Managing groundwater extraction to extraction limits

What is this about?

The amount of groundwater that can be extracted from a groundwater source is limited.

Water sharing plans set long-term average annual extraction limits and Basin Plan sustainable diversion limits.

While the total amount extracted by all water users varies each year, on average it cannot exceed the extraction limits.

Before July each water year, the department assesses the level of extraction in each groundwater source. If average extraction by all water users exceeds the limits set out in the water sharing plan, the department may need to reduce access in the following year/s to return average extraction to the limit. Under the water sharing plans, this can be done by:

• reducing the amount of water going into accounts (known as an available water determination)
• reducing the amount of water that can be taken or traded from accounts (known as a maximum water account debit), or
• a combination of these methods.

The most appropriate approach taken may differ from area to area.

Between November 2020 and March 2021, we sought comment on the method or combination of methods that best suits areas that are most likely to exceed groundwater extraction limits in 2020-21. These areas (groundwater sources) were the:

• Great Artesian Basin Eastern Recharge
• Lower Murrumbidgee Deep
• Upper Macquarie
• Lower Lachlan
• Upper Namoi Zone 3
• Upper Namoi Zone 5
• Upper Murray

We will seek feedback from other areas in the future if they are likely to exceed their extraction limits.

What we heard at our consultation sessions

Water sharing plans allow the NSW Government to manage extraction to extraction limits by reducing the available water determination or the maximum water account debit or a combination if extractions by all water users exceeds limits. Other options are not available under the water sharing plans.

The focus of this consultation was on how we apply the methods currently available under water sharing plans to manage groundwater extractions to extraction limits. We sought stakeholder views on:

• what method or combination of methods permitted under the current water sharing plans we should use
• whether we should continue to apply the current assumptions for predicting future use or if we should use different assumptions in calculating an available water determination or maximum water account debit
• the timeframe for returning extraction to extraction limits if limits were exceeded (a maximum of 3 years was suggested)
• what implications there are for introducing a new procedure to manage extraction to the limits in the next water year (1 July 2021) and if a transition period is supported before a new procedure is introduced.

More information

We will seek feedback from other areas in the future if they are likely to exceed their extraction limits.

Presentations with more information on extraction limits, extraction patterns in each groundwater source and the options being considered if extraction limits are exceeded are available for each groundwater source listed below.