Overview

The Reconnecting River Country Program is investigating ways to improve environmental water delivery throughout the Murrumbidgee Valley by reducing or removing flow constraints that limit connectivity between rivers, wetlands, and floodplains. This project focused on assessing how different environmental flow scenarios could benefit native wetland fauna and improve the ecological health of the broader river system.

The assessment provided scientific evidence to support future water management decisions and ecosystem restoration initiatives.

The Challenge

Many wetlands and low-lying floodplains within the Murrumbidgee Valley are disconnected from natural flow events due to existing river constraints. This reduced connectivity limits the frequency of inundation, affecting the health of ecosystems that depend on regular flooding and diminishing habitat availability for native flora and fauna.

The challenge was to understand how modifying flow constraints could improve environmental outcomes while balancing the broader management of the river system.

Our Approach

The project assessed the ecological implications of four environmental flow scenarios, including:

• The existing (base case) flow regime
• Three alternative scenarios with progressively relaxed flow constraints at Wagga Wagga

The analysis evaluated how each scenario would influence the Murrumbidgee River and Yanco Creek systems, with a particular focus on:

• Native wetland fauna habitats
• Wetland and low-level floodplain connectivity
• Frequency and extent of environmental inundation
• Broader ecosystem responses across the river landscape

The study formed part of a wider suite of environmental assessments and complemented parallel investigations into floodplain tree health and native fish responses to constraint management.

Key Findings

The assessment demonstrated that reducing flow constraints has the potential to significantly improve ecological connectivity across the Murrumbidgee Valley.

Key findings included:

• Relaxed flow constraints would allow environmental water to reach a greater number of wetlands and low-level floodplains more frequently.
• Improved hydrological connectivity would enhance habitat availability for native wetland fauna across the river system.
• Different flow scenarios produced varying ecological outcomes, providing valuable insights for future environmental water planning.
• Integrating fauna assessments with studies on floodplain vegetation and native fish offers a more comprehensive understanding of ecosystem-wide responses.

Outcome

The project delivered an evidence-based assessment of how alternative environmental flow strategies could support healthier, more connected wetland ecosystems throughout the Murrumbidgee Valley.

The findings help inform future decisions on flow constraint management, supporting restoration efforts that improve biodiversity, strengthen ecosystem resilience, and enhance the effectiveness of environmental water delivery.

Impact

This assessment supports long-term river and wetland restoration by:

• Evaluating the ecological benefits of alternative environmental flow scenarios
• Improving connectivity between rivers, wetlands, and floodplains
• Enhancing habitat for native wetland fauna
• Supporting integrated ecosystem management alongside vegetation and fish assessments
• Providing scientific evidence to guide future environmental watering and river management decisions

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