Water Engagement Roundup
The questions and answers from the Water Engagement Roundup webinar recorded on Wednesday 19 February 2025 will be published shortly. The topic for this webinar was 'Minimum inflows for Surface Water planning and Climate and Strategic projects'.
Watch the webinar
19 February 2025 This month's update was on 'Minimum inflows for Surface Water planning and Climate and Strategic projects'.
Questions and answers
A number of questions were asked during the webinar. Those questions that were not addressed in the time available on the day are now available.
Will the department be undertaking a cumulative impact test, modelling the cumulative impact of current and past projects, all with the intent of reducing farmers' access to water in average and wet years. For example, the Connectivity Review, and now more is wanted under the guise of this minimum inflow sequence.
A. The baseline for looking at our impacts is the current water sharing plan which will include past projects. The department will be looking at cumulative impacts from multiple current reform projects and considering this in implementation.
The models might be 'appropriate' for water planning but not tested for efficacy in determining available water determinations (AWD). The Murray Darling Basin Authority (MDBA) has nothing to do with AWD - they're not in the place to provide any advice on this very specific issue.
A. The models estimate AWD in a way that is intended to be consistent with how allocations are undertaken, based on available records. And this representation is used to determine AWD and consequently extractions in a long-term planning sense. The suitability of using the models for these types of shorter-term decisions is one of the questions we have asked of the Office of the NSW Chief Scientist and Engineer to review and provide advice.
Will the department release the previous modelling completed in the Lachlan showing the impacts of changing the minimum inflow sequence? showing both the negative impacts to general security (how the department proposes to compensate for this?) and any proposed benefit and if this is actually deliverable? also have you completed modelling for increased flooding in holding the dam higher including linkages to inundation mapping?
A. The previous modelling will not be used for this work as there have been changes in data and methods since then. The timing of the modelling for Lachlan is as per the schedule from the presentation. The impact assessments will examine economic impacts including on allocations to all licences as well as town water supply. It will also examine environmental impacts. While the modelling does provide some information on spills, the planning modelling is not generally used for flood inundation estimation.
If the department gets it wrong in the Murrumbidgee, or the Border Rivers - what happens then?
A. The department is currently using a short term of record - we do not have perfect information to make sure we are ever right - but we have always had management responses to this - going into critical human needs and drought management if required, or allocating additional water later in the year if we are too conservative earlier.
This is going to have a double impact on irrigators. Less water allocated and higher costs re available water due to climate change. Will there be consideration to pass costs on to the broader community as everyone contributes to climate change in regard to fixed fee relief for irrigators if less water is available?
A. As part of its price determinations, IPART uses the ‘impactor pays’ principle to decide the portion of costs to be recovered from water users through prices and the portion to be paid by Government on behalf of the broader community. In the 2021 WAMC price determination final report (p91), IPART provided information on how it would treat climate change impacts associated with water management.
Visit IPART for more information.
What happens when flows so low there is not enough water for people (urban and town water supply); what happens to fish and rivers and irrigators?
A. The department has an extreme events policy that outlines steps for when flows reach very low levels.
Will High Security water entitlement be impacted by any changes? It’s High security, not absolute security water and reductions could be done reliability so all water users where the pain. What about the wet times where they are also appears to be more extreme.
A. While the current focus of the work the department is undertaking is ensuring town water supplies are secure, the review will also consider the reliability of High Security water users in line with the requirements of the plan.
Will the department be calculating the hit to WaterNSW and Water Administration Ministerial Corporation (WAMC) revenue from water licence holders, and therefore prices, by reducing General Security allocations and other licensed water access under this project?
A. Prices determined by IPART are based on water take forecasts over the price determination period. Actual water take varies from year to year, based on water availability and other factors. In years where water allocations are lower than forecast, WAMC and WaterNSW recover less revenue than allowed for in the price determination.
Which climate change worst case scenario is the department using in the model? Is the scenario RPC8.5? How do the Millennium and Tinderbox Droughts compare to the worst case IPCC scenario? For example, if the Millennium Drought was worse than even the RPC8.5 scenario, which itself is considered unlikely due to its assumptions, and the Millennium Drought is extremely rare, even by climate change scenario standards.
A. The department proposes to use the more recent NARCliM 2.0 results, which uses Shared Socioeconomic Pathways (SSPs), with low, medium and high emission scenarios similar to the RCPs. And to use an estimate of "current" climate change impacts as we have already seen an increase in temperature and consequent increase in evaporation, together with a medium emission scenario which is similar to RCP4.5.
It is not straightforward to compare short-term observed periods against models which estimate changes over longer time periods. Looking further back in history using paleoclimate records there is evidence that there were much longer dry periods centuries ago than anything we have observed in the last 2 centuries. What the climate models are telling us are that there will certainly be higher temperatures which means more drying out of catchments and lower inflows regardless of changes in rainfall. Of itself this temperature increase will make droughts worse. The changes in projections in rainfall are less consistent. Most models project less rainfall as well as changes in seasonality in the south. The changes in the north are less certain.
