Current Water Availability

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Current Water Availability

New South Wales Department of Industry - Water, together with WaterNSW (for supplementary flows) are responsible for announcements regarding water availability within plan areas.

Annual starting allocations are determined on the 1 July each year and, depending on the entitlement type, additional available water determinations may be made depending on water resources available for sharing throughout the water year, as with General Security (generally in first week of the month) or at the beginning of an event for supplementary water.

Current allocations and their date of announcement are provided below and are presented as a chart this includes water available and usage to date.

For a complete record of water allocation statements, visit the Department of Industry website here.

2020-21 Water Year

At the start of the current water year (1 July 2020) there was 12,560ML of general security water allocation carried over for irrigation and 30,000ML for environmental water managers (NSW and CEWO held, and Environmental Contingency Allowance).

Full allocations were announced for critical water users including high security users and groundwater, were made available.  Groundwater users have limited carry over allocations with an estimated 15,900 megalitres remaining.

Whilst a full supply of essential water requirements are reserved for two-years and reserves for delivery of water have been made, all water users will need to work collaboratively to ensure losses are minimised to make the most of remaining allocations.  GVIA and WaterNSW will engage with water users and monitor any natural inflows to maximise opportunities to efficiently run the river.   Water NSW provided the following operations update in July 2020.

The below chart provides a graphic of the available water in accounts for each of the water entitlements and categories and outlines, with text the water use so far this season.  This information is provided via resource assessment updates for the regulated system and monitoring of groundwater usage.  This information is available in the following tables.




Regulated System - High Security and General Security

Current water availability in Copeton Dam is highlighted on our sidebar (on the right) but is also broken down by entitlement type below.   High security as well as town water supplies and stock and domestic users, as well as the losses to deliver this water are included in the 'essential supplies' section.



A breakdown of General security allocations for the current water year are detailed below.

A detailed breakdown of general security monthly allocations, usage and remaining general security balances are provided in the following attachment.

Regulated system - Supplementary access.

Partial supplementary access was provided in during flows in February and March 2020, resulting in between 5-20% access for some water users. These flows provide for minimum requirements to meet basic and critical water needs and therefore, in the event of further inflows normal sharing arrangement would be considered.  

Essentially these flows were across seven discrete events from January 2020 through to April 2020.  The GVIA includes the January flush event that provided for town water supplies for Weemelah and also, separates the localised flooding in early February as a separate event to the flows that occurred from upstream of Pallamallawa at a similar time.  For this reason, we consider there to be seven events for 2019-20 rather than WaterNSW five. These flows were the first since October 2017.

The current supplementary roster which is used to guide where supplementary events may be directed to, given the opportunity arises and the river operators have the ability to direct the flow.

Unregulated system

As with supplementary access, most unregulated creeks and streams received some flows in February and March 2020.  Full allocations are available if access conditions are achieved.

Any restrictions in place are available via Department of Industry website

2019-20 Water Year

Last water year, there was no general security water used for irrigation as deliveries were not possible. There was 18,000ML used from environmental accounts to provide small river flows.

High security users used nearly their highest historical volume of 10,508 ML with water delivered in block releases, often with environmental water throughout the season.

Towards the end of the water year, two small allocations were made to General Security and environmental water users, providing a total of  2.17% allocation.  

In February through to April, there were unregulated flows that would have meet the normal water sharing plan conditions for supplementary access.   Partial access was provided to these flows given the extreme no-flow conditions across the northern basis.  Total access of 20,000 ML was provided (although environmental water managers called on 3,448ML of that) an further 17,800ML would have been available under normal water sharing rules if restrictions were not in place.  Analysis by GVIA indicates that around 10,000ML could have been shared without compromising downstream outcomes if all water sharing plan rules and channel constraints were applied.  This water was foregone by our community.

As of 30 June 2020 (the end of the water year) there was 12,560ML of general security water allocation carried over for irrigation and 30,000ML for environmental water managers (NSW and CEWO held, and Environmental Contingency Allowance).  

A summary of water usage by category is provided as calculated on 30 June 2020.

Entitlement Type Irrigation (ML) Environmental (ML) Allocation % Date Irrigation usage (ML) Environment usage (ML)
High Security 14,069 690 100% 31-May-2020 5,441 5,067
General Security* 12,560 11,900 2.17% 31-May-2020 NA 9,673
ECA NA 18,960 2.17% 31-May-2020 NA 5,200
Supplementary ** 10% March 2020 15,197 2,820
Groundwater 15,913 5,700 100% 30-Jun-2020 25,358 5,700


* Environmental Water Holders transfer HS into GS for usage
** Environmental Water Usage reconciled only until 31 May 2019.


Some entitlements (general security and groundwater) provide carryover mechanisms for unused allocations, these can be used in the following water year in addition to any new allocations.

Key summary:

  • Valley inflows were near the lowest on record until February - April, when the region received good rainfall as well as flash flooding.  Total inflows for the valley were approximately 120 GL for the year.
  • Irrigators and environmental water holders will carry over remaining water, other than high security into the next year. 
  • Temporary restrictions were in place in the region from December 2019 through to late February 2020.  During this time, localised flooding occurred with overland flow, unregulated access and supplementary access were trigger but mostly restricted.  Partial access was provided with 18,000ML accessed from the various sources, a further 17,800ML would have been available under normal water sharing rules.  Analysis by GVIA indicates that around 10,000ML could have been shared without compromising downstream outcomes if all water sharing plan rules and channel constraints were applied.  This water was foregone by our community. 
  • Reserves are such that all essential supplies are secured for two-years and the required delivery loss water is available.
  • Groundwater usage totalled 25,358 megalitres.  Monitoring using the three-year rolling average as described in the Water Sharing Plan for the Lower Gwydir Groundwater Water Sources (2016) revealed that usage is below the Plan Limit.


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Securing a future for the Gwydir Valley through Irrigated Agriculture.