20th%

Drought

90%


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WATER NSW - DAM LEVELS The following table shows the current status of water supplies at 3 July 2017

1 Gigalitre (GL) = 1,000 Megalitres (ML) 1 ML = 1,000,000 litres

Rural Water Supply Weekly updates:

Urban Water Supply Updates: http://www.waternsw.com.au/supply/dam-levels/greater-sydneys-dam-levels

River Valley

Capacity

Current Status

Weekly change

(GL)

Comments

Likelihood

Allocations for 2017/18

Storage Dam, Nearest Town

(GL)

% of

active capacity

Active (GL)

Supply Issues

of fill and spill

High

Security

General Security

Carry-over @ 1/7/17

Border Rivers 100% 8% 87%

Glenlyon Dam, Stanthorpe Qld 254 75% 190 0 U/S Winter Supplementary available

Pindari Dam, Inverell 312 100% 313 0 Spilling, Small supplementary event DS 100%

Gwydir Valley

Copeton Dam, Inverell 1 343 51% 690 53

Minimum releases, small supplementary event

<5% 100% 0% 61%

Namoi Valley

Keepit Dam, Gunnedah 419 65% 273 4 End of System Flows and Env deliveries 20% 100% 0% 81%

Split Rock Dam, Manilla 394 30% 119 1 <5% 100% 100% N/A

Chaffey Dam, Tamworth 100 95% 94 0 50% 100% 100% N/A

Macquarie Valley

Burrendong Dam, Wellington 1 154 87% 1 008 1 Environmental deliveries ended 45% 100% 36% 73%

Windamere Dam, Mudgee 367 49% 181 0 Very low 100% 36% 137%

Oberon Dam, Oberon 45 88% 40 0 100%

Lachlan Valley

Wyangala Dam, Cowra 1 219 88% 1 072 0 Delivering S&D replenishment flows 55% 100% 0% 109%

Carcoar Dam, Carcoar 36 90% 32 0 100% 0% 95%

Murrumbidgee Valley 95% 17% 30%

Burrinjuck Dam, Yass 1 023 62% 638 1 Translucent releases 35%

Blowering Dam, Tumut 1 607 80% 1 285 61 Minimum releases 35%

Murray Valley Environmental deliveries 97% 11% 42%

Dartmouth, Mitta Mitta (Vic) 3 817 77% 2 925 2

Hume Dam, Albury 3 036 70% 2 118 29 50%

Lower Darling 100% 100% 77%

Menindee Lakes, Broken Hill 1 582 40% 631 -1 Releases for Env & Anabranch N/A

Hunter Valley 100% 100% 25%

Glenbawn Dam, Scone 750 88% 656 0 10%

Glennies Ck Dam, Singleton 282 83% 235 0 10%

Lostock Dam, Gresford 20 100% 20 0 Spilling 100% 100% 100% N/A

Coastal Area

Toonumbar Dam, Kyogle 11 102% 11 0 Spilling 100% 100% 100% N/A

Brogo Dam, Bega 9 100% 9 0 Spilling 100% 100% 45% N/A

TOTALS 17 780 70.5% 12 540 150

: NSW has water resources in Dartmouth, Hume and Glenlyon Dams. TWS = Town Water Supplies

water nsw water availability report · water nsw – water availability report ... bom’s 4 and 8...

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