Do I Need a Water Licence for a Farm Dam in Queensland? | Big Ditch

“Do I need a water licence for a farm dam in Queensland?” is one of the first questions I want answered before a machine arrives on site. The earthworks may be straightforward, but the right to take, divert or interfere with water is a separate issue. A dam can be physically sound and still be the wrong project if its water source has not been checked.

The answer is not simply “yes” or “no”. It depends on whether the storage catches rainfall and overland flow, sits in or near a watercourse, is filled from a bore or creek, or is used for stock, domestic needs or irrigation. Local water-plan rules matter, as do development, environmental and dam-safety requirements.

I have designed and repaired enough rural storages to know that the cheapest time to discover a restriction is before excavation. In this guide I will show you what to check, which questions to take to the Queensland authorities and how to keep the licence question separate from the engineering question.

What does a water licence actually cover?

A water licence is about the legal authority to take water, interfere with water or do both where those actions are linked. For a farm dam, that can include impounding water behind an embankment, diverting a watercourse, taking water from a creek or pumping groundwater to fill a storage. The licence is not a certificate that the dam wall has been designed correctly.

The source is the starting point. Rain falling directly into a basin is different from water captured from a defined watercourse. Overland flow can also be regulated differently between catchments. A bore that fills a dam raises another set of questions about groundwater management, pump capacity and the conditions attached to the take.

One megalitre is 1,000,000 litres, so even a modest-looking storage can represent a substantial volume of water. A 2 ML farm dam holds approximately 2,000,000 litres at full supply level, before allowing for evaporation, seepage and dead storage.

I recommend reading the Queensland guidance on when a water licence is needed and then confirming the position for the actual lot and plan. A general web answer cannot replace a property-specific check.

When might a Queensland farm dam need a licence?

You should assume a licence or other authorisation may be needed when the project takes water from a watercourse, lake, spring, groundwater system or regulated overland flow. It may also be needed when the dam interferes with the flow of a watercourse, including by storing water behind a wall or placing works in the bed or banks.

Stock and domestic use is not a universal exemption. The result can depend on whether the land adjoins a watercourse, which water plan applies and how the water is taken. Irrigation, commercial use and filling a dam from a creek generally deserve an early conversation with the relevant Queensland office.

A 100 mm rainfall event puts 100 litres on every square metre of catchment before losses. On a 10 hectare catchment, that is a theoretical 10 ML of rainfall, although infiltration, vegetation, soil moisture and runoff routing can reduce the volume that reaches the dam.

That simple calculation is useful for planning, but it does not establish a right to harvest the water. I have seen owners calculate an attractive yield from a catchment and overlook the fact that the proposed inlet crosses a watercourse or that the catchment sits inside a managed area.

How do overland flow, creeks and bores change the answer?

Direct rainfall and ordinary runoff into a self-contained depression are usually the simplest starting point, but “overland flow” is not a blanket permission. Queensland rules can identify areas where taking or interfering with overland flow needs authorisation. A contour bank, diversion drain or raised wall that changes where water travels may also be treated differently from a small basin that simply receives local rain.

A creek, gully or drainage line brings a higher level of scrutiny. A dam that blocks or diverts a watercourse can affect neighbours, fish passage, downstream flows and flood behaviour. You may need a water licence, a riverine protection permit, development approval or several of these. The exact combination follows the water plan and the proposed works, not the name you give the dam.

A bore-filled dam has its own logic. A licence or permit may control the volume, rate and timing of groundwater extraction. The pump might deliver 8 litres per second, but that does not mean the property is authorised to run it continuously. Work out the intended annual take in megalitres and compare it with the entitlement and any metering conditions.

In 2021, on a 42-hectare grazing property near Toowoomba, Queensland, Lindsey Hughson stopped a proposed dam layout at the first walk-through because the owner’s “runoff” inlet was actually tied to a defined drainage line. Lindsey’s advice was practical: keep the dam design moving, but redraw the source and ask the water authority the right question before a dozer made the decision expensive.

What should I check before digging?

I use a short sequence that keeps the paperwork and the earthworks aligned. It prevents a common mistake: getting a contractor’s price first and discovering later that the proposed storage cannot be filled or operated as planned.

1. Mark the dam, inlet, outlet, diversion and pump locations on a current property plan.
2. Identify every proposed water source: direct rainfall, overland flow, creek, spring, lake, bore or water cart.
3. Check the Queensland water plan, catchment rules and any existing licence, allocation or water entitlement attached to the land.
4. Ask the local business centre whether taking or interfering with water needs a licence, permit or development approval.
5. Check local council planning controls, vegetation rules, road access and any waterway-barrier requirements.
6. Have the dam geometry, soil profile, spillway and safe access reviewed before finalising the excavation volume.

