Namoi Valley floodplain harvesting licensing and rules

The Namoi: Floodplain harvesting in water sharing plans – Report to assist community consultation report (PDF, 3219.31 KB) aims to assist the community in understanding the proposed types of rules for floodplain harvesting access licences in the Namoi Valley. It also provides a summary of the other technical reports and explains the interaction between the rules, modelling, and the expected environmental outcomes once they are put in place.

The NSW Floodplain Harvesting 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.

Building the river system model (PDF, 11989.42 KB) for the Namoi Valley regulated river system describes the development of the Namoi Valley river system model. 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 is fit for purpose.

Floodplain Harvesting Entitlements for Namoi Regulated River System: Model Scenarios Report describes how the Namoi Valley river system model was used to estimate the extraction limit, and to subsequently estimate individual floodplain harvesting entitlements.

• Building the river system model for the Namoi Valley regulated river system (PDF, 11989.42 KB)
• Floodplain Harvesting Entitlements for Namoi Regulated River System: Model Scenarios Report (PDF, 742.37 KB)

The modelling reports for the Namoi have been independently reviewed and found to be “the best currently available for undertaking both growth in use and floodplain harvesting entitlement assessments”. To assist in the review, the department prepared an addendum to the Namoi Model Build Report (PDF, 8147.35 KB).

Harvesting 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. The NSW Floodplain Harvesting Policy will provide a more sustainable level of water diversions from the floodplain.

Hydrological metrics and environmental flow requirements (EFRs) for fish, floodplain native vegetation, waterbirds, key ecosystem functions and wetlands were modelled. Implementation of the policy is predicted to provide minor environmental improvements in the Namoi Valley.

The technical report (PDF, 10988.83 KB) below provides a detailed assessment of the likely benefits for the environment of implementing the policy in the Namoi Valley.

• Environmental outcomes of implementing the Floodplain Harvesting Policy in the Namoi Valley: technical report (PDF, 10988.83 KB)

The NSW Floodplain Harvesting Policy will restrict the volume of water that can be taken from the floodplain, providing gains to the system through foregone diversions.

Any gains in upstream systems such as the Namoi Valley will translate into the downstream with additional volumes contributing to connectivity between the broader northern Basin system and provision of increased flows towards Menindee Lakes and into the Murray river.

The report below quantifies the potential downstream impacts of these increased flows. This report includes work completed for the NSW Border Rivers, Gwydir, Macquarie, and Barwon-Darling valleys.

• Modelled downstream effects of licensing floodplain harvesting (PDF, 4458.84 KB)