Dams – Private Property
What is a private dam?
- Gully dams; usually consist of an earth embankment constructed across a gully, valley, natural depression or fold in the land.
- Hillside dams; usually consist of a 3 sided or single crescent / curved embankment and, as the name suggests, situated on the side of a hill or slope.
- Excavated tank dams; can consist of an excavation below the natural surface level or may also include above-ground engineered earth embankments surrounding an excavation, allowing for increased water storage above and below the natural surface level. Excavated tank dams are usually used to store water that is diverted from rivers, creeks or groundwater bores and are common in flat areas where it is not possible to construct a gully or hillside dam.
- On-stream dams; are similar in design to gully dams and usually consist of an earth embankment situated on a waterway.
What licences do I need?
The licences that you may need for your private dam include:
- A Surface Water (take and use) Licence
- A Works Licence (to construct)
- A Private Dam Operating Licence
Anyone who wants to construct, alter, repair or decommission a dam on a waterway must obtain a Private Dam Construction Licence before starting any works.
You may also need a licence to build and operate a dam that is not on a waterway if you are proposing to build a large dam, or potentially hazardous dam.
This will depend on the size, location and potential hazard of the dam.
A large or potentially hazardous dam is a dam that:
- Has a wall that is 5 metres or more high above ground level at the downstream end of the dam and a capacity of 50 megalitres or more; or
- Has a wall that is 10 metres or more high above ground level at the downstream end of the dam and a capacity of 20 megalitres or more; or
- Has a wall that is 15 metres or more high above ground level at the downstream end of the dam, regardless of the capacity; or
- Is a dam belonging to a prescribed class of dams (at the moment, there are no prescribed class of dams)
It is your responsibility to ensure that you comply with the Water Act 1989. We advise that you contact us on 1300 139 510 to discuss licensing requirements before starting any works.
Please note that as well as a works licence, most local Shire Councils require a planning permit. You should contact your Shire Council to discuss.
If you have any enquiry about other works on waterways (eg bridges, culverts), contact your nearest Catchment Management Authority.
How do I obtain a works licence?
Do I need a dam operating licence
- Situated on a waterway, regardless of size
- 5 metres high at the wall with a capacity of 50 megalitres or more
- 10 metres high at the wall with a capacity of 20 megalitres or more
- 15 metres high at the wall, regardless of capacity.
- These dams are regarded as potentially hazardous, and require special operating conditions.
Surveillance and Emergency Management Plan (SEMP)
The SEMP must be prepared by an experienced consulting engineer. It should include as a minimum:
- A summary of the dam properties, current dimensions and other features
- An appropriate dam surveillance program and check list
- A Dam Safety Emergency Plan (see our website)
- Inspection photographs
- Spillway capacity computations
- Locality and catchment plan
- Any recommendations regarding works needed to bring the dam to acceptable standards
Your licence may include conditions such as:
- Submitting monitoring when required by Southern Rural Water
- Remedial works to correect any faults identified by the SEMP
Your Dam Operating Licence is valid for 5 years, and has an annual fee. When your licence is due for renewal, we will send you an application, and you will need to submit an updated SEMP.
Dam maintenance and repairs
A dam is a valuable asset on any property, providing essential water supplies.
If your dam fails, it can lead to:
- Expensive repair bills
- Lost productin whilst your dam is fixed
- Legal liability for any damage caused to people, property or the environment
It makes sense to keep your dam in good repair!
Dam owners often seek advice from Southern Rural Water about their obligations when undertaking works to dams – particularly when a works licence is needed.
This Fact Sheet provides some guidance on when a works licence is required. Remember, it is always best to check with us before you start work.
Your dam spillway must be designed to take a 1 in 100 year flood (technically known as an Australian Rainfall Index rain event). Storms can hit without warning, and a correctly sized spillway is essential protection for your dam. The spillway must never be reduced in size without approval from Southern Rural Water.
Compensation pipe and valve
The valve must be operated regularly to avoid seizure due to rust and other build-up. Regular operation will also reduce the amount of silt and other debris that can build up in the compensation pipe. You should maintain safe and simple access to the valve at all times.
Keep your downstream wall clear of trees, shrubs and weeds. The slope should have an even cover of deep-rooted grass, regularly maintained to allow a visual assessment of the wall.
You can use the crest of the dam for vehicle or stock crossings. However, it should be kept level to avoid pot holes and uneven areas forming. You should also keep your crest fenced to exclude stock from both the upstream and downstream walls. Allowing stock access to the walls will cause damaging erosion.
You should install a straight line of fence posts across the crest and check them regularly. Any movement should be immediately reported to Southern Rural Water and your dam engineer.
You should also regularly check for leaks, wet spots, slumping or any signs that the dam may be at risk. Regular inspections and prompt maintenance will help you get the maximum life span from your dam.
This advice is general in nature, and you should seek expert advice about the best way to keep your dam safe and operating properly.
What is maintenance?
Basic maintenance of a dam does not require a licence from Southern Rural Water. This includes:
- Cleaning out of weeds
- Minor works to repair erosion damage on the crest, embankment or spillway
- Removal of vegetation from the dam wall
- Maintenance of the compensation pipe or trickle pipe
Any modification to the structure of the dam will need a licence! It is always best to check with us before you start work.
You need a licence to construct, alter, operate, remove or decommission any dam that:
- Is located on a waterway
- Has a wall height of 5 metres or higher and a capacity of 50 megalitres or more
- Has a wall height of 10 metres or higher and a capacity of 20 megalitres or more
- Has a wall height of 15 metres or higher, regardless of the capacity.
- Any alteration to the dams holding capacity or wall height
- Modification of the crest, spillway, compensation pipe or trickle pipe
- Reconstruction of the dam wall due to damage – such as damage sustained during a flood
- Repairs that result in disturbance to the embankment – such as removing a section of the embankment to replace or repair a compensation pipe or trickle pipe.1
Getting a licence?
We strongly recommend that before you begin, you make an appointment to have a chat with one of our staff.To obtain a works licence, you must submit:
- An application form (see our website)
- A site plan or location plan
- Appropriate fees (see our website)
Typically, a condition of a works licence will require the dam works to be designed and the construction supervised by a suitably qualified engineer.
Our website has a list of consulting engineers.
Note: a ‘suitably qualified engineer’ means a person eligible for membership of the Institution of Engineers Australia who is able to demonstrate competence in the design, construction supervision and surveillance of dams.Dam Safety Emergency Plan