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Case Studies 1. Kyeamba Creek 2. Liverpool Plains 3. Billabong Creek 4. Wanilla 5. Axe Creek 6. South Loddon Plains 7. Kamarooka 8. Lake Warden 9. Brymaroo Printing help |
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Kamarooka
Location: Central Victoria, 35 km north of Bendigo. Area: 100 km2. Rainfall: 420 mm. Land use Crop/pasture rotation, sheep grazing, scattered remnant trees. Reference: Hekmeijer et al. (2001) Salinity The catchment is not drained by a connected set of streams and salinity is expressed as a large area of shallow groundwater levels. After some time, these areas become saline and restrict or prevent crop growth. The area of salinity appears to expand and contract over several years according to increases and decreases in annual rainfall. Groundwater systems The recharge and discharge processes at Kamarooka are similar to those in SA and WA. Local groundwater systems in fractured rock aquifers discharge at subtle breaks in slope or in low-lying areas, e.g., local drainage lines. The moderate to low hydraulic conductivity combined with low hydraulic gradients means that the groundwater system is sluggish and hence can be severely affected by small increases in recharge. Management Modelling showed that conversion of crops to lucerne in the recharge zone near the top of the ridge would reduce recharge by more than 50% and this would reduce the area of shallow water levels within 20 years. A 90% reduction in recharge would significantly alter the extent of salt affected area. In fact, modelled results show that over 100 years a 90% reduction in recharge would lead to the catchment expressing no visible areas of dryland salinity. This indicates that changes in agronomic management can have a timely response. Engineering drains do not appear to be viable. Alternative industries, that can use saline water, e.g., seaweed, have also been independently proposed. |
Break-of-slope discharge area at Kamarooka Click for large conceptual model 
Salt crusting in the discharge area at Kamarooka |
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