Frequently asked questions

Within NSW, the sharing of available water is undertaken in accordance with the priorities for water sharing set out in the Water Management Act 2000 and the respective statutory water sharing plans for water sources. For the NSW Murray, Murrumbidgee and Lower Darling rivers, the department must also consider interstate water sharing agreements and/or Snowy Hydro Scheme operations.

While the process for determining water availability and announcing available water determinations (typically referred to as allocations) is relatively straight forward, catchment conditions, climate variability, seasonal circumstances and a number of operational considerations can influence the allocation outcome. Nevertheless, the basic approach is outlined below.

Immediately prior to the commencement of the new water year on 1 July, the department calculates the minimum assured volume of water that will be available for allocation within each water source during the coming year.

This includes:

• how much water is available in the storages; plus
• a minimum natural inflow into storages (based on the historical record at the time of the first water sharing plan – 2004 for many regulated river valleys); minus
• the volume required to run the river, including end of system flows, transmission losses and evaporation losses; minus
• other water sharing plan requirements, including storage reserves and credits to environmental water allowances; minus
• existing commitments, such as water to meet on-going high priority commitments including conveyance accounts and general security carryover.

When allocating water, the department is required to first ensure, as far as practicable, that two years of critical requirements can be met, before allocating to lower priority (general security) licence categories.

Water allocation guides have been prepared for major regulated river valleys in NSW.

Opening water allocations for the 2022/23 water year for NSW licenced water users reflects a turnaround from drought conditions experienced in 2018 and 2019, to an abundance of resource. Rainfall across much of the State has been well above average, providing significant flows into the river systems.

All critical needs, including town supplies, are secure for the 2022/23 water year and all regulated river valleys have received their usual full opening allocation for high security licences.

Most higher priority licence categories cannot carryover water; they forfeit unused account balance each water year. Therefore, opening water allocations are mostly about ensuring annual allocations are provided for all higher priority entitlements including towns, domestic, stock and high security licence categories.

Commencing general security water availability is healthy across all regulated valleys, reflecting full or near full storages in most of the major dams.

Supplementary access entitlements for all inland valleys have received their full (100%) allocation for the 2022/23 water year, with the exception of the Gwydir and Border Rivers. However, use of supplementary access account water can only be made during declared periods of supplementary flow.

It should be noted that water sharing plans required compliance with Long Term Average Annual Extraction Limits (LTAAEL) and that allocation to supplementary access licences can be reduced if LTAAEL is exceeded.

For start of the 2022/23 water year, this will apply to the Gwydir and Border Rivers, where a reduction is required to manage growth in use of floodplain harvesting. These two water sources were similarly reduced last year with supplementary access allocations of 75% and 50% of entitlement in the Border Rivers and Gwydir respectively on 1 July 2021.

Given that last year was the first time growth in use had been implemented in surface water sources, the reductions in the Gwydir were limited to 50% to allow water users time to adjust. For this year, the reductions in the Gwydir reflect the full volume of reduction required to manage growth in use.

The new water sharing plans for these areas are likely to commence in 2022/23. The changes to the plans will manage the growth in use, and supplementary allocations can be increased, when the new plans commence.

All groundwater users have received a full allocation, apart from those (typically alluvial aquifers) linked to a surface water allocation.

Unregulated river access licences have all received their usual full allocations at the start of the water year. However, take is limited to specific river levels, including river levels below which pumping must cease to protect low river flows. Water access is only available when river flow conditions stipulated on the licences are met. Therefore, under dry (low flow) conditions, unregulated river water users normally cannot take water regardless of their account balance.

As the year progresses, regular assessments of surface water availability are undertaken. Improvements from inflows to storages following rainfall, as well as less than forecast transmission losses, are continually monitored so that any possible increases to water availability can be promptly allocated. Allocations can continue to accrue if resources improve, up to maximum account limits set out in respective water sharing plans.

Forecasts indicate likely wetter than average conditions for the coming months. Where possible, new water resources will be captured and allocations incremented in accordance with water sharing plan rules.

Total storage levels for WaterNSW operated dams as at 17 June 2022 were about 17,300 gigalitres, which is around 97% of total active storage capacity.

The storage volume for major state-operated dams this time last year was approximately 62%.

This shows a major improvement of 35% in overall storage levels across the state compared with the same time last year, noting there are some variations from valley to valley, as reflected in this year’s opening water allocations.

Water sources and entitlements that have received their maximum permissible allocation for the year, in accordance with the relevant water sharing plan, will not receive any further allocation until the next water year (2023/24).

For water sources and entitlements which are not at their maximum permissible limit, typically general security entitlements in regulated valleys, resource assessments are generally carried out monthly and allocations made if further resource is available, in accordance with the rules of the relevant water sharing plan. New resource typically eventuates from additional rainfall and runoff across the year.

For information on the next regulated valley allocation update, please refer to the regulated water allocation statements on the department’s website.