Burdekin River (below Dam)

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Subcatchments

    Smaller subcatchments within the Burdekin River (below dam) catchment include:

  • Glendon Creek
  • Burdekin River
  • Bell Creek
  • Pine Creek
  • Dozer Creek
  • King Creek
  • Bonnie Doon Creek
  • Alligator Creek

Vegetation

Riparian Habitat

iTRARC analysis of Riparian Habitat indicates that this subcatchment has gone from relatively poor (C+) condition to very poor (D) condition. This is largely due to an increase in the amount of gullies/scalds in the subcatchment as well as floodplain and upper catchment clearing.

iTRARC Scores

Catchment Class 3 B
Maximum iTRARC Score 16 (A)
1970s Score 6 (C+)
2004 Score 0 (D)
Reduction in Ecosystem Services Minor
Increase in Potential for Erosion Large
Reasons for Change in Score
  • Clearing on headwater streams
  • Floodplain clearing
  • Increase in the number of low cover hillslopes
  • Large increase in the number of gullies/scalds

TRARC (field survey) scores = No TRARC scores for this subcatchment

Reference:Assessing the condition of Riparian Vegetation in the Burdekin catchment

Wetlands

As for the lower Burdekin River, the flow regime, water quality and aquatic habitat of the Burdekin River below the dam has been highly modified by irrigation releases of elevated water turbidity from the Burdekin Falls Dam. This is likely to have significantly affected ecological processes in the river. Although knowledge of the exact effects are limited, it appears to still be relatively healthy (Butler 2006), just highly modified from natural. The reach also includes three weir pools, the largest and most downstream of these – Clare Weir – restricts fish passage up the river, although a new fishway was installed there in 2006.

For more information see Burdekin River (below Dam) wetland condition summary

Water

SedNet Modelling of Water Quality

Model results for the Burdekin River (below the dam) sub-catchment are summarized as follows:

  • Subcatchment modelled area: 2,583sq. km.
  • Source contributions: Hillslope = 20%; Gully = 9%; Streambank = 72%
  • Area of subcatchment with <50% ground cover: 529 sq. km or 20% of subcatchment
  • Hillslope sediment supply: 590 kg/ha/yr
  • Total suspended sediment (flow weighted) supply: 772 kt/yr
  • Total suspended sediment supply (flow weighted ; normalized to area): 2990kg/ha/yr
  • Mean Annual Flow: 9,380,369 ML

Reference: Improved SedNet Modelling of Grazing Land in the Burdekin Catchment

Supplementation has had a major impact on hydraulic habitat of the Burdekin River below the dam due to unseasonal flows. This has resulted in a major change in water quality due to releases and spills of unnaturally turbid water from Burdekin Falls Dam.

Water Quality Monitoring

There are no water quality data available for the Burdekin River (below dam) catchment.

Relevant information of Water Quality Monitoring in the Lower Burdekin River Basin:

Environmental Uses and Values

Aquatic Ecosystems

The aquatic ecosystem values of the Burdekin River are considered to be Highly Disturbed (HD) due to the altered flow regime. Other parts of the Burdekin River (below dam) subcatchment are poorly known and while considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing, the biological communities are thought to remain in a healthy condition and ecosystem integrity is likely to be largely retained. No High Ecological Value (HEV) waters have been identified in the subcatchment.

The Directory of Important Wetlands lists the Burdekin-Bowen Junction and Blue Valley Weir Aggregations in this subcatchment. However, no wetlands were considered to be “effectively unmodified” (ANZECC 2000) and no HEV waters were identified in this subcatchment at this stage. However, the area is being further reviewed for their HEV features potential.

Stock Watering

Extensive cattle grazing. Use of water for stock watering.

Cultural and Spiritual

Custodial use of water resources by Jangga and Birri traditional owners.

References:

Landuse

Principle land uses within the Burdekin River (below Dam) subcatchment as a proportion of total area:

  • Grazing: 95%
  • Water: 3.5%
  • Irrigated Sugar: .8%
  • Irrigated horticulture & cropping: .5%
  • Conservation & minimal use: .4%
  • Urban & semi urban: Limited urban and semi urban activity use identified.

Land Condition

Definition of ABCD land condition framework

No data available for land condition in the Burdekin River (below dam) sub-catchment.

Ground Cover

No data available for Ground Cover in the Burdekin River (below dam) sub-catchment.

Resource Condition Summary

Burdekin River (below dam) is a small subcatchment where the land use is almost exclusively grazing on natural pastures. The condition of riparian habitat in the subcatchment has undergone further decline over the last 30 years due to clearing of the floodplain and headwater streams. The catchment was in poor (C) condition in the 1970s and by 2004 its condition had declined to very poor (D). The flow regime and aquatic habitat of the Burdekin River below the dam has been highly modified by water releases of elevated turbidity from the Burdekin Falls Dam for irrigation purposes further downstream. This, and the construction of three weir pools that restrict fish passage, is likely to have significantly affected ecological processes in the river.

Streambank erosion is identified by models as the major source of sediment and particulate nutrients affecting water quality from within the Burdekin River (below dam) subcatchment, while hillslope erosion is also predicted to contribute substantially to the total sediment load. The rate of soil erosion is predicted to be extremely high and well above the Basin average, while the total soil loss from the subcatchment to waterways is also comparatively very high. There are no rapid assessment data for land condition and ground cover available for the subcatchment. However, analyses of ground cover from satellite imagery identify large areas of bare ground and high vulnerability to 'D' condition, particularly in the upper reaches and immediately below the Burdekin Falls Dam. The mean ground cover across the subcatchment declined from 92% in 1999 to 69% in 2004, but had only recovered to 83% in 2006.

Water quality in the Burdekin River (below dam) subcatchment is predicted by models to be only slightly impacted by suspended sediment during wet season event flows. However, the sediment load at end-of-catchment is derived not only from this subcatchment, but from almost of the entire Burdekin River catchment. There are no water quality monitoring data, however, with which to compare the modelled concentrations and loads.

Burdekin River (below dam) is identified as a priority subcatchment for rehabilitation on the basis of the large areas of bare ground and vulnerable 'D' condition land, high rate of soil erosion and predicted contribution to the total sediment load within the basin.

Draft Environmental Values

The aquatic ecosystem values of the Burdekin River are considered to be Highly Disturbed (HD) due to the altered flow regime. Other parts of the Burdekin River (below dam) subcatchment are poorly known and while considered to be Slightly to Moderately Disturbed (SMD) as a consequence of the surrounding land use for cattle grazing, the biological communities are thought to remain in a healthy condition and ecosystem integrity is likely to be largely retained. No High Ecological Value (HEV) waters have been identified in the subcatchment. Little is known about the human use Environmental Values of water in the subcatchment, which are thought to be limited to use for stock watering and the cultural and spiritual values of the Jangga and Birri traditional owners.

Maps

References

BurdekinRiverbelowDam.jpg
Download Catchment Layer as *.kml (requires Google Earth)

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