Salinity Province 120, Upper Loddon Volcanic Plains

The relatively large Upper Loddon Volcanic Plains Salinity Province extends from the volcanic plain adjacent to Cain Curren reservoir in the north to the meta-sedimentary ridges near Creswick in the south. Broadly, landuse varies with latitude and related rainfall distribution, the north being flatter and drier has significant cropping established whilst the south has significant horticulture farming. The local to intermediate scale Groundwater Flow Systems (GFSs) underlying the province consist of fractured volcanic aquifers with associated scoria cones overlying an extensive ‘deep lead’ (paleo-river channel) system. The deep lead was the target of extensive gold mining and now provides a source of irrigation water. Salinity occurs at three distinct areas; Long swamp (near Joyces Creek), Glengower and Smeaton. Each area is characterised by being a low-lying drainage basin with limited outflow, with likely groundwater discharge coming up from the intermediate scale GFSs.

Fenced tree and perennial pasture planting for recharge control has been undertaken with some success. This should be coupled with the fencing off discharge areas so they can be carefully managed (with minimal grazing etc.) separately to the non-saline areas.