Size of harvestable rights dams
How is the maximum harvestable right dam capacity calculated?
The maximum harvestable right dam capacity (MHRDC) for a landholding is calculated using the WaterNSW Maximum Harvestable Rights Dam Capacity Calculator. The MHRDC is based on the size and location of a landholding. A harvestable rights multiplier is applied to each landholding. It varies across the state as it considers factors such as regional evaporation, rainfall rates and patterns and assumed demands on harvestable rights dams.
How do I determine the capacity of existing harvestable rights dams on my landholding?
An important part of determining a landholder’s ability to construct new dams or enlarge existing dams is the estimation of the capacity of dams currently on a landholding.
The instructions below provide a simple method to estimate dam capacity. If any of the dams are greater than 10 megalitres in capacity, then you will need to do a more accurate calculation to determine the dam’s capacity.
If you require further assistance with these calculations, please contact WaterNSW on 1300 662 077 or Customer.Helpdesk@waternsw.com.au in the first instance.
- Decide the shape of the dam from the options above.
- Measure the relevant width and length at top water level and record these numbers. All dimensions need to be recorded in metres.
- Measure the maximum depth of the dam and record this number.
- Use the formula relevant to the dam shape above to calculate surface area in square metres of each dam and record the results.
- Using the following formula for all dam shapes, calculate the volume in cubic metres.
Volume = 0.4 x Surface Area x Depth Record the results.
Note: The conversion factor of 0.4 considers the slope of the sides of dams. - Divide this volume by 1000 to convert cubic metres to megalitres. This is the dam capacity in megalitres (ML).
If you have existing dams on your landholding that are mixed-rights dams (that is, they capture rainfall runoff under the harvestable right but also store other water lawfully taken from a water source), then you will need to contact WaterNSW to get assistance with calculating the harvestable rights volume within the dam.
Does my maximum harvestable rights dam capacity change if I subdivide or sell part of my property?
Because the maximum harvestable right dam capacity (MHRDC) is directly related to the size of your landholding, when you subdivide or sell part of your landholding, your MHRDC is reduced proportionally. For example, if you sell half of your landholding, your MHRDC is halved.
If your landholding is being subdivided, then some of the resultant smaller landholdings may have dams that are greater than the revised MHRDC for that new landholding size. You will need to reduce the size of those dams or apply for works approvals for the dams and obtain a water access licence for the volume of water that exceeds the revised MHDRC. There is no guarantee that the licence or approval will be issued.
It is recommended that you contact WaterNSW before finalising plans for subdividing or selling part of your landholding.
Do I have to measure or meter harvestable rights water?
No, harvestable rights water use does not need to be measured. Each landholding has a maximum harvestable right dam capacity (MHRDC) which represents a percentage of rainfall runoff. The MHRDC is the volume of water that can be legally captured and stored on a landholding under harvestable rights. If a harvestable rights dam is constructed within the limits and the water captured by the dam is used in accordance with the harvestable rights rules, then there is no constraint on the number of times the dam can be emptied and refilled by rainfall runoff and no requirement for water taken by the dam to be recorded and reported.
Constructing harvestable rights dams
Do I need any approvals from WaterNSW or the Natural Resources Access Regulator (NRAR) to build a new harvestable rights dam?
You do not need a water access licence, water supply works approval, water use approval, or controlled activity approval under the Water Management Act 2000 to build a harvestable rights dam, provided you meet the requirements set out in the relevant harvestable rights order.
You may, however, need approvals under other legislation before you can build or enlarge dams.
See ‘Do I need development consent or other approvals to construct a new harvestable rights dam or enlarge an existing dam?’ and ‘Do I need a licence or approvals if I have a mixed-rights dam?’
Do I need a water access licence or approvals if I have a mixed-rights dam?
Yes, in some cases. Mixed-rights dams are dams that capture and store harvestable rights water as well as other water that has been lawfully taken from a water source (such as under another form of basic landholder right, a water access licence or some form of exemption). Contact WaterNSW for more information on licensing and approvals required for mixed-rights dams and determine what will be needed based on your specific circumstances.
Do I need development consent or other approvals to construct a new harvestable rights dam or enlarge an existing dam?'Â
The requirement to obtain planning consent for dams – classed as a ‘water storage facility’ – differs between local government areas according to rules in the relevant Local Environment Plan.
