NRM South

Freshwater

Southern Tasmania has an abundance of freshwater and freshwater dependent values. NRM South is working with the community throughout the region to better understand, protect and manage these diverse freshwater assets.

Freshwater environmental values

Freshwater and freshwater dependent values in Southern Tasmania include major rivers and river systems, and diverse wetlands and groundwater dependent ecosystems of national and international conservation significance.

Major freshwater  and freshwater dependent assets in the southern region include:

  • 4 Ramsar listed wetlands - Moulting Lagoon and Apsley Marshes, Interlaken Lakeside Reserve and Pittwater/Orielton Lagoon  
  • 27 wetlands listed on the Directory of Important Wetlands Australia. These occur predominantly in the Central Highland Lakes/Upper Derwent area, the Derwent Estuary - Bruny catchment, Swan-Apsley and upper Macquarie Catchments.
  • Many cave and karst systems, buttongrass and sphagnum moorlands, sub-surface streams, deflation basins, coastal sand aquifers and groundwater dependent lakes, lagoons and rivers.
  • Many threatened, rare or endemic freshwater fauna. Examples include: a wide diversity of endemic fish species (Galaxiids) the majority of which are threatened, 14 species of burrowing freshwater crayfish (including 7 threatened) which are important in maintaining the health and carbon storage capacity of buttongrass moorlands, and endemic and threatened frog species (including the green and gold frog, Tasmanian tree frog, the moss froglet and Tasmanian froglet).

The region’s rivers and wetlands are also breeding grounds and nurseries for many species including frogs, fish, birds and invertebrates, making them critical for maintaining biodiversity values. They are also significant places for Aboriginal cultural heritage.

Freshwater industry and economic values

The region’s rivers and wetlands are critical in maintaining water quality, replenishing wetland, river and groundwater systems, pest control and mitigating against climate change by buffering against flood, drought and storms and helping to stabilize coastal shorelines.

They provide water necessary for agricultural irrigation, natural and plantation forestry, riverine and inland aquaculture, hydro-electric power generation, mining and ore processing. Our waterways support diverse tourism and recreation activities, including boating, fishing, bushwalking and birding.

Most of the region enjoys access to clean domestic and drinking water which requires only minimal treatment.

Managing Freshwater Systems

The condition of our rivers and wetlands reflects both natural processes such as flood, drought, and fire, as well as land management and land and water use. Our waterways and water bodies are facing pressure and resource demand from increasing urbanizsation, changing agricultural demands and a changing climate. Some are managed in Conservation Areas but many others are under threat or in poor condition. Unlike marine and terrestrial systems there are limited opportunities for protecting rivers and wetlands in reserves, although many important wetlands now enjoy protection under Tasmania’s Nature Conservation Act 2002 and Forest Practices Regulations 2007. This reduces the risk of wetlands being cleared or drained.

Effective freshwater system management takes into account the following considerations:

  • The need to protect the headwaters of rivers which influence downstream ecosystem processes, including in estuaries and coastal areas
  • Land and water use intensification or change, including increased dryland irrigation, conversion to tree plantations and the expansion of dams for agriculture and domestic water use
  • Peri-urban development and associated land clearing, loss of riparian vegetation, road construction, stormwater run-off and pollution from septic and reticulated sewage systems
  • Point source pollution from inland aquaculture, wastewater systems and the region’s many industries, including paper mills, breweries, mines, quarries and smelters
  • Invasive freshwater pests and diseases such as Redfin perch, trout, willows, Canadian pond weed, chytrid frog disease, Phytophthora root rot and platypus mucor disease. Climate change has the potential to exacerbate many of these threats
  • Artificial in-stream structures such as dams, culverts, weirs, and sand and gravel quarries which impact on downstream flows and water quality, lake levels, fish & eel passage and can cause stream bank erosion
  • Changes in rainfall, frequency and distribution through climate change, all of which are resulting in changes to flows and coastal erosion processes

What are we doing to protect our Freshwater System

NRM South is working to better understand, protect and manage our diverse freshwater assets. We do this in partnership with stakeholders across the region, including all levels of government, industry, research organisations, NGOs and the community. This includes a range of activities through our Healthy Catchments and Coasts program which are addressing the spread of introduced weed species, implementing management plans, protecting threatened species and habitat, improving water quality and improving land use planning and decision making.