Why is the data shared in the presentation only up to 2010 and not current? Why are the periods against models which estimate changes are not over longer time periods? From paleoclimate records, there is evidence of much longer dry periods centuries ago than anything we have observed in the last 200 years.
A. The department assesses storage reserve over the period used for the water sharing plans for comparative purposes, which in the case of the Border Rivers is around 2010. We are also assessing these over the full observation period which goes until 2023 which includes the Millenium Drought and Tinderbox Drought. We then take the analysis further using the paleoclimate evidence that the department has prepared for Regional Water Strategies.
The department has had one year of 'claw-back' (buy-back) in the Murray and it has never happened again, based on the current min inflow – where is the driver to change things?
A. As per previous question - using the historic record gives us only a short record to determine the likelihood of extreme events. While the planning is done assuming the worst drought on record corresponds to a roughly 1:100 year likelihood, it could be 1:50 or 1:200 - the record is not long enough for us to be sure. This work aims to give us a better understanding of the level of risk and use this to inform any decisions.
Would any potential reductions in water allocations and compensation fall under National Water Initiative (NWI) clause 48 (risks arising from seasonal or long-term changes in climate) or clause 50 (changes in government policy)?
A. Any compensation requirements will be part of the government's consideration as the reviews proceed.
If the Bureau of Meteorology (BOM) itself says they don't know how warmer oceans will affect weather, how can the department be sure of the impact of climate change (ie. it appears you're assuming 'drier') if they are not?
A. The department’s approach is to acknowledge this uncertainty in climate, at the same time paying closer attention to those climate conditions that will cause problems, which are generally extreme droughts or extreme floods. By understanding the plausibility of these conditions, we will be better prepared for if or when they happen. If they don't happen, even if it turns out to be wetter, then we would expect that water sharing would not be affected compared to current conditions. What the climate models are telling us are that there will certainly be higher temperatures which means more drying out of catchments and lower inflows regardless of changes in rainfall. Of itself, this temperature increase will make droughts worse. The changes in projections in rainfall are less consistent. Most models project less rainfall as well as changes in seasonality in the south. The changes in the north are less certain.
From what the speaker has shared, does that mean the methodology will change based on actual feedback from impacted licence holders?
A. The department will be seeking feedback from stakeholders on the method. The method or the application of the method may change based on stakeholder feedback.
The Murrumbidgee Valley is one of the two trial valleys. How will the allocations be impacted during this trial? What exactly is being trialled? What does the trial in the Murrumbidgee look like in practice? Is it running in the background and, if so, what is it showing?
A. There will be no impacts during the trial. As for any potential rule changes, there will be no changes to the current methods until the water sharing plans are amended. The method and the potential results of its application will be shown during consultation.
Should there be consultation on the 'essential requirements' to be delivered in these extreme droughts? Some water sharing plan commitments are relatively generous, and could consider being restricted in those extreme droughts (eg effluent replenishments, continuous flows to whole systems, high security, translucency, etc). As per some of the measures in the extreme events policy.
A. The available water determinations (AWD) process generally assumes full utilisation of entitlements and there is no proposal to change this as part of this study. In the event of a severe drought it remains an option for drought management, including taking underutilisation into account.
What is the actual driver behind this review? Is it carryover water that was undeliverable in several regulated valleys in 2019 and 2020 drought? How did we survive the last drought, by having access to water in the wet years to build resilience. What has been discussed today will reduce the capacity of farms to buildup reserves to get through tough years.
A. The underlying driver is to seek to understand how frequently the department may need to go into these critical needs management scenarios, and whether we need to review this given anticipated climate change impacts.
When the Regional Water Strategies (RWS) were being consulted on, the department said the paleo and stochastic modelling was not going to be used available water determinations (AWD) - what has changed? I think there needs to be much more engagement with water users about the potential new method at a valley level. In the Murrumbidgee in the slide presented as lowest rainfall on record, the Murrumbidgee was able to meet all of its high priority commitments. There needs to be opportunities for tailoring the method based on the catchment, for example the Murrumbidgee and Murray have drought reserves in Snowy, We need more discussion at a catchment in this project.
A. During consultation it was recognised that the extreme dry scenario 40 years into the future used as a bookend in the RWS was not appropriate for shorter term decision making, but the department is not ruling out using the paleoclimate informed stochastic data if we could establish its suitability. We are proposing to use a much nearer term climate change projections in this process, recognising that the water sharing plan allows for a 10 year review cycle.
There's currently a significant time lag in critical information needed to determine available water determinations (AWD)- which impacts substantially on General Security in particular. Has the Expert Panel been asked to consider this as well?
A. The department has not asked the Expert Panel to review the current available water determination (AWD) process.
Will the process clearly show the differences between current versus new method, not average impacts but, apply the new method to actual current and past years so the impacts are very clear.
A. The department is looking at showing the differences in ways that best represent what stakeholders would like to see. As we don't know what the climate will be in the next ten or more years, we do need to be able to show impacts across a range of climate conditions.
