Overland flow

Overland flow is water that runs across the land after rainfall, either before it enters a watercourse, after it leaves a watercourse as floodwater, or after it rises to the surface naturally from underground.

It does not include:

water that has naturally infiltrated the soil in normal farming operations
irrigation tailwater if its recycling meets best practice requirements
water collected from roofs for rainwater tanks.

Most water in our rivers and underground reserves originates as overland flow water. Capturing and storing this water is referred to as overland flow development. This development can reduce the volume of water entering streams and rivers and therefore impact on water available for pasture, towns and farms.

How overland flow is managed

Rules in the Water Regulation 2016 and related documents regulate the building of new works that actively or passively take overland flow water.

You can take overland flow for any purpose unless there is a moratorium notice or a water plan that limits what can be taken.

A water plan may:

regulate existing works that take overland flow
state management rules aiming to protect the security of existing water entitlements and environmental water needs.

Where the construction of overland flow works is regulated, the development may be either assessable or accepted development under the Planning Act 2016.

If overland flow water is regulated in your area, you may need to apply for a water licence.

Contaminated agricultural runoff

Overland flow water that is contaminated with chemicals used in agriculture needs to be captured to prevent harm to streams and rivers.

Contaminated agricultural runoff is overland flow water that contains excess nutrients or farm chemicals that can harm the quality of water in streams and rivers.

The appropriate management of contaminated agricultural runoff is important to prevent harm to streams and rivers, however, capturing more than what is needed can impact on other water users and environmental needs.

If you have an obligation under the Environmental Protection Act 1994, you may take contaminated agricultural runoff to comply with this requirement.

Managing contaminated agricultural runoff in the Queensland Murray-Darling Basin

New works to capture contaminated agricultural runoff in the Queensland Murray-Darling Basin must operate under store and release arrangements.

This involves storing contaminated water, monitoring the water quality, then releasing the water to the environment when it no longer poses a contamination risk.

State Development Assessment Provision State Code 10 (PDF, 243KB) outlines the assessment criteria for works constructed to capture contaminated agricultural runoff water.

Check your water plan for guidance on taking overland flow or contaminated agricultural runoff, or contact your local business centre for advice.

Existing works for taking overland flow

Existing works for taking overland flow are those:

legally constructed under a moratorium
as defined under a water plan.

Notification of existing works

The relevant water plan for your area includes notification requirements for existing overland flow works.

Certifying works

If you are not sure about the capacity of existing works, you can have the works formally certified by an accredited engineer or surveyor.

Maintaining existing works

You can continue to maintain or repair existing works in an area where overland flow is regulated to ensure they continue to operate. You must not increase the capacity of the works to contain overland flow as a result of maintenance or repair.

Maintenance includes:

de-silting the storage (not deepening)
repairing embankments, bywash facilities, pipes and pumps.

You should contact your local business centre before carrying out any maintenance or repairs or to find out more about overland flow in specific water plan areas.

New works for taking overland flow

You may take overland flow water for any purpose unless there is a moratorium notice or water plan that limits or alters the water that may be taken.

Regulating new works

Building new works to take overland flow water is regulated under the Planning Act 2016. This applies to works identified as either assessable or accepted development in a water plan or the Water Regulation 2016.

Moratoriums

Moratoriums can be declared to suspend construction of new works for taking overland flow as part of the water planning process. This ensures that all existing uses are properly accounted for and that no further development takes place while a water plan is being developed. Moratoriums can continue until a water management protocol is in place.

Assessable development

Before constructing assessable overland flow works a person must hold a development permit. Assessable development requires approval from the State Assessment and Referral Agency.

Accepted development

Accepted development must comply with the relevant accepted development requirements. Under these requirements, you must notify the Department of Local Government, Water and Volunteers of any new works within 60 days of their completion. This enables the department to monitor changes in water use within the catchments, and the data will be used in future water planning.

Acceptable development includes works to take overland flow water:

for stock or domestic purposes
using limited capacity works (as limited in certain water plans)
for environmentally relevant purposes.

Contact us

For further information on overland flow, contact your local business centre.

Overland flow works that require certification

In some cases, a water plan, water management protocol or code may require a landowner to provide a certified report when applying to reconfigure existing overland flow works or a new water licence to take overland flow.

Certification should be carried out by (or under the supervision of) a registered professional engineer of Queensland (RPEQ) on behalf of the applicant.

RPEQs are required to exercise professional judgement in determining any matters, and the basis for decisions should be explained in the certification. The applicant is responsible for securing the services of a RPEQ and paying any associated fees.

Certification by an RPEQ results in 2 documents:

a registered certificate
associated supporting details contained in a report that have been 'certified' (verified and signed) by the RPEQ.

Certified documents

The certification documents included with the water licence application will be used by the Department of Local Government, Water and Volunteers to make decisions about the proposal. The certified documents must be signed by the RPEQ and the person who currently takes, or intends to take, the overland flow water.

A certified report must provide specification on overland flow structures including:

details of works
dimensions of works
capacity to take overland flow
any attached design or survey plans.