In some areas, even if a development consent for a water storage facility is required, some types of dams do not need development approval if they are classed as ‘exempt development’. The criteria that councils put in place for when a dam is considered ‘exempt development’ varies; it may not be based solely on volume but the height and thickness of the dam wall to ensure dam safety.
Contact your local council or refer to the relevant Local Environment Plan to find out what rules apply in your area.
Landholders should also be aware of and seek any other approvals that may be applicable under legislation such as the:
- Environmental Planning and Assessment Act 1979 (contact your local Council)
- Fisheries Management Act 1994
- Crown Land Management Act 2016
- Biodiversity Conservation Act 2016
- Coastal Management Act 2016.
Where can I build a harvestable rights dam?
Harvestable rights dams can be constructed on minor streams, hillsides and gullies. Minor streams include non-permanent first- and second-order streams determined using the Strahler stream ordering system. The Strahler stream ordering system is described in the image and instructions below. Fact sheets are also available.
Landholders need to use the Water Management (General) Regulation 2018 Hydro Line spatial data to identify minor streams on their landholding.
The Strahler system considers the following in determining the stream order of a watercourse:
This pattern continues to form higher order streams. |
Figure 2. The Strahler stream ordering system.
Where can’t I build a harvestable rights dam?
For landholdings in the coastal-draining catchments and central inland-draining harvestable rights areas, dams cannot be built (as at the time of construction or first use of the harvestable rights dam):
- on, in or within 40 metres (measured perpendicularly) of any stream that is not a minor stream
- on or within 3 kilometres upstream, including within stream and within the catchment generally of, a Ramsar wetland. Ramsar wetland sites in NSW are available.
For landholdings in the Western Division of NSW, harvestable rights dams cannot be built on:
- a stream classified as a third or higher order stream
- land depicted on certain topographic maps as land subject to flooding or inundation, or lakes shown on those maps as Perennial or Intermittent
- land on or within 3 kilometres of a Ramsar wetland.
Can I build a leaky weir instead of a dam to capture and store harvestable rights water?
No. Harvestable right orders only allow dams to be constructed to capture harvestable rights water. No other type of water supply work or structure may be used to capture harvestable rights water.
How do I split the capacity of a harvestable rights dam that straddles two or more landholdings?
Apportion the capacity of the dam between each landholding in proportion to the surface area of the water stored on the respective landholding when the dam is full.
What can I use my harvestable rights water for?
Landholders located in the central inland-draining and Western Division can use their harvestable rights water for any purpose, unless it is captured and stored in a mixed-rights dam.
For landholders located in the coastal-draining harvestable rights area:
- Water captured and stored in a harvestable rights dam (or dams) with a combined capacity not exceeding the dam capacity which represents 10% of rainfall runoff for the landholding, can be used for any purpose.
The online Maximum Harvestable Rights Dam Capacity Calculator will tell you the capacity with reference to 10% of rainfall runoff, so you will know what this level is for your landholding. - Water captured and stored in harvestable rights dams with a combined capacity greater than the dam capacity which represents 10% of rainfall runoff from the landholding (and up to the previous maximum harvestable rights dam capacity with reference to 30% of rainfall runoff) can only be used for:
- domestic consumption: means consumption for normal household purposes in domestic premises situated on the land
- stock watering: means the watering of stock animals being raised on the land, but does not include the use of water in connection with the raising of stock animals on an intensive commercial basis that are housed or kept in feedlots or buildings for all (or a substantial part) of the period during which the stock animals are being raised
- extensive agriculture: means the:
- production of pasture or and fodder crops for the primary purpose of feeding livestock
- care of livestock, not including livestock raised on an intensive commercial basis that are housed or kept in feedlots or buildings for all (or a substantial part) of the period during which the livestock are being raised.
See ‘If I store water in a mixed-rights dam, can I use it for any purpose?
Why do I need a separate dam or dams if I chose to take up the 30% right when it was available but want to keep a portion of harvestable rights water that can be used for any purpose (in coastal-draining catchments)?
The rules need to be enforceable and we wanted to make it as easy as possible for landholders to understand and follow the requirements of the harvestable rights order. By keeping water that can be used for any purpose in a separate dam, it made it easier to show the Natural Resources Access Regulator (NRAR) that you are complying with the limitations on the use of water taken in harvestable rights dams above the 10% capacity threshold.
