Waterways are one of the most significant forces shaping our ecosystem and intrinsically linked with the overall health of the environment. Understanding our rivers and estuaries with a view to management and maintenance of both form and function, whilst balancing economic and social values, is one of the most important roles of the Department of Water.
The condition and stability of our waterways is dependent on a complex and dynamic network of interactions between biotic (bacteria, algae, plants and animals) and abiotic features (sediments, rocks, climatic features, water flow, chemicals and physical form), which often varies greatly between regions (variations in rainfall, temperature, altitude, geology, depth, flow) and over time (i.e. seasonal changes). As such, to determine how healthy a river or estuary is we must look at more than just the quality of the water or sediment, it requires understanding of the:
- Diversity of habitats and biota (a well balanced ecosystem)
- Stability of ecological processes (i.e. energy and nutrient dynamics)
- Linkages within the waterway (i.e. for migration of animals) and between the waterway and catchment
To better understand, assess and manage our waterways the Department of Water is looking at multiple approaches, using both monitored and modelled techniques. The Department has a significant focus on water quality and quantity, although it is investing increasing time and effort investigating sediment quality, algae and more recently plants and animals, including macroinvertebrates, fish and crayfish, seagrass and fringing vegetation.
Holistic, multiple-parameter approaches for assessing waterway health are also being employed, where a range of information is collected for each system to determine overall ecological health. This approach examines not only the condition of particular aspects of the waterway (such as water quality and fish health), but attempts to determine the ecological integrity of the system taking into account catchment inputs and interactions between components of the system. This approach is being undertaken for both rivers and estuaries.
Understanding of waterways enables the Department to better assess the health status of our systems, especially in relation to common threats and risks to our waterways. For more information about the techniques utilised to assess waterways see monitoring and assessing waterways health.