Salinity Province 54, Kerang Lakes

The large Kerang Lakes Salinity Province is dominated by the terminal lake system of the Avoca and Loddon rivers. It is one of only two provinces located across a CMA boundary, with a small part of the far Northwest of the Province located within the Mallee CMA area (see map below). While the area concerned is geographically quite small, it contains a number of significant areas of mapped salinity; the largest of these is also partially located within the two adjacent CMA areas. These saline areas have been included in this Province because their characteristics and attributes are more closely related to those of the remainder of the Province than to those of the closest province in the Mallee CMA area.

Soil Salinity has developed where broad shallow watertables associated with a regional scale Groundwater Flow System (GFS) intersect the existing terminal ephemeral lake system. Dryland Salinity has also developed in low-lying areas including swales, dry shallow lakes and around the lake margins, relating to local scale GFSs in the Quaternary aeolian, lake, evaporite and shallow alluvial sediments which overlie the regional scale GFS. The increased hydraulic load from irrigation, the channel systems and flooding of the lakes and wetlands compounds this salinity. Salinity is the main risk to the fresh water ecology of the Kerang Wetlands, which are RAMSAR listed and affected by direct saline intrusions, disposal of saline drainage water and isolation from natural flushing flows. Salinity is managed through an integrated program that includes groundwater monitoring, improved irrigation water-use efficiency; better surface drainage, strategic flushing of wetlands, targeted groundwater pumping and environmental protection works.