Salinity Province 81, Mortlake Caramut

The Mortlake_Caramut Salinity Province is a large province which covers an extensive landscape of basalt plains (older phase volcanics), volcanic eruption points and stony rises country (later phase volcanics). It has a regional scale Groundwater Flow System (GFS) on the basalt plains and local scale GFSs associated with the eruption points and stony rises.

Salinity occurrence is of both primary and secondary type. High watertables, waterlogged swamps, depressions and saline discharge to natural salt lakes and drainage lines are features of this province, but widespread clearing allowed greater recharge to the groundwater systems, causing the subsequent expansion of these natural salinity features. Fresh groundwater associated with the eruption points and stony rises is often an important water resource, so management to reduce recharge on these areas may conflict with protecting this drought resistant water resource.

The older basalt plains generally hold brackish or saline groundwater that is unlikely to respond to vegetation control of recharge, so ‘living-with-salt’ and protecting wet areas in the landscape should be the priority of any management planning and activities.