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Floodplain harvesting and overland flows

Floodplain harvesting is when the water that flows across the floodplains during a flood is collected and used later.

Overland flow refers to water that runs across the land after rainfall, flooding, or after it rises to the surface naturally from underground. Capturing this water on a floodplain is referred to as overland flow development or floodplain harvesting.


Key facts

Floodplain harvesting has been regulated under the cap system since 1995, although it has never been fully measured and accounted for.

As floodplain harvesting is licensed and accounted for, it will be incorporated within the sustainable diversion limits established under the Basin Plan. This will see the sustainable diversion limit increase.
Any change to floodplain harvesting regulations will mean the water limits and water resource plans will need to be updated to incorporate these changes.
This does not mean more water is available for use, this water is in use already—it is just ensuring that it is robustly measured and can be monitored to ensure use does not grow over time.

Any changes will be independently assessed before they are incorporated into the Basin Plan.




Floodplain harvesting has been regulated under the cap system since 1995, and the proposed changes mean usage will typically now be restricted to the levels used in the year 2000. Doing so will make these limits consistent with the Basin Plan, existing arrangements for other water use, and represents a lower level of overall water use that was in place under the cap in 1995, which is considered sustainable.

Work is underway in New South Wales (NSW) and Queensland (Qld) to better understand how much water is harvested from floodplains now, and how much was being harvested prior to the Basin Plan.

At its heart, the Basin Plan sets the amount of water that can be taken from the Basin each year, while leaving enough for our rivers, lakes and wetlands and the plants and animals that depend on them.

It has been very difficult to accurately measure how much floodplain water has been used or ‘harvested’, meaning this water use is not accounted for in the rigorous way other water use is accounted for.

Licensing floodplain harvesting will bring this water use and local rainfall runoff into the regulated system, improving compliance and accounting of water use in NSW and Qld.

We welcome the proposed changes from NSW and Qld governments. Measurement and compliance of floodplain harvesting must be improved—so over time, we can ensure this use does not exceed the limits.

It is important that any change to licenses and new improved information about water usage is reflected across the whole water management system and in the day-to-day operation of the Basin Plan.

It is expected that as licensing, monitoring and compliance arrangements are improved, the total amount of water used through floodplain harvesting will be managed within the limits established under the Basin Plan.

Changes in New South Wales

The NSW Government has sought input from the community on licensing floodplain harvesting as part of the regulated system with all other water licenses. 

The NSW Government is proposing that water harvested from floodplains will be limited to the levels used in the year 2000. This is in line with the baseline diversion limits under the Basin Plan. If use has grown since this time, this will require current levels of harvesting to be reduced.

As floodplain harvesting is regulated and measured, sustainable diversion limits in NSW will change to properly include floodplain harvesting along with other forms of take.

Over the past few years, NSW has considered data from hydraulic models, gauged streamflow, remote sensing, satellite imagery, aerial photos, flood and licensing records, as well as survey and on-ground inspection data.

This work was part of the Australian Government funded ‘Healthy Floodplains Project’ in NSW to improve data and planning for floodplain harvesting.

More information

Changes in Queensland

Queensland is undertaking a different process to monitor and measure floodplain harvesting and overland flows. Queensland water plans manage the use of overland flow to levels of development in 2000, and a moratorium on floodplain harvesting development was put in place in September that year. Additional work is planned through the Queensland Rural Water Management Program to enable improved measurement and monitoring of the use of overland flow in these plan areas.

For all areas, licences are granted, as needed, to ensure there is no increase in the capture of overland flow water (such as when an irrigator applies for a trade, or for new works on their property).

In the Lower Balonne region, overland flows is measured using storage meters. A measurement project is underway to provide better information in other areas.

Queensland has recently committed to the full measurement and licensing of the Border Rivers floodplain by 2022.

Once overland flows are fully measured and licensed, water limits in Queensland will be revised to capture the best information.

New information on overland flow use will need to be included in updated estimates of baseline diversion limits, which are outlined in water resource plans. This means water resource plans will change over time, as the representation of overland flow water use improves.

More information

Next steps

The NSW Government and the MDBA commissioned an independent review of work being done in NSW. The review is looking at modelling NSW which is undertaking to improve estimates of current and historical floodplain harvesting and issue volumetric licences, including its relation to the Basin Plan. Read and comment on the draft findings from the Independent Panel.

Both the MDBA and the NSW Government will consider the findings from the independent review. The independent panel is also presenting their findings to Basin communities.

Once the recommendations of the review are addressed, the NSW Government is expected to commence the volumetric licensing process for floodplain harvesting, consistent with the NSW Floodplain Harvesting Policy.

The NSW Government is expected to submit changes to the water limits and water resource plans to the MDBA—to ensure this new information is reflected across the whole water management system.

It is expected that overland flows in the priority floodplains in Queensland will be licensed by 2022.

The Queensland Government continues working with floodplain harvesters to extend measuring and licensing.

Once these changes are complete, the Queensland Government will need to submit new information and changes to the MDBA and these will need to be incorporated in the water limits and water resource plans.