Frequently asked questions about the approval and construction of farm dams.
What is a Farm Dam?
Within the Wollondilly Local Environmental Plan 2011 dams are defined as:
Water storage facility means a dam, weir or reservoir for the collection and storage of water, and includes associated monitoring or gauging equipment.
Note: water storage facilities are part of a water supply system, as defined in the Local Environment Plan.
Frequently Asked Questions
Farm Dams Fact Sheet
Download the Farm Dams Fact Sheet for all information.
Do I need approval for my dam?
Where permitted, all new farm dams require a Development Application (DA), as does any alteration work (excluding the cleaning of silt).
A licence, under the Water Management Act 2000 (Water NSW), will be required if your dam exceeds the maximum harvestable rights capacity (MHRDC) unless it meets one or all of the following exemptions:
- The dam was constructed before 1 January 1999.
- The dam is less than one (1) mega litre in volume (a standard Olympic-size swimming pool contains approximately 2.5 mega litres) and the lot on which the DA is situated which was approved for subdivision prior to 1 January 1999.
- The dam meets one of the specific exemptions in the Water NSW guidelines.
What are Harvestable Water Rights?
Under the Water Management Act 2000, harvestable rights allows landholders in most rural areas to collect a proportion of the run-off on their property and store it in one or more farm dams up to a certain size. For more information, consult Water NSW’s website.
What else do I need to provide for my DA?
You will need to submit your Development Application via the NSW Planning Portal. Further assistance can be found on our Preparing a DA page.
Specific requirements for dams include:
- Completed Development Application Form
- Payment of relevant fees
- Site Plan with the location of the Dam and all other structures
- Site Analysis Plan
- A survey plan of the immediate area around the proposed dam.
- Detailed plan of the dams size and dimensions
- Two cross sections of the dam drawn at right angles to each other (to show the depth and shape of the dam).
- A Statement of Environmental Effects (see separate fact sheet)
- A copy of the Maximum Harvestable Rights Dam Capacity calculation
- If a licence is required then a referral to Water NSW will be required, the application will be referred and a fee is payable via the Planning portal.
- If located within a water course or a mapped by Natural Resources Water (NRW) a referral to Natural Resources Access Regulator (NRAR) is required. The application will be referred and a fee is payable via the Planning portal.
Where are dams not permitted?
Dams are prohibited in the following land zones:
- B5 (Business Development)
- SP2 (Infrastructure)
- E1 (National Parks & Nature Reserves)
What technical guidelines are there for constructing dams in Wollondilly?
The technical guidelines for the construction of farm dams can be located in the Wollondilly Development Control Plan 2016, Vol. 8, Sec. 3.6 (Earth Dams). The purpose of these controls is to ensure:
- Dams are constructed to a safe standard and
- Minimise the impact of dam construction on neighbouring properties and on the surrounding natural environmental features.
At the completion of the construction of the dam it will be require that certification from a registered surveyor that the dam does not exceed the approved capacity. Certification from a Geotechnical Engineer may also be required as a condition of consent if the dam is location in an area of unstable land. This is to ensure that the dam construction has been carried out in accordance with the technical requirements and the conditions of approval.
For further questions please contact our Duty Town Planner on (02) 4677 1100.
Works within a water course
Any works within 40 metres of a water body will require a DA. It is recommended you speak to the duty planner to confirm the proposed works require no approval.
Do I need a DA to remove Silt from the bottom of my Dam?
No approval is required to removal the silt from an existing dam. This silt or sludge must be disposed of on the property. The works must not increase the dam’s capacity from the original approval or constructed size. It is recommended you speak to the duty planner to confirm the proposed works require no approval.
Do I need a DA to fix a leak in my Dam?
No approval is required to fix a leak in a dam as long as the following items are complied with:
- No fill is brought onto the site outside of the maximum amount permitted without an approval (see next question).
- The material to fix the dam is gathered from the site the dam is located on.
- The repair works must not increase the dam capacity.
Note: Many dams within Wollondilly have been constructed with the materials available on the site. As such these dams have existing material on the site that can be used to fix a leak, broken wall, etc. It is recommended you speak to the duty planner to confirm the proposed works require no approval.
Do I need approval to increase the Dam capacity?
Any works that result in the increase of a Dam capacity will require a DA.
Do I need a DA to fix a leak in my Dam if I bring Material to the site?
If material is not able to be harvested from the site to fix a dam up to 100 cubic metres of clean and certified material is permitted to be brought to the site without approval. Any works that require more material will require development consent.
It is recommended you speak to the duty planner to confirm the proposed works require no approval.