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Engagement – October 2023

Topics from the October webinar were on the NSW floodplain management, including the Northern Valley and Southern floodplain management plans.

Macintyre River.

Water Engagement Roundup

The questions and answers from the Water Engagement Roundup webinar recorded on Wednesday 18 October 2023 are below. The topic for this webinar was the NSW floodplain management, including the Northern Valley and Southern floodplain management plans.

Watch the webinar

Wednesday, 18 October 2023. This month's update was on the NSW floodplain management, including the Northern Valley and Southern floodplain management plans.

Questions and answers

How, and who is responsible, for ensuring floodplain management is planned and enforced so as to comply with the principle objectives under the NSW Water Act 2014 as set down under Clause 6 (1) of the NSW Water Act, especially the requirement “to ensure that declared catchment areas and water management works are managed and protected so as to promote water quality, protection of public health and public safety, and the protection of the environment” (subclause (c))?

A. The department coordinates the preparation of floodplain management plans, which is guided by a technical manual that is published on our website; and this planning process includes the requirement to meet the water and floodplain management principles in the Act.

An Interagency Working Group reviews the plan's key stages of development. This group includes representatives from the department's Environment and Heritage group along with DPI Fisheries, DPI Agriculture.

As part of the approvals process with the Minister for Water and the Minister for the Environment, we must demonstrate that a new FMP meets the water and floodplain management principles of the Act. This decision making process happens for both new plans and for any plan amendments.
WaterNSW is then responsible for assessing flood work applications and NRAR is responsible for compliance and enforcement.

What is the relationship between the department's Water staff and environment agency on the development of floodplain management plans

1. What is the relationship between the department's Water staff and environment agency on the development of floodplain management plans
2. Is there an update on the removal of identified unapproved works from the Northern Basin floodplains
3. What inventory has been taken of unapproved works on the Murray and Murrumbidgee floodplains
4. What risk assessment is there for communities and property


1. We work closely with the Environment and Heritage group throughout the plan development phase - for example, they are are currently working to identify the ecological assets for us for all four southern valleys. They are represented on our Interagency Working Group and their Minister - the Minister for the Environment - must provide concurrence prior to making a new plan or for any amendments to existing plans.

2. NRAR is responsible for compliance and enforcement. However, we are working with NRAR and other partner agencies to deliver the Improving Floodplain Connections project, which aims to fast-track the process of bringing unapproved flood works into compliance across more than 100 priority areas in the northern Basin. We recently (Nov) held a webinar for impacted landholders in the Namoi and Macquarie valleys.

3. As part of development of the FMP, all floodworks are identified and their approval status reviewed, this information will be provided to NRAR when complete. The department will continue to work with NRAR and WaterNSW to bring priority unapproved flood works into compliance.

4. One of the primary objectives of a floodplain management plan is to contribute to the protection of life and property from the effects of flooding. This a requirement in the water management principles of the Act. What a floodplain management plan does is standardise the rules for flood work applications, ensuring that a robust assessment process is applied, including impacts on other floodplain users and the environment.

Has there been an updated audit of licensed/unlicensed levees? Will there be any financial assistance to help realign identified licensed levees that need to be moved?

NRAR is responsible for compliance and enforcement of flood works, including levees. During the development of a FMP all floodworks are identified and their approval status reviewed. This information is provided to NRAR when complete.

Unapproved flood works were a key issue raised during our information sessions in June, and further information is available in the what we heard report published on the Healthy Floodplains website.

Levees that have an approval will not be realigned as part of the process to develop new FMPs. The new plans are statutory instruments which set the rules for flood works. They will not include actions to deal with problem areas. We acknowledge that further work will need to be done in this space, however, our priority is setting clear and consistent rules across the whole floodplain.

The reduction of harvestable right water storage on the eastern coast of NSW was not given any prior consultation with water licence holders

On 27 September, the harvestable rights limit for coastal-draining catchments was reduced to 10% of rainfall runoff. Landholders who had legally started works to increase their harvestable right up to 30% before the limit was reduced back to 10% can retain their increased harvestable rights dam capacity.

The timing to inform landholders of the change in the coastal harvestable rights limit was chosen to prevent further uptake of the increase harvestable rights limit, and reduce unquantified risks to the environment and downstream water users.

Will all Floodplain Management Plans be updated post recent statewide floods, please?

Rural floodplain management plans prepared under the Water Management Act for inland areas of the state undergo periodic review during their 10-year term. Not all plans can be updated at once as they are very large in scale. The current focus is the replacement of the 10 plans in the southern Murray-Darling Basin. We are using information from the 2022 floods to inform the development of the new valley-wide plans.

What compromises an enhancement work?

An enhancement flood work could be a low level training bank to direct flood flows into a wetland or lagoon that has ecological or Aboriginal cultural significance and requires regular flooding to maintain it's value.

On Enhancement work - how do you define 'positive' in terms of positive outcome?

The department is replacing the former terminology with 'positive' to be a more specific reference to the improving of floodplain connectivity to flood-dependent ecological or cultural assets. In simple terms, a 'positive' outcome needs to have demonstrate an improvement in flood connectivity.

Could you expand a bit on the relationship between DPE-Water staff and the environment agency on the development of floodplain management plans?

We work closely with the department's Environment and Heritage Group to develop floodplain management plans as they are the experts in the identification and protection of ecological assets such as wetlands on the floodplains.

The Environment and Heritage Group is also represented on our Interagency Working Group who will review the draft floodplain management plan at key stages of development, particularly prior to public consultation.

