Overview

Flood events play a vital role in sustaining healthy wetland ecosystems by replenishing nutrients, supporting aquatic food webs, and creating habitat for wildlife. This project investigated how the large unregulated flood of 2022–23 influenced food resource availability and waterbird communities across the Hattah Lakes over the following two years.

The findings provide valuable insights to support future environmental flow management and invasive carp control strategies.

The Challenge

Environmental flooding can dramatically alter wetland ecosystems, but understanding how these changes affect food availability and waterbird populations over time is essential for effective management. While flood events often improve ecological productivity, responses can vary across different lakes and habitats.

The challenge was to evaluate how the 2022–23 flood influenced ecosystem productivity and determine how these changes could inform future environmental watering decisions.

Our Approach

The project examined ecological responses across the Hattah Lakes following the major flood event, with a focus on the relationship between food resources and waterbird communities.

The assessment investigated:

• Changes in flood-driven food webs
• Nutrient and organic matter inputs following the flood
• Fish production and abundance
• Waterbird distribution and habitat use over the subsequent two years
• Differences in ecological productivity between individual lakes

By analysing these interconnected ecosystem components, the study provided a broader understanding of how flooding supports wetland biodiversity.

Key Findings

The assessment demonstrated that the 2022–23 flood substantially increased ecosystem productivity throughout the Hattah Lakes.

Key findings included:

• The flood delivered significant volumes of organic matter and nutrients, stimulating aquatic food webs.
• Increased productivity supported higher fish populations, providing an important food source for waterbirds.
• Diverse floodplain habitats created by the flood attracted and sustained large numbers of waterbirds across the landscape.
• Productivity varied between lakes, highlighting the importance of site-specific management strategies rather than a one-size-fits-all approach.

Outcome

The project provided valuable ecological evidence on how natural flood events influence food resources and waterbird communities over time.

These findings support more informed environmental flow planning and contribute to the development of targeted carp management strategies, helping maximise ecological benefits while maintaining the health and resilience of the Hattah Lakes ecosystem.

Impact

This project supports long-term wetland conservation by:

• Improving understanding of flood-driven ecosystem processes
• Identifying the relationship between food resources and waterbird populations
• Informing future environmental watering strategies
• Supporting adaptive invasive carp management
• Enhancing the long-term resilience and biodiversity of the Hattah Lakes wetland system

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