Kirk River

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Subcatchments

Smaller subcatchments within the Kirk River Catchment include:

  • Two Mile Creek
  • Fish Creek
  • Connoly Creek
  • Elphinstine Creek
  • Kirk River

Vegetation

Riparian Habitat

iTRARC analysis of Riparian Habitat indicates that this subcatchment was in poor condition in the 1970s largely due to gullying and gaps in the riparian corridor. This condition has worsened with gullying becoming more extensive and increasing gaps in the riparian corridor. The field survey site also indicates poor condition, however more sites would be required to capture the diversity of riparian conditions in this catchment.

iTRARC Scores

Catchment Class 3 E
Maximum iTRARC Score 10 (B)
1970s Score 4 (C)
2004 Score 0 (D)
Reduction in Ecosystem Services Very Minor
Increase in Potential for Erosion Moderate
Reasons for Change in Score
  • Reduction in tree cover in the headwaters
  • Increased % of gap in the riparian corridor of the main channel
  • Increased gullies / scalding
  • Increase in the number of low cover hill slopes adjacent to the channel network

TRARC (field survey) scores

Survey SiteScoreRegenerationWeeds
Two Creeks Ck59.7 (C)1 (C)0 (A)
Average 59.7 (C)

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

Wetlands

This is a largely sandy, dry seasonal creek system with very limited aquatic habitat availability, though the area is poorly known ecologically. Condition is not well known though thought to be similar to adjoining sub-divisions. Tilapia were found here in 2006 in a small isolated waterhole (Veitch et al. 2006).

Reference: Assessing the condition of Wetlands in the Burdekin catchment

For more information see Kirk River wetland condition summary

Water

SedNet Modelling of Water Quality

Model results for the Kirk River subcatchment are summarized as follows:

  • Subcatchment modelled area: 1,016 sq. km.
  • Source contributions: Hillslope = 83%; Gully = 15%; Streambank = 2%
  • Area of subcatchment with <50% ground cover: 355 sq. km or 35% of subcatchment
  • Hillslope sediment supply: 656 kg/ha/yr
  • Total suspended sediment (flow weighted) supply: 80 kt/yr
  • Total suspended sediment supply (flow weighted; normalized to area): 791 kg/ha/yr
  • Total suspended sediment end-of-subcatchment (flow weighted) yield: 76 kt/yr
  • Event Mean Concentration (EMC - flow weighted): 895 mg/L
  • Mean Annual Flow: 84,713 ML

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

Hillslope erosion is identified as the major source of sediment and particulate nutrients affecting water quality within the Kirk River subcatchment (83%), and is predicted to contribute 656 kg/ha/yr. It is estimated that approximately 35% of the subcatchment has poor ground cover (<50%). Gullies are predicted to contribute approximately 15% of the total suspended sediment load. Total sediment losses from all sources is predicted to be high (791 kg/ha/yr). Similarly, the event mean concentration of suspended sediment is predicted to be high (895 mg/L).

Water Quality Monitoring

The monitoring site in the Kirk River catchment is located downstream from the Burdekin Falls Dam Road at Kirk River Station and has been sampled by the NQ Dry Tropics Volunteers program for 2 years. The catchment area for this monitoring site is 50 sq km, of which 99.3% is used for grazing. Suspended sediment concentrations for the Kirk River have been relatively low (mean concentration of 99 mg/L) over the monitoring period compared to other catchments within the Burdekin rangelands. This concentration is considerably lower than that predicted by the SedNet model (895 mg/L), although additional monitoring is required to strengthen this comparison.

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

Environmental Values

Aquatic Ecosystems

The aquatic ecosystem values of Kirk River 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) areas have been identified in the subcatchment.

Stock Watering

Water supply for production of healthy livestock.

Cultural and Spiritual

Custodial use of water by Birri traditional owners.