What is the timetable for the assessment of unapproved works on Murray and Murrumbidgee floodplains?

Hydraulic model development in the Murray and Murrumbidgee valleys is well underway. This includes the identification of all flood works on the floodplain. We are preparing for our first stages of public consultation in these valleys in early 2024. We will continue to liaise with NRAR during this time.

Is building levee banks on your own property to divert water away from assets during flooding considered enhancement work?

The department would likely not consider this to be an enhancement flood work. A key objective of a floodplain management plan is to facilitate the orderly passage of floodwater across the floodplain. An enhancement flood work would be the opposite, where you build a work to direct water towards an ecological asset rather than away from it.

There's a process to follow to build a levee bank to protect infrastructure like houses and sheds. If a flood is imminent and you want to build a levee bank you will require a flood work approval, and should apply beforehand as part of your flood preparation, typically through WaterNSW.

Under the Water Management Act 2000 all flood works require an approval regardless of when they were built. There are some exemptions for areas outside of high risk floodways. More information about flood work approvals and exemptions is available on WaterNSW's website.

Who does the hydraulic modelling for floodplain management?

The department is leading the development of hydraulic models for the replacement floodplain management plans in the southern basin valleys. We have a broad cohort of hydraulic modellers working on the plans, including a range of external consultants and internal modelling staff within the department's Environment and Heritage Group, the Manly Hydraulics Laboratory as well as our own Water Group.

What is the intention when a stock water channel that has been in existence for over 150 years and has never been required to be registered before? Channel has been there and not had to ever have a work approval. Will they now have to have a work approval even though after 100 years the environment has established itself around it? Is it inappropriate to use the 2022 floods as it was an unprecedented event, with Murray and Murrumbidgee both flooding and 9-11 inches of rain on top of that. How are major floods incorporated into modelling? 

(a) All flood works require a flood work approval unless an exemption applies.

A flood work is defined under the Water Management Act 2000 as a work, such as an embankment, that is:

  • situated in or near a river, estuary or lake, or within a floodplain, and
  • is likely to have an effect on the flow of water to or from a river, estuary or lake, or distribution or flow of flood water in times of flood.

A flood work includes all associated pipes, valves and metering equipment.

There are some exemptions to requiring a flood work approval, such as an embankment around a house, shed or silo, subject to conditions.

A flood work is any work that impacts the flow of flood water to or from a river or the behaviour of the flood plain. All flood works require an approval. Find out more on our website https://water.dpie.nsw.gov.au/licensing-and-trade/flood-works-approvals

To find out if a work approval is required, contact WaterNSW on enquiries@waternsw.com.au, telephone 1300 662 077 or visit their website.

(b) It is important to calibrate the hydraulic models in the southern floodplain valleys to include the 2022 flood event, as it is a large flood in the 'living memory' of the community. The department was able to capture significant data to assist in calibrating the hydraulic models from that event.
In terms of the design event, that hasn't been finalised yet. It is yet to be decided if we use the 2022 flood as the basis for design in the floodplain management plan, once the model results are considered. We will seek public feedback on the design flood events in early to mid-2024.

The timelines seem very general, more like 'ongoing' - can you be more specific re assessment of structures on floodplains, and removal/enhancement as deemed necessary? What are the priorities in terms of floodplain structure assessment and action to enhance/remove?

In the northern valleys priority areas were selected after an extensive assessment. The prioritisation process identified those locations where action under the program could produce the most benefit for floodplain connectivity. Prioritisation included analysis of hydraulic, ecological, and cultural impact. These impacts were assessed as part of a multi-criteria analysis.

As the program progresses, additional areas of concern may be prioritised for possible inclusion and for the notice of NRAR (Natural Resources Access Regulator).

Visit Improving floodplain connections program.

Is the modelling incorporating any forward-looking projections of the worsening extremes of flood events due to ongoing anthropogenic climate change? So new infrastructure can be built to meet current and future needs.

Climate change will be incorporated into all government departments as an election priority by the recently elected NSW Labor government. To ensure consistency of climate change modelling in this department, flood plain management works closely with various teams, including climate change and urban floodplain management planners. The general approach is yet to be finalised, but will develop sensitivity analysis with the hydraulic model by increasing the flows in lines with climate change projections, and then examining what impact that might have.

What triggers retrospective approval of floodworks?

All flood works require an approval, regardless of when they were constructed.

NRAR has substantial capabilities to identify structures and work through satellite images and remote sensing. What happens to historical illegal structures, which will have been removed before they could be catalogued/ licenced under the current initiative. Will there be any retrospective breach prosecution, or does illegality essentially start from the current initiative and thereafter?

Answered by Lisa Stockley, Director - Investigations and Enforcement at NRAR:

NRAR investigates allegations re unauthorised structures in accordance with the requirements in place at the time. Assessment of what enforcement action is appropriate is dependant on a number of factors (including environmental harm) as outlined in our Regulatory Policy.

Please clarify that the department is the lead agency for consultation on these flood plain management plans. In the past the environment agency seemed to do the consultation - that was the case in Macquarie a few years ago

Yes, the Water Group is the lead agency. The team that was undertaking the work from Environment and Heritage Group in the northern floodplains is now providing services to the Water Group.

Previous FMPs recognised floodways re controlled works. Will this continue?

One of the key components or steps in developing the new floodplain management plans is considering the previous planning arrangement, it cannot be said that the floodways that were in the previous plan would not change, but it's definitely a key consideration noting that the development has occurred around those floodways over the past 15-20 years at least.