Keep written answers with the project file. Record the property description, the proposed storage size in ML, the source of inflow and the intended use. If the advice is verbal, follow up by email so there is a clear record of what was asked and what was answered.

A 600 mm freeboard is not a universal legal requirement, but it illustrates why design and approval should be considered together. Freeboard is the vertical distance between the normal water level and the crest; its amount depends on catchment, wave action, embankment geometry, spillway performance and risk.

Which other approvals and safety checks sit beside a licence?

A water licence answers a water-authorisation question. It may not answer whether the earthworks are permissible under planning rules, whether filling a watercourse needs a riverine protection permit or whether a dam is a referable structure. Queensland’s guidance on building or buying a dam is a useful official starting point.

Queensland guidance identifies dams whose failure could put two or more people at risk as referable dams. For larger structures, the published thresholds include a dam more than 10 m high with storage above 1,500 ML, or more than 10 m high with storage above 750 ML where the catchment area exceeds three times the maximum surface area at full supply level.

Those thresholds are not a target to design around, and they are not a substitute for a failure-impact assessment where one is required. A smaller dam can still create a serious hazard if a house, road, neighbouring property or public area sits below it. Put people and downstream consequences on the drawing before choosing the wall height.

Do not forget the physical details. A 3:1 upstream batter means 3 m of horizontal run for each 1 m of vertical rise, and a 2.5:1 batter means 2.5 m for each 1 m of rise. The chosen slope, keyway, compaction and spillway all affect stability, storage and the amount of land disturbed.

Our guide to dam keyways explains why the wall must be tied into competent foundation material. For ongoing risk control, use the farm dam maintenance checklist to inspect the spillway, wet spots, cracking, trees and stock damage after construction.

What information should I prepare for the water-authority conversation?

Make the first conversation easy to answer. Give the authority the lot and plan, property address, catchment, nearest watercourse, proposed dam footprint, wall height, full-supply area, estimated capacity and the way water will enter. Include whether the water is for stock, domestic use, irrigation, firefighting or a mix.

If the dam will be filled by a pump, include the pump’s proposed rate and the expected operating hours. If it will catch runoff, include the catchment boundary and the diversion path. A rough survey is better than a verbal description, but a final design should use levels that let the spillway and freeboard be checked properly.

At Big Ditch, I separate three questions during a site assessment: can the ground hold the wall, can the spillway pass the water safely and can the proposed water source legally feed the storage? A “yes” to the first question does not answer the other two.

If you want a second set of eyes before you lodge an application, send the site details through our farm dam planning contact page. We can help you define the storage, inspect the soil and identify the questions that need to go to council or the Queensland water authority. We do not replace the regulator’s decision, but we can help you arrive with a clearer project.

If your dam is a small, self-contained rainfall storage with no defined watercourse, no diversion and no managed bore filling it, the licence question may be simpler. It is still worth confirming the catchment rules before excavation. If the project captures water from a creek, spring, lake, bore or regulated overland-flow area, treat authorisation as a project requirement, not an afterthought.

Start with the water source, then check the water plan and existing entitlements. Next, check planning, environmental and safety controls. Only then should you lock in the dam footprint, wall height, spillway and construction method. That order saves more money than trying to compress the whole decision into a machine hire window.

Remember that conditions can change between properties only a few kilometres apart. A farm dam water licence Queensland landowners need is determined by the site and the proposed take, not by what a neighbour did years ago. Get the property-specific answer in writing and keep it with the design documents.

Frequently Asked Questions

Do I need a licence for a small dam used only for stock?

Not always. The answer depends on the water source, whether the property adjoins a watercourse and the rules in the relevant Queensland water plan. Confirm the position for the actual lot before you build, rather than relying on the dam’s size or its intended use.

Does catching rainwater in a dam need a water licence?

A basin that receives direct rainfall can be simpler than a dam that captures a creek or regulated overland flow. However, an inlet, diversion drain or wall that changes natural flow can introduce additional requirements. Ask the Queensland water authority to assess the proposed source and works together.

Can Big Ditch tell me whether my licence will be approved?

No contractor can guarantee a regulator’s decision. We can inspect the site, estimate storage, map the inflows and help you prepare a clear set of questions and drawings. The relevant Queensland authority makes the authorisation decision and sets any conditions.

Need a clear licence pathway for your dam? Book a site inspection with Big Ditch before your earthworks quote is locked in.