Surface water resources reliant on groundwater
Tasmania's groundwater and surface water resources are highly connected. A large proportion of annual streamflow comes from springs and direct discharge of groundwater into the beds and banks of watercourses.
Many lakes, wetlands and estuaries are also significantly connected to and reliant on groundwater.
The most highly connected systems are those in
where cave systems and enlarged fractures supply water to springs, surface streams and lakes, and receive water from surface catchments. Landscapes in coastal sands, alluvium and basalt also contain highly to moderately connected groundwater and surface water resources.
Ecosystems in rivers, springs, lakes, wetlands, estuaries and caves which depend on groundwater inputs (along with terrestrial vegetation communities using groundwater) are called
Groundwater Dependent Ecosystems.
Classification of Connected Water Regions in Tasmania
(from Sheldon 2011)
Regionalisation and Risk Assessment for Groundwater and Surface Water Resources - Final Report
Streams and aquifers are connected in different ways in different circumstances, depending on the local hydrology, geology and landforms.
This report maps the distribution of connected systems across Tasmania, and assesses the vulnerability of surface water resources to groundwater extraction, and vice-versa.
Groundwater and Surface Water Connectivity in Tasmania Preliminary Assessment and Risk Analysis (10Mb)
Regional assessments of connected water systems - Final reports for the Duck River catchment (Smithton Syncline) and Sassafras-Wesley Vale
Surface and groundwater resources of the Duck River valley (within the Smithton syncline) are highly connected through a karstic groundwater system. Groundwater also forms an important source of both surface streamflow and water extracted for irrigation at Sassafras-Wesley Vale.
These reports document the nature and hydrological processes of the surface and groundwater systems in both areas, along with their groundwater dependent ecosystems.
The Smithon Report is available here:
Groundwater and Surface Water Connectivity in Tasmania - Smithton (9Mb)
The Wesley Vale Sassafras Report is available here:
Groundwater and Surface Water Connectivity in Tasmania - Wesley Vale - Sassafras (20Mb)