Lachlan Area Commonwealth Environmental Water Holder’s Science Program (Flow Monitoring, Evaluation and Research): Annual Report 2024-25

Flow-Monitoring, Evaluation and Research (Flow-MER) is the Commonwealth Environmental Water
Holder’s (CEWH) Science Program. Flow-MER is the primary means by which the Commonwealth
Environmental Water Holder (CEWH) evaluates the planning and use of Commonwealth
environmental water. The Flow-MER 2.0 Program builds on a decade of coordinated ecological
response monitoring across the Murray-Darling Basin. It extends and refines the Long-Term
Intervention Monitoring (LTIM) Project (2014–2019) and the Flow-MER 1.0 Program (2019–2024),
preserving the integrity of long-term datasets and ensuring consistent data collection and analysis.
This continuity allows for robust trend detection and provides an evidence base to assess the
contribution of environmental water to ecological health and Basin Plan objectives. Monitoring and
evaluation under Flow-MER 2.0 supports five central goals:
• To evaluate the contribution of Commonwealth environmental water to the environmental
objectives of the Murray–Darling Basin Authority’s Environmental Watering Plan.
• To assess the ecological outcomes of Commonwealth environmental watering at Area scale.
• To infer outcomes in unmonitored areas of the Basin using evidence from the Project Areas.
• To support adaptive management by providing timely and relevant information to water
managers.
• To maintain and strengthen the long-term datasets essential for evaluating change in the
Basin’s ecosystems.
The purpose of this report is to document and communicate ecological responses to the delivery of
Commonwealth environmental water in the Lachlan Area during the 2024–25 monitoring year.
Reporting under the Flow-MER 2.0 Program aligns with Monitoring and Evaluation Objectives
established by the Commonwealth Environmental Water Holder (CEWH) and responds directly to Key
Evaluation Questions (KEQs) at both the Area and Basin scales. The report contributes towards
ongoing efforts to evaluate how Commonwealth environmental water supports ecological outcomes
across the Murray–Darling Basin (MDB). It is also part of a broader monitoring, evaluation and
research framework designed to inform adaptive water management, assess ecological responses,
and meet statutory reporting obligations under the Water Act 2007 and the Murray–Darling Basin
Plan (2012).
This Annual Report provides a detailed account of ecological responses observed over the 2024-25
water year in the Lachlan Area, and pairs with a Summary Report that provides a synthesis of these
findings. By combining detailed monitoring results with interpretive synthesis both reports provide a
comprehensive picture of ecological responses to environmental watering in the Lachlan catchment.
This integrated approach deepens understanding of how Commonwealth environmental water
supports the region’s ecosystems and guides adaptive management to ensure future watering
actions deliver effective ecological benefits.
The Annual report is designed as a record of the supporting technical material for the Summary
report (DCCEEW 2025).