This arrangement avoids the need for government to impose requirements for landholders to closely measure and record the amount of water stored in a harvestable rights dam and used from that dam.
*NRAR is the independent agency responsible for the enforcement of water laws in NSW through monitoring, compliance and education.
If I store water in a mixed-rights dam, can I use it for any purpose?
The permitted use of water in a mixed-rights dam will depend on the licence, rights or exemption used to capture and store the non-harvestable rights water in the dam.
In the central inland-draining and coastal-draining catchments harvestable rights areas water can only be used for domestic consumption and stock watering if the other water in the mixed-rights dam is captured under the following circumstances:
- in the exercise of a domestic and stock right under section 52 of the Water Management Act 2000
- under a domestic and stock access licence or a licence granted under Part 5 of the Water Act 1912 for stock and domestic purposes
- under an exemption provided for in clauses 6 and 7 of Schedule 1 to the Water Management (General) Regulation 2018.
Can I move water from my harvestable rights dam to other dams on my property?
In the central inland-draining and coastal-draining catchments harvestable rights areas, water cannot be moved from a harvestable rights dam to any other dam on the property, including an ‘excluded works’ dam or a turkey’s nest dam.
Landholders in these two harvestable rights areas can move water between harvestable rights dams only if those dams have the same permitted uses rules applied to them (i.e. you cannot transfer water from a harvestable rights dam that can be used for any purpose to one that can only be used for stock consumption, stock watering and extensive agriculture – and vice versa).
Why weren’t harvestable rights extended to third-order streams?
Third-order streams are generally larger streams that are more likely to provide permanent flows to rivers. Allowing harvestable right dams on third-order streams would have a much greater effect on downstream flows than dams on minor streams.
Some water sharing plans allow for dams to be located on third-order streams subject to approvals and/or licences that enable dam-specific assessments and conditions to manage the higher risks posed by such dams.
Changes made in September 2023
When was the harvestable rights limit for coastal-draining catchments returned to 10% of rainfall runoff?
On 27 September 2023.
Where can I find the new coastal harvestable rights order and central inland-draining harvestable rights order and what do they do?
The Harvestable Rights (coastal-draining catchments) Order 2023 and Harvestable Rights (central inland-draining catchments) Order 2023 which commenced in September 2023, can be found on the NSW Legislation website at the links above.
The Orders set the rules for capturing, storing and using harvestable rights water in the coastal-draining and central inland-draining harvestable rights areas.
Where can I find the previous coastal harvestable rights order?
The Harvestable Rights (coastal-draining catchments) Order 2022 can be found on the NSW Legislation website.
Why was the harvestable rights limit for coastal-draining catchments returned to 10% of rainfall runoff in September 2023?
The harvestable rights limit for these catchments was returned to 10% (from 30%, which was in place since May 2022) so work can progress on determining whether the current levels of water extraction (considering all forms of water take) in coastal water catchments are sustainable in the long-term.
It is important this work on sustainable extraction is progressed before any increase to harvestable rights is considered. If the harvestable right limit was left at 30%, there could be unquantified negative impacts on other water users and downstream environments.
This Sustainable water extraction in coastal catchments fact sheet PDF, 103.02 KB provides more information on the work to determine sustainable extraction in coastal catchments and how this relates to coastal harvestable rights.
What other updates were made to the harvestable rights rules for coastal-draining and central inland-draining catchments in September 2023?
Updates were made to ensure the harvestable rights rules can be interpreted and applied as they were intended.
Several implementation issues were identified since new harvestable rights orders commenced in May 2022. These issues made the rules difficult to apply and enforce. Some of the rules in the previous harvestable rights orders didn’t do what they were meant to do in practice.
The updates made in September 2023 address these issues and make it easier for landholders to understand what they can and cannot do and help regulators to monitor and enforce compliance with the rules.