Is the department considering Specific Purpose Access Licences (SPAL), excluded works, harvestable rights in calculations of inflows and are those numbers available
A. All licenced entitlements within a regulated system are accounted for in the available water determination (AWD) process. For unlicensed usage under basic landholder rights, these are either estimated in the AWD process or reflected in the calibration of the models
The probability of the department being wrong with this proposal is very high as there is added significant uncertainty. How can we be confident that this is a step forward rather than a step backwards.
A. What is different in this approach is that the department is accounting for this significant uncertainty, compared to our original approach which did not account for uncertainty. We are less likely to get it right by ignoring uncertainty.
How does the department take into account changes in runoff from rainfall into creeks which can be due to both changes in climate (rainfall vol, intensity and temperature) and to how the large numbers of land managers are trying to increase how much rainfall soaks into their land and goes into plant production?
A. Where these are important for water sharing plan related outcomes, these are accounted for using our water models, which transform climate data to flow data. As part of our ongoing model improvement approach the department will try to account for this impact where we see evidence for this in the flow data. This would require that the uptake of this change in land management practices happened across a large percentage of the catchment area, and we would need a period of data several years long to be able to detect and quantify this change.
Will the department be also assessing the impact on the reliability of Held Environmental Water entitlements (HEW), as this project has high potential to substantially reduce the amount of water available in droughts for maintaining drought refuges etc.
A. Yes, impacts to all water entitlements will be assessed as part of the impact assessment. The held environmental water entitlements are no different to those owned by other water users.
Does the department acknowledge there is a risk in basing decision and management always based on a dry scenario?
A. The department will use multiple scenarios to inform decisions for this project. The decision will not be solely based on using a dry scenario.
Sounds like environmental water holders will have higher priorities than General Security water where a lot of enviro water has come from.
A. Environment water holders have supplementary, general security or high security licences and these are treated the same as all other licences in that category. They do not receive higher priority in the allocations process.
Will first nations have a chance to sign off on these proposals once settled?
A. First Nations will be consulted as part of the consultation for the project. Could the department explain how/what implications for more water in storage and elevated flooding risks.
Could the department explain how/what implications for more water in storage and elevated flooding risks.
A. The department can review changes in dam spill behaviour from the models. While the frequency of these is a robust result the models do not do detail flood operations behaviour which would in some cases modulate the volumes spilled.
Process sounds very conservative as does not include impact on Drought Response Plans on HP requirement?
A. The department’s current proposal is as part of the method we will look at how often the extreme events policy is activated.
What consultation will occur for this work? The webinar is only information sharing and not consultation. Will there be face-to-face consultation?
A. The webinar was an introductory information session to inform stakeholders that the project to conduct the review required by water sharing plan provisions has commenced. A full communication and engagement plan is being developed to ensure stakeholder engagement in the project at multiple stages.
This will include:
- consultation on the method and the Office of NSW Chief Scientist & Engineer expert panel recommendations
- communication statewide of the outcomes of the review in each valley as they are conducted
- face-to-face engagement with stakeholders and impacted water users in each valley on the outcomes of the review in that valley
What is Native title?
A. The Water Management Act 2000 recognises the cultural and spiritual importance of water to Aboriginal people in NSW and recognises Native Title as a form Basic Landholder Right (BLR) (section 55). Anyone who holds native title with respect to water, as determined under the Native Title Act 1993 (Cwlth), can take and use water for a range of needs without needing a water access licence. These include personal, domestic and non-commercial communal purposes such as manufacturing traditional artefacts, hunting, fishing, recreation, cultural and ceremonial purposes.
What volumes of water are associated with Native title?
A. Currently there are no volumes of water associated with the Native title determinations and water usage under Native Title is not understood. The determinations can be found listed online at National Native Title Tribunal. Water sharing plans with Native Title claims will list any determination relating to water in the water sharing plan – see clause 20 of the Barwon Darling Unregulated water sharing plan. It is our understanding that under the Native Title Act 1993 that Native Title Rights cannot be fettered.
Has it always been number one priority?
A. Yes. The Water Management Act 2000 has considered Native Title as a Basic Landholder Right since its inception (s55).
Water sharing plans have always required that water for BLR (basic rights, harvestable rights and Native Title rights) is reserved in the resource assessment as a high priority requirement prior to allocating to lower priority water users, however there is given no volumes of Native Title usage known there is currently not water reserved in the allocation process for this use.
It should be noted that the Native Title determinations that include water specifically do not allow the Native Rights holder the ability to control the use of water. For example the Native Title determination for the Ngemba, Ngiyampaa, Wangaaypuwan and Wayilwan People specifically gives non-exclusive rights to 'the right to take and use the water for their personal, domestic and communal purposes (including cultural purposes) but not extending to a right to control the use and flow of the water in any rivers, streams or lakes'.
This means that a Native Title Right holders cannot call water from a dam or request water be released.
Is bridging the gap water part of Native Title or is that a different class?
A. No, Closing the Gap relates to increasing Aboriginal water rights and providing for Aboriginal access and ownership of water for cultural and economic purposes. The Closing the Gap work is separate to Native Title determinations.
If you need further information please contact us with any additional questions.