Report to assist community consultation
The NSW Border Rivers: Floodplain harvesting in water sharing plans – Report to assist community consultation report (PDF, 1101 KB) aims to assist the community in understanding the proposed types of rules for floodplain harvesting access licences in the NSW Border Rivers. It also provides a summary of the other four technical reports and explains the interaction between the rules, modelling, and the expected environmental benefits once they are put in place.
Please note: this report was updated on 20 October 2020 due to an error in Table 7.
A supplementary report which compares the 5-year floodplain harvesting carryover rule with an annual account rule that prevents carryover has been developed. This report details the resulting entitlements and environmental outcomes of both scenarios.
The NSW Floodplain Harvesting Policy sets out a framework for bringing floodplain harvesting into a licensing framework to manage diversions within legal limits. The policy requires that individual entitlements in regulated river systems will be informed by a capability assessment that considers the works used for floodplain harvesting and the opportunity to access floodplain flows based on location and climatic variability. This capability assessment is undertaken through river system models.
The department has developed two reports to describe how this work has been completed. Firstly, 'Building the river system model for the Border Rivers Valley regulated river system' describes the development of the Border Rivers Valley river system model – its conceptualisation, construction, and calibration. The model was developed using multiple lines of evidence and best available industry data. The report provides evidence and assessments to demonstrate that the model has made the best use of available data and methods for implementation of the policy.
Secondly, 'Floodplain Harvesting Entitlements for NSW Border Rivers Regulated River System: Model Scenarios Report' describes how the Source Model of the Border Rivers was used to estimate the baseline diversion limit, and to subsequently estimate individual floodplain harvesting entitlements.
Environmental outcomes reports
Harvesting of water from floodplains reduces the volume, frequency and duration of floods and can change the timing of flood events, impacting the health of floodplains and downstream waterways. To manage unconstrained harvesting, the NSW Floodplain Harvesting Policy will bring floodplain harvesting under a licensing framework to provide a more sustainable level of water diversions from the floodplain.
Hydrological metrics needed to meet recruitment and maintenance needs of native fish, floodplain native vegetation, waterbirds, key ecosystem functions and wetlands were modelled for two scenarios. Implementation of the policy is predicted to improve the number of flow days, frequency, and timing of floods for native fish, waterbirds, and floodplain vegetation.
Environmental outcomes of implementing the Floodplain Harvesting Policy: Border Rivers report provides a detailed assessment of the benefits or disadvantages for the environment of implementing the policy in the NSW Border Rivers Valley.
- Environmental outcomes (PDF, 4.5 MB) of implementing the Floodplain Harvesting Policy in the Border Rivers Valley
Below is a summary of the environmental outcomes predicted for the Border Rivers, Gwydir and Macquarie valleys.
Downstream effects reports
The NSW Floodplain Harvesting Policy establishes a framework for licensing floodplain harvesting activities and managing floodplain diversions in a way that brings them back within statutory limits. The licencing framework will restrict the volume of water that can be taken from the floodplain providing gains to the system through foregone diversion.
Any gains in upstream systems such as the NSW Border Rivers will translate into the downstream with additional volumes originating in each of the Barwon-Darling tributary valleys contributing to connectivity between the broader northern basin system and provision of increased flows towards Menindee and into the Murray River.
Modelled downstream effects of licensing floodplain harvesting in the NSW Border Rivers Valley report quantifies the potential downstream impacts of these increased flows. Subsequent reports will be made available in early 2021 that catalogue the impact of Policy implementation in the other Valleys. Each Valley will be looked at individually with additional analysis of the cumulative impact of licensing floodplain harvesting across the entire northern basin.
Independent peer review
The modelling reports for the Border Rivers Valley has been independently peer-reviewed.
Compliance with water management principles
This document details how the department has complied with the water management principles outlined in the Water Management Act 2000 in the development of the Water Sharing Plan for the Border Rivers Regulated River Water Source 2020.
Rainfall Runoff Exemption Supplementary report
The proposed rainfall runoff exemption has the potential to impact floodplain harvesting modelling in the NSW Border Rivers Valley. The department has proposed a regulation to exempt rainfall runoff that is collected in a tailwater return drain from requiring a water access licence and a water supply works approval. The successful commencement of this exemption will impact floodplain harvesting modelling in the NSW Border Rivers Valley. This report clarifies the scale of this potential impact on licence shares, the environment, and downstream outcomes.
What we heard
The What we heard report (PDF, 414.8 KB) summarises the feedback the NSW Government received during the public consultation sessions and from written submissions for the NSW Border Rivers Valley.
In addition to the final rules detailed in the What we heard report, an additional rule has been proposed that acknowledges the connectivity between the Barwon-Darling Valley and the northern inland tributary valleys, and ensures flows are temporarily protected from floodplain harvesting following a dry period. More information on this rule.