Environmental Scan of the Namoi River Valley. Report for the Department of Land and Water Conservation and the Namoi River Management Committee. Thoms, M., Norris, R., Harris, J., Williams, D. & Cottingham, P. |
1 INTRODUCTION 1
Figures
Figure 1: Components of a river system 6
Figure 2: Processes in upland rivers 6
Figure 3: Processes in lowland constrained rivers 7
Figure 4: River – floodplain interactions 7
Figure 5: River zones in the Namoi catchment 14
Figure 6: Long-term monthly flows (observed and simulated natural) for the Namoi River system: a) Peel River; b) Gunnedah, and c) Narrabri. Source: DLWC, Integrated Quantity and Quality Model (IQQM) 18
Figure 7: Namoi River Catchment Index of Stream Condition. * - Water Quality and Aquatic Life sub-indices could not be calculated. 32
Figure 8: Summary of key issues confronting riverine management in the Namoi catchment 45
Tables
Table 1: Geomorphological zones of the Namoi Catchment. 15
Table 2: Total Annual Flow Statistics for the Namoi River (ML). 15
Table 3: Changes in average return intervals of floods for selected sites in the Namoi River system. Source: DLWC, Integrated Quantity and Quality Model (IQQM) 17
Table 4: Characteristics of sites sampled in the Namoi River Catchment. 20
Table 5: Physical habitat assessment of sites in the Namoi River Catchment. 21
Table 6: Abundance of fish species recorded at sites in the Namoi River catchment. Data from the NSW Rivers Survey (Harris and Gehrke 1997). Surveys 1 – 5 occurred from October 1994 to April 1999. 27
Table 7. Summary of dominant riparian species in various reaches of the Namoi system (Source DWR 1992). 29
Table 8: Five-point scale for indicator measurements. 31
Table 9: Major threats to environmental condition of the 7 river regions in the Namoi 34
Table 10: Interaction of effects associated with degrading influences 37
Table 11: Combined assessment scores for sites across the Namoi catchment 46
Table 12: Physical indicators of river system condition 47