References:

Landuse

Principle land uses within the Kirk River subcatchment as a proportion of total area:

  • Grazing: 97.25%
  • Conservation & minimal use: 2.1%
  • Water: .3%
  • Mining: .3%
  • Urban & semi urban: limited urban & semi urban water activity use identified.

Grazing Land

Kirk River is a relatively small subcatchment where land use is dominated by grazing on natural pastures.

Land Condition

Definition of ABCD land condition framework

Results of a Rapid Land Condition Assessment (adopted from Hassett et al. 2000) are presented below. The assessment has been devised to subjectively characterise condition while traversing the BDT region by vehicle. The data are based on a total of 4666 observations across the Burdekin region between 2004 and 2007.

The data were collected to provide independent information on land condition and provide a regional perspective. Resource assessment data are most useful when interpreted with other sources of data e.g. time-series remote sensing, modelling and water quality monitoring.

The estimated condition of the Kirk River sub-catchment is proportioned as follows:

  • A Condition: 3%
  • B Condition: 26%
  • C Condition: 50%
  • D Condition: 20%

Data from the Kirk River sub-catchment is based on 120 observations.

On the basis of the rapid assessment, the Kirk River sub-catchment is estimated to have the largest proportion of land in poor (C) condition (50%), followed by fair (B) condition (26%) and very poor (D) condition land (20%). 3% of observed land was in good (A) condition.

Ground Cover

Ground Cover in the Kirk River sub-catchment is proportioned as follows:

  • (BC) Bare Cover: 6%
  • (LC) Low Cover: 41%
  • (MC) Moderate Cover: 39%
  • (HC) High Cover: 14%
  • (VHC) Very High Cover: 0%

Data from the Kirk River sub-catchment are based on 118 observations.

On the basis of the rapid assessment (2004-2007), the Kirk River sub-catchment is estimated to have the highest proportion of land within the low (LC) ground cover category (41%), followed by moderate (MC) cover (39%) and high (HC) cover (14%) categories. 6% of land was estimated to fall into the bare cover (BC) category.

Resource Condition Summary

Kirk River is a relatively small subcatchment where land use is dominated by grazing on native pastures. Conservation and minimal use comprises around 2% of the subcatchment, while there are many abandoned and operational mines throughout the subcatchment. Riparian condition in this subcatchment was already poor (C) in the 1970s and has deteriorated further over the last 30 years. Its current condition is assessed as very poor (D) due to increased gaps in the riparian corridor, clearing along headwater streams and an increase in gullying adjacent to creeks. The rivers and creeks are largely sandy, dry seasonal systems with limited habitat availability. Very little is known about the ecology and condition of aquatic habitats.

Hillslope erosion is identified by models as the major source of sediment and particulate nutrients affecting water quality within the Kirk River subcatchment. The rate of soil erosion is predicted to be moderate and above the basin and BWQIP region average, while the total soil loss to waterways from the subcatchment is comparatively low due to its small area. Grazing land condition is assessed as having a high proportion in poor (C) condition. Large proportions of land in fair (B) and very poor (D) condition were also apparent. This is also reflected in the ground cover assessment (2004-07). Analysis of ground cover from satellite imagery (reference) identifies some areas of land that are vulnerable to 'D' condition in the centre of the subcatchment, along Barrabas Creek, and the lower reaches of Elphinstone Creek. Nevertheless, while the mean ground cover across the entire subcatchment declined from 97% in 1999 to 71% in 2004, it had recovered to 90% in 2006.

Water quality in the Kirk River subcatchment is predicted by models to have moderately elevated sediment concentrations during wet season event flows. While water quality monitoring data have recorded only low concentrations of sediments from the Kirk River, but this monitoring site is located along the middle reaches of the river and represents only a small part of the total subcatchment. Additional water quality monitoring sites in this subcatchment would be useful to verify model predictions.

Draft Environmental Values

The aquatic ecosystem values of the Kirk River 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 Birri traditional owners.

Maps

References

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

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