Hydrologic Modelling of Connectivity Expert Panel Recommendations 2025–Scenario 4–Connectivity EWA–Dam Inflow Trigger

The Panel recommended that the Gwydir, Namoi and NSW Border Rivers regulated water sharing plans should include a ‘connectivity’ environmental water allowance (EWA) to provide pulses as needed for water quality and other environmental outcomes during dry times. Replenishment releases triggered by the dam inflows falling below the 75th percentile on average over 30 days. Up to two large replenishment releases of 20 GL made each year in each valley triggered by low inflows into storage dams. Release triggered on 31 October and 28 February each year if the inflows to the valley storage dams are less than the 75th percentile. Releases are made to achieve at least a week of flows at Bourke with peak flows above 972 ML/d for up to 10 days and at least 30 GL total event volume.

A connectivity environmental water allowance was not considered for the regulated Macquarie River as it empties into the Macquarie Marshes rather than the Barwon-Darling.


Note: See Analysis of the Connectivity Expert Panel Recommendations: Hydrologic modelling assessment.pdf (attached) for more details.

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Data Source:
  • SEED
Data and Resources
PDF
MetadataStatement_Questionnaire_Scenario 4-connectivity E...
XLSX
Northern Basin Connectivity - Modelling 2025 - Scenario 4...
PDF
Analysis of the Connectivity Expert Panel Recommendations...
Additional Information
Field Value
Title Hydrologic Modelling of Connectivity Expert Panel Recommendations 2025–Scenario 4–Connectivity EWA–Dam Inflow Trigger
Date Published 01/02/2026
Last Updated 01/02/2026
Publisher/Agency NSW Department of Climate Change, Energy, the Environment and Water
Licence Creative Commons Attribution
Update Frequency notPlanned
Temporal Coverage 01/01/1895 - 30/06/2023
Geospatial Coverage
Data Portal SEED