Human activities alter the quantity, quality and pace of river flows; in turn affecting other ecological processes. To mitigate the ecological impacts of these altered river flows, environmental managers have implemented environmental flows. This PhD study aims to assess the influence of environmental flows as a rehabilitation strategy using the Moorabool River as a case study. This overarching aim will be addressed by focusing on three key elements: examining the influence of water capture on streamflow by farm dams; how flow dynamics change over in-stream barriers with altered river flow; and developing a mapping tool, which will assist future stakeholder engagement activities by providing a shared understanding of the complexity of property types and responsibilities in the catchment (both formally denoted as well as perceived).
The impacts of land-use change on streamflow is a topic of increasing scientific and policy interest, particularly under changing climatic conditions. In rural areas, the interception of catchment runoff by farm dams is one of the more important land-use changes and hence sources of streamflow change. Additionally, the collective impact of dams can disrupt river connectivity.
The influence of farm dams on streamflow within the Moorabool River catchment is poorly understood. I will research the spatial and temporal distribution of farm dams and their morphological characteristics. Historical and future streamflow will be assessed using methods that consider the time-varying evolution of farm dam numbers.
Additional challenges to river disruption are in-stream barriers. My research will assess how environmental and natural flows influence the water connectivity over fish barriers, flows and water quality. I will address this aim in three ways: 1) Characterizing critical ecological barriers, 2) measure the hydraulics of water flowing varying fish barriers, and 3) estimate the passability of the barrier by correlating the flows and known swimming abilities of fish species.