Management of Karst areas

This information has been developed from the publications:

An assessment of the Geological/Geomorphological Significance of Private Land in the Shire of Portland (1981) by N. Rosengren, J Mallen, T Shepherd.

Geological heritage sites, including sites of geomorphological interest and volcanic heritage sites, are under regular revision by the Geological Society of Australia, especially in the assessment of significance and values. Reference should be made to the most recent reports. See the Earth Science Heritage section of the Geological Society of Australia website (external link) for details of geological heritage reports, and a bibliography.

Although there is an extensive literature on stratigraphy, lithology, geological structure and ground water relevant to Portland Shire, there is little published material on karst processes such as speleognesis and cave sedimentation of the limestones of western Victoria.

Karst is dependent on a dynamic interrelationship between land and water resources. Many of the values of caves and karst are based on a limited, non-renewable and fragile resource. It is important to note that for most of the karst management issues, private and public land boundaries are not relevant. Strategies for management must consider particularly the extensive drainage networks which may occur beneath the ground surface. A summary is provided of the main considerations in land use planning in a karst area.

Management Issues

1. Cave and Ground Water Pollution from Rubbish Dumping
2. Ground Water Pollution from Septic Tanks and Industry
3. Water Table lowering due to excessive use or changed land use practices
4. Quarrying
5. Building on inappropriate sites
6. Agricultural Practices
7. Recreational and access issues

The sites delineated on limestone areas are of two types - area sites and specific sites. Specific sites indicate known features such as caves or sinkholes which have at least been recorded by the Victorian Speleological Association. Area sites indicate broader karst landscapes which have not been investigated but undoubtedly contain other specific features of interest. However, these large areas must be regarded as an essential element of the total karst landscape for management purposes.

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