The specific updates are summarised in the table below.
| What the update does | What it means for landholders |
|---|---|
Prevents major streams that become undefined (no clear bed and banks) and then reform further downstream from being misclassified as a minor stream | Harvestable rights dams can be built on non-permanent minor streams, hillsides and gullies. They cannot be built on major streams (third order and above – see our factsheets for more information). This update helps landholders to correctly identify major streams and prevents harvestable rights dams from being built where they shouldn’t. |
Allows landholders to construct new harvestable rights dams on declared floodplains | This update makes the rules consistent for all landholders, whether they are on a floodplain or not. Harvestable rights dams are unlikely to cause any significant impacts on the flow of water across a floodplain. In rare instances where they do, the landholder will be required to obtain a flood work approval. This is an existing requirement under the Water Management Act 2000. |
| Prevents landholders and occupiers from both capturing the allowed percentage of runoff from one landholding as a harvestable right (i.e. double counting) | Landowners and occupiers of the same piece of land cannot both capture and store rainfall runoff as a harvestable right from that one landholding. |
| Prevents landholders from using two or more non-contiguous parcels of land in the same harvestable rights area to calculate their maximum harvestable right dam capacity | Landholders cannot group two or more parcels of land that do not share a common border (unless separated by a road or watercourse) into one ‘landholding’ and claim the same harvestable right across these landholdings. This stops landholders from using parcels of land that are separated to calculate their harvestable rights and then build all the dams in one location, causing greater downstream impacts. |
| Clarifies when a water access licence or works approval under the Water Management Act 2000 is required for a mixed-rights dam | A mixed-rights dam holds water captured under a harvestable right as well as water taken under another right or licence. This update makes it easier for landholders to determine whether they need to get a licence or approval for their mixed-rights dam. |
| Allows any landholders who retain harvestable rights dams above the 10% limit, to transfer water between smaller harvestable right dams that can be used for any purpose | Landholders who legally built larger dams under the previous 30% limit will be allowed to retain these dams but must only use the water captured in these dams for stock watering, domestic consumption and extensive agriculture. Like other landholders they can still use the water in their smaller harvestable rights dams (i.e. dams up to the 10% harvestable rights dam capacity for their landholding) for any purpose. This update allows these landholders to transfer water between their smaller harvestable rights dams (just like other landholders), providing greater flexibility in how they manage water on their landholding. |
What happens if I previously submitted a notification form to construct a larger harvestable rights dam or convert an existing dam into a harvestable rights dam (>10%)?
If you had not commenced construction works before 27 September 2023, regardless of whether you submitted a coastal harvestable rights notification form, you must comply with the 10% harvestable rights limit in the new order. You cannot commence new construction works on or after 27 September 2023.
If, before 27 September 2023, you constructed or commenced construction of a new or enlarged harvestable rights dam to capture up to the previous 30% limit, in accordance with the previous Order, you may be able to retain this dam as a harvestable rights dam (refer to paragraph 10 and the definition of Preserved landholding in the new Order). The previous Order required a notification form to be submitted within 28 days of construction commencing.
If, before 27 September 2023, you converted an existing dam into a harvestable rights dam to capture up to the previous limit of 30%, in accordance with the previous order, you may be able to retain this dam as a harvestable rights dam. The previous Order required a notification form to be submitted before conversion of an existing dam commenced.
For these landholders and their harvestable rights dams, the rules about the purposes for which water may be captured, taken, stored or used remain unchanged. Visit NSW Legislation for more information.
For more information, please refer to the ‘Prescribed landholding’ definition in the new Harvestable Rights (coastal-draining catchments) Order 2023 on the NSW Legislation website.
Why can't I access the notification form?
The coastal harvestable rights notification form is now closed.
If you have any specific questions about the notification form or changes to coastal harvestable rights, you can contact Water Enquiries at water.enquiries@dpie.nsw.gov.au or by calling 1300 081 047.
When was a notification form required under the previous 30% harvestable rights limit for coastal-draining catchments?
A form had to be submitted:
- within 28 days of commencing works to construct a dam, including building a new dam or enlarging an existing dam, that would result in more than 10% of rainfall runoff being captured and stored on a landholding as a harvestable right
and/or - before converting an existing dam on the landholding to a harvestable rights dam that would result in more than 10% of rainfall runoff being captured and stored on the landholding as a harvestable right.
If you did not submit a notification form in accordance with the previous Order, any dams constructed or converted will not be harvestable rights dams and regulatory action may be taken unless the appropriate approvals or exemptions are in place.