Certification does not have to include the entire property. The report can refer to the relevant section of the property when only a small portion of the development requires certification. It is important to show the hydrological connection between that particular development and any other developments on the property, either via a schematic diagram or a property plan.

Information to include

The following information could be included in the certification documents:

a completed storage data table. If unavailable, the top water level (RL), crest (RL), inlet pipe (RL) and outlet pipe (RL) may be excluded
a statement of the calculation method used in determining the capacity of works
a statement of the sources of water held in the storage (e.g. overland flow, river allocation, bore water)
a statement on the management of inflows and outflows from the storage
long-section of the crest and justification of selection of crest (RL) including year of construction, details on maintenance and history of filling to capacity
a storage capacity curve or table showing storage volume in megalitres versus water depth (AHD).

You may also need to provide an A3 schematic site or property plan:

showing the location of the storage on the farm
illustrating the flow path of overland flow in the vicinity of the storage (including tailwater return from fields)
clearly identifying any proposed changes to overland flow paths where necessary
locating and detailing any benchmarks
marking where the point of capture and control point will be (i.e. pump, channel)
marking the general inflow and outflow points for overland flow
for larger proposals, marking where the low points are (RL in metres)
0.5m contours and all data points used in generating the contours
crest length and width
inside toe length and width
multiple survey points along the inside crest, outside crest and inside batter toe at a maximum spacing of 10m
internal natural surface at all changes in grade
internal borrow pits at all changes in grade and alignment
significant features such as bywash location and level, inlet and outlet pipes, point of entry of uncontrolled overland flow
any other features that affect the determination of storage volume, including linkages with others storages.

Applications for a new water licence for overland flow water

Applications accompanying certification documents must be made on the relevant forms and include the required fee. Any applications are required to be submitted as part of the assessment process when lodging the certified report. If the authorisation is granted, the type and its specifications will vary depending on the level of certification and the department's requirements.

For more information, contact your local business centre.

Overland flow measurement

We are improving the way we measure overland flow take. We are trialling this in the Queensland Murray-Darling Basin (the QMDB) to support responsible and sustainable water management.

Overland flow water is an important source of irrigation. In parts of the QMDB many landholders capture and store this water on-farm for future use. Because most water in rivers, streams and groundwater systems begins as overland flow, knowing how much is taken is essential for long-term planning and fair access to water.

We manage overland flow through licensing and measurement. This ensures everyone uses the resource responsibly and a share remains available for communities, agriculture and the environment.

Licensing overland flow take

We use water plans to sustainably manage and allocate water resources, including overland flow.

We tailor water plans to balance the needs of water users (e.g. towns, agriculture and other industries) and the environment.

Through our water planning process, we assess the risks of overland flow take on water users and the environment. If risks are identified, we develop rules for water use, limits on how much water can be taken and ways to protect water availability and access.

We may implement these requirements through a licence that sets out clear rules and limits on how much overland flow water you can take.

Our focus for overland flow licencing is the QMDB.

Measurement requirements

Queensland’s non-urban water measurement policy (PDF, 2.1MB) outlines how we want to improve water measurement across the state, including the measurement of overland flow water.

The policy's implementation plan sets out the priorities for improving measurement and the timeframes for implementation.

Under the policy, the holder of an entitlement to take overland flow will be required to have a measurement plan in place for their property. The priority for measurement plan implementation is the QMDB.

A measurement plan will provide a consistent and transparent way to measure and record overland flow take. It will outline:

how you capture, store and use overland flow water on your property and
how you measure and calculate the volume of overland flow you take.

Overland flow measurement trial

Before requiring measurement plans through regulation, we are testing how they work on-farm. The trial will help to decide if measurement plans are practical, reliable and suitable across different operating conditions.

The trial will be run on up to 10 existing overland flow properties in the Lower Balonne water management area (PDF, 947KB) and the Border Rivers and Moonie water plan area (PDF, 794KB).

Trial stages

The trial has 2 stages.

Stage 1 – Measurement plan set-up

preparing properties for measurement and developing a measurement plan for each participating property

Stage 2 – Event measurement

using the plans during overland flow events and testing how measuring and calculating water take works under different flow conditions

The length of the trial will depend on the timing and number of overland flow events. We need multiple events to fully evaluate the approach.

Current status

The trial is underway in the Lower Balonne water management area (PDF, 947KB). We are working with participants and developing measurement plans for their properties.

We will use the results from the trial to refine our measurement plan approach and to develop the operational and administrative requirements needed to put measurement plans into practice.

The non-urban water measurement policy and overland flow measurement trial are part of the Queensland Government's commitment under the Murray-Darling Basin Compliance Compact (PDF, 1.47MB) to improve water measurement and compliance in the QMDB.

Also consider...

Read about water management in the Queensland Murray-Darling Basin.
Read more about water metering in Queensland.
Find out how overland flow is currently managed in Queensland.
View the Border Rivers and Moonie water plan and the Condamine and Balonne water plan.