Living Murray Regional Evaluation Group B (Hume Dam to Yarrawonga Weir)

"June 2003".

Project Number: Regional Evaluation Group Assessment of reference point flow scenarios (part of MDBC the Living Murray project).

MDFRC item.

43 p.

1 of 2 reports associated with MDFRC project see (Ecological habitat condition assessment for zone e downstream of Lock 11 to upstream side of Lock 3).

1. Floodplain Vegetation Habitat Condition is substantially improved relative to the CURRENT flow regime, with increasing flows. The best increases in habitat condition occurred for the 1500 GL - B, 750 GL -C and 1500GL - C scenarios. 2. Overall, increasing flow will have a positive effect on Wetland Vegetation Habitat Condition; but only at the highest flows (1500 GL –B, 750 GL – C and 1500 GL-C). In particular, increased flows will improve the condition of vegetation in wetlands higher up on the floodplain. 3. Changing flows will only have a small effect on Waterbirds Habitat Condition. 4. Native fish are being impeded by other factors, including thermal pollution. Changes to the flow regime have little overall effect on Native Fish Habitat Condition. For a net improvement for Native Fish Habitat Condition in this reach it will be necessary to implement structural and operational changes to mitigate thermal pollution, re-snagging and the restoration of fish passage. Based on the outputs of the MFAT model, of the flow regimes tested the 1500 GL – B and 1500 GL – C scenarios would appear to deliver the best ecological outcomes for this reach of